http://www.cnblogs.com/QLJ1314/archive/2013/03/04/2942703.html
有个博友问多个文件上传的问题，正好最近我也遇见这样的问题，刚好解决，费了好大的劲儿呀！终于皇天不负有心人啊，写到上边也让自己记住，希望这对那位博友有所帮助吧，也希望各位大牛看到后提出意见。大家互相学习，共同努力，加油！好了废话不多说了，开始吧，上例子。
1.最简单的单文件上传(没花头)
效果图：
说明：这是最基本的文件上传，在asp.Net1.x中没有这个FileUpload控件，只有html的上传控件，那时候要把html控件转化为服务器控件，很不好用。其实所有文件上传的美丽效果都是从这个FileUpload控件衍生，第一个例子虽然简单却是根本。
后台代码：
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void bt_upload_Click(object sender, EventArgs e)
{
try
{
if (FileUpload1.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
string filepath = FileUpload1.PostedFile.FileName;
string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
string serverpath = Server.MapPath("images/") + filename;
FileUpload1.PostedFile.SaveAs(serverpath);
this.lb_info.Text = "上传成功！";
}
}
catch (Exception ex)
{
this.lb_info.Text = "上传发生错误！原因是：" + ex.ToString();
}
}
}
前台代码：
<table style=" 343px">
<tr>
<td style=" 100px">
单文件上传</td>
<td style=" 100px">
</td>
</tr>
<tr>
<td style=" 100px">
<asp:FileUpload ID="FileUpload1" runat="server" Width="475px" />
</td>
<td style=" 100px">
<asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="上传" /></td>
</tr>
<tr>
<td style=" 100px; height: 21px;">
<asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="183px"></asp:Label></td>
<td style=" 100px; height: 21px">
</td>
</tr>
</table>
2.多文件上传
效果图：
后台代码：
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void bt_upload_Click(object sender, EventArgs e)
{
if ((FileUpload1.PostedFile.FileName == "" && FileUpload2.PostedFile.FileName == "")&&FileUpload3.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
HttpFileCollection myfiles = Request.Files;
for (int i = 0; i < myfiles.Count; i++)
{
HttpPostedFile mypost = myfiles[i];
try
{
if (mypost.ContentLength > 0)
{
string filepath = mypost.FileName;
string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
string serverpath = Server.MapPath("images/") + filename;
mypost.SaveAs(serverpath);
this.lb_info.Text = "上传成功！";
}
}
catch (Exception error)
{
this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
}
}
}
}
}
前台代码：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html Xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>多文件上传 清清月儿http://blog.csdn.Net/21as.Net/</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<table style=" 343px">
<tr>
<td style=" 100px">
多文件上传</td>
<td style=" 100px">
</td>
</tr>
<tr>
<td style=" 100px">
<asp:FileUpload ID="FileUpload1" runat="server" Width="475px" />
</td>
<td style=" 100px">
</td>
</tr>
<tr>
<td style=" 100px">
<asp:FileUpload ID="FileUpload2" runat="server" Width="475px" /></td>
<td style=" 100px">
</td>
</tr>
<tr>
<td style=" 100px">
<asp:FileUpload ID="FileUpload3" runat="server" Width="475px" /></td>
<td style=" 100px">
</td>
</tr>
<tr>
<td style=" 100px">
<asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="一起上传" />
<asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="183px"></asp:Label></td>
<td style=" 100px">
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
3.客户端检查上传文件类型(以上传图片为例)
效果图：
后台代码和1.最简单的单文件上传一样；
前台代码：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html Xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>清清月儿 .Net/21as.Nethttp://blog.csdn.Net/21as.Net</title>
<script language="Javascript">
function Check_FileType()
{
var str=document.getElementById("FileUpload1").value;
var pos = str.lastIndexOf(".");
var lastname = str.substring(pos,str.length)
if (lastname.toLowerCase()!=".jpg" && lastname.toLowerCase()!=".gif")
{
alert("您上传的文件类型为"+lastname+"，图片必须为.jpg,.gif类型");
return false;
}
else
{
return true;
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<table style=" 343px">
<tr>
<td style=" 104px">
文件上传判断</td>
<td style=" 100px">
</td>
</tr>
<tr>
<td style=" 104px">
<asp:FileUpload ID="FileUpload1" runat="server" Width="400px" />
</td>
<td style=" 100px">
<asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="上传" OnClientClick="return Check_FileType()"/></td>
</tr>
<tr>
<td style=" 104px; height: 21px;">
<asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="183px"></asp:Label></td>
<td style=" 100px; height: 21px">
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
说明：点击上传时先触发客户端事件Check_FileType；
4.服务器端检查上传文件类型(以上传图片为例)
效果图：
后台代码：
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void bt_upload_Click(object sender, EventArgs e)
{
try
{
if (FileUpload1.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
string filepath = FileUpload1.PostedFile.FileName;
if (IsAllowedExtension(FileUpload1) == true)
{
string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
string serverpath = Server.MapPath("images/") + filename;
FileUpload1.PostedFile.SaveAs(serverpath);
this.lb_info.Text = "上传成功！";
}
else
{
this.lb_info.Text = "请上传图片";
}
}
}
catch (Exception error)
{
this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
}
}
public static bool IsAllowedExtension(FileUpload hifile)
{
string strOldFilePath = "", strExtension = "";
string[] arrExtension = { ".gif", ".jpg", ".jpeg", ".bmp", ".png" };
if (hifile.PostedFile.FileName != string.Empty)
{
strOldFilePath = hifile.PostedFile.FileName;
strExtension = strOldFilePath.Substring(strOldFilePath.LastIndexOf("."));
for (int i = 0; i < arrExtension.Length; i++)
{
if (strExtension.Equals(arrExtension[i]))
{
return true;
}
}
}
return false;
}
}
5.服务器端检查上传文件类型(可以检测真正文件名)
其实方法4并不好，因为用户可以把XXX.txt伪装为XXX.jpg。
效果图：
后台代码：
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page
{
//清清月儿 http://blog.csdn.Net/21as.Net
protected void Page_Load(object sender, EventArgs e)
{
}
protected void bt_upload_Click(object sender, EventArgs e)
{
try
{
if (FileUpload1.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
string filepath = FileUpload1.PostedFile.FileName;
if (IsAllowedExtension(FileUpload1) == true)
{
string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
string serverpath = Server.MapPath("images/") + filename;
FileUpload1.PostedFile.SaveAs(serverpath);
this.lb_info.Text = "上传成功！";
}
else
{
this.lb_info.Text = "请上传图片";
}
}
}
catch (Exception error)
{
this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
}
}
public static bool IsAllowedExtension(FileUpload hifile)
{
System.IO.FileStream fs = new System.IO.FileStream(hifile.PostedFile.FileName, System.IO.FileMode.Open, System.IO.FileAccess.Read);
System.IO.BinaryReader r = new System.IO.BinaryReader(fs);
string fileclass = "";
byte buffer;
try
{
buffer = r.ReadByte();
fileclass = buffer.ToString();
buffer = r.ReadByte();
fileclass += buffer.ToString();
}
catch
{
}
r.Close();
fs.Close();
if (fileclass == "255216" || fileclass == "7173")//说明255216是jpg;7173是gif;6677是BMP,13780是PNG;7790是exe,8297是rar
{
return true;
}
else
{
return false;
}
}
}
6.上传文件文件名唯一性处理(时间戳+SessionID)
效果图：
说明：年月日时分秒+临时session+原文件名 如果大家怕还会重复可以加GUID
后台代码：
try
{
if (FileUpload1.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
string filepath = FileUpload1.PostedFile.FileName;
string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
string serverpath = Server.MapPath("images/") + System.DateTime.Now.ToString("yyy-MM-dd-hh-mm-ss") + Session.SessionID + filename;
FileUpload1.PostedFile.SaveAs(serverpath);
this.lb_info.Text = "上传成功！";
}
}
catch (Exception error)
{
this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
}
注：GUID的方法：Guid myGuid=Guid.NewGuid();
7.上传图片生成等比例缩略图
效果图：
缩略图代码：
ImageThumbnail.cs
using System;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
public class ImageThumbnail
{
public Image ResourceImage;
private int ImageWidth;
private int ImageHeight;
public string ErrorMessage;
public ImageThumbnail(string ImageFileName)
{
ResourceImage = Image.FromFile(ImageFileName);
ErrorMessage = "";
}
public bool ThumbnailCallback()
{
return false;
}
// 方法1，按大小
public bool ReducedImage(int Width, int Height, string targetFilePath)
{
try
{
Image ReducedImage;
Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
ReducedImage = ResourceImage.GetThumbnailImage(Width, Height, callb, IntPtr.Zero);
ReducedImage.Save(@targetFilePath, ImageFormat.Jpeg);
ReducedImage.Dispose();
return true;
}
catch (Exception e)
{
ErrorMessage = e.Message;
return false;
}
}
// 方法2，按百分比 缩小60% Percent为0.6 targetFilePath为目标路径
public bool ReducedImage(double Percent, string targetFilePath)
{
try
{
Image ReducedImage;
Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
ImageWidth = Convert.ToInt32(ResourceImage.Width * Percent);
ImageHeight = (ResourceImage.Height)*ImageWidth/ ResourceImage.Width;//等比例缩放
ReducedImage = ResourceImage.GetThumbnailImage(ImageWidth, ImageHeight, callb, IntPtr.Zero);
ReducedImage.Save(@targetFilePath, ImageFormat.Jpeg);
ReducedImage.Dispose();
return true;
}
catch (Exception e)
{
ErrorMessage = e.Message;
return false;
}
}
}
后台代码：
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void bt_upload_Click(object sender, EventArgs e)
{
try
{
if (FileUpload1.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
string filepath = FileUpload1.PostedFile.FileName;
string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
string serverpath1 = Server.MapPath("images/") + filename;
string serverpath2 = Server.MapPath("images/") + System.DateTime.Now.ToString("yyy-MM-dd-hh-mm-ss") + Session.SessionID + filename;
FileUpload1.PostedFile.SaveAs(serverpath1);
ImageThumbnail img = new ImageThumbnail(filepath);
img.ReducedImage(0.4, serverpath2);//0.4表示缩小40%
this.lb_info.Text = "上传成功！";
}
}
catch (Exception error)
{
this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
}
}
}
8.上传图片加水印(文字水印，图片水印，文字+图片水印)
效果图：
原图
水印
给图片加水印以后（注意右上角+正下方）
代码：
DrawImg.cs 出自http://www.codeproject.com/csharp/watermark.asp
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
public class DrawImg
{
private string WorkingDirectory = string.Empty ; //路径
private string ImageName = string.Empty; //被处理的图片
private string ImageWater = string.Empty; //水印图片
private string FontString = string.Empty; //水印文字
enum DealType{NONE,WaterImage,WaterFont,DoubleDo}; //枚举命令
private DealType dealtype;
public DrawImg()
{}
public string PublicWorkingDirectory
{
get
{
return WorkingDirectory;
}
set
{
WorkingDirectory = value;
}
}
public string PublicImageName
{
get
{
return ImageName;
}
set
{
ImageName = value;
}
}
public string PublicImageWater
{
get
{
return ImageWater;
}
set //设置了水印图片的话说明是要水印图片效果的
{
dealtype = DealType.WaterImage;
ImageWater = value;
}
}
public string PublicFontString
{
get
{
return FontString;
}
set //设置了水印文字的话说明是要水印文字效果的
{
dealtype = DealType.WaterFont;
FontString = value;
}
}
public void DealImage()
{
IsDouble();
switch( dealtype )
{
case DealType.WaterFont: WriteFont(); break;
case DealType.WaterImage: WriteImg(); break;
case DealType.DoubleDo: WriteFontAndImg(); break;
}
}
private void IsDouble()
{
if(ImageWater+""!="" && FontString+""!="")
{
dealtype = DealType.DoubleDo;
}
}
private void WriteFont()
{
//set a working directory
//string WorkingDirectory = @"C:Watermark_srcWaterPic";
//define a string of text to use as the Copyright message
//string Copyright = "Copyright ?2002 - AP Photo/David Zalubowski";
//create a image object containing the photograph to watermark
Image imgPhoto = Image.FromFile(WorkingDirectory + ImageName);
int phWidth = imgPhoto.Width;
int phHeight = imgPhoto.Height;
//create a Bitmap the Size of the original photograph
Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
//load the Bitmap into a Graphics object
Graphics grPhoto = Graphics.FromImage(bmPhoto);
//------------------------------------------------------------
//Step #1 - Insert Copyright message
//------------------------------------------------------------
//Set the rendering quality for this Graphics object
grPhoto.SmoothingMode = SmoothingMode.AntiAlias;
//Draws the photo Image object at original size to the graphics object.
grPhoto.DrawImage(
imgPhoto, // Photo Image object
new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
0, // x-coordinate of the portion of the source image to draw.
0, // y-coordinate of the portion of the source image to draw.
phWidth, // Width of the portion of the source image to draw.
phHeight, // Height of the portion of the source image to draw.
GraphicsUnit.Pixel); // Units of measure
//-------------------------------------------------------
//to maximize the size of the Copyright message we will
//test multiple Font sizes to determine the largest posible
//font we can use for the width of the Photograph
//define an array of point sizes you would like to consider as possiblities
//-------------------------------------------------------
int[] sizes = new int[]{16,14,12,10,8,6,4};
Font crFont = null;
SizeF crSize = new SizeF();
//Loop through the defined sizes checking the length of the Copyright string
//If its length in pixles is less then the image width choose this Font size.
for (int i=0 ;i<7; i++)
{
//set a Font object to Arial (i)pt, Bold
//crFont = new Font("arial", sizes[i], FontStyle.Bold);
crFont = new Font("arial",sizes[i],FontStyle.Bold);
//Measure the Copyright string in this Font
crSize = grPhoto.MeasureString(FontString, crFont);
if((ushort)crSize.Width < (ushort)phWidth)
break;
}
//Since all photographs will have varying heights, determine a
//position 5% from the bottom of the image
int yPixlesFromBottom = (int)(phHeight *.05);
//Now that we have a point size use the Copyrights string height
//to determine a y-coordinate to draw the string of the photograph
float yPosFromBottom = ((phHeight - yPixlesFromBottom)-(crSize.Height/2));
//Determine its x-coordinate by calculating the center of the width of the image
float xCenterOfImg = (phWidth/2);
//Define the text layout by setting the text alignment to centered
StringFormat StrFormat = new StringFormat();
StrFormat.Alignment = StringAlignment.Center;
//define a Brush which is semi trasparent black (Alpha set to 153)
SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0));
//Draw the Copyright string
grPhoto.DrawString(FontString, //string of text
crFont, //font
semiTransBrush2, //Brush
new PointF(xCenterOfImg+1,yPosFromBottom+1), //Position
StrFormat);
//define a Brush which is semi trasparent white (Alpha set to 153)
SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));
//Draw the Copyright string a second time to create a shadow effect
//Make sure to move this text 1 pixel to the right and down 1 pixel
grPhoto.DrawString(FontString, //string of text
crFont, &nb, sp; //font
semiTransBrush, //Brush
new PointF(xCenterOfImg,yPosFromBottom), //Position
StrFormat);
imgPhoto = bmPhoto;
grPhoto.Dispose();
//save new image to file system.
imgPhoto.Save(WorkingDirectory + ImageName + "_finally.jpg", ImageFormat.Jpeg);
imgPhoto.Dispose();
//Text alignment
}
private void WriteImg()
{
//set a working directory
//string WorkingDirectory = @"C:Watermark_srcWaterPic";
//create a image object containing the photograph to watermark
Image imgPhoto = Image.FromFile(WorkingDirectory + ImageName);
int phWidth = imgPhoto.Width;
int phHeight = imgPhoto.Height;
//create a Bitmap the Size of the original photograph
Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
//load the Bitmap into a Graphics object
Graphics grPhoto = Graphics.FromImage(bmPhoto);
//create a image object containing the watermark
Image imgWatermark = new Bitmap(WorkingDirectory + ImageWater);
int wmWidth = imgWatermark.Width;
int wmHeight = imgWatermark.Height;
//Set the rendering quality for this Graphics object
grPhoto.SmoothingMode = SmoothingMode.AntiAlias;
//Draws the photo Image object at original size to the graphics object.
grPhoto.DrawImage(
imgPhoto, // Photo Image object
new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
0, // x-coordinate of the portion of the source image to draw.
0, // y-coordinate of the portion of the source image to draw.
phWidth, // Width of the portion of the source image to draw.
phHeight, // Height of the portion of the source image to draw.
GraphicsUnit.Pixel); // Units of measure
//------------------------------------------------------------
//Step #2 - Insert Watermark image
//------------------------------------------------------------
//Create a Bitmap based on the previously modified photograph Bitmap
Bitmap bmWatermark = new Bitmap(bmPhoto);
bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
//Load this Bitmap into a new Graphic Object
Graphics grWatermark = Graphics.FromImage(bmWatermark);
//To achieve a transulcent watermark we will apply (2) color
//manipulations by defineing a ImageAttributes object and
//seting (2) of its properties.
ImageAttributes imageAttributes = new ImageAttributes();
//The first step in manipulating the watermark image is to replace
//the background color with one that is trasparent (Alpha=0, R=0, G=0, B=0)
//to do this we will use a Colormap and use this to define a RemapTable
ColorMap colorMap = new ColorMap();
//My watermark was defined with a background of 100% Green this will
//be the color we search for and replace with transparency
colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
ColorMap[] remapTable = {colorMap};
imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
//The second color manipulation is used to change the opacity of the
//watermark. This is done by applying a 5x5 matrix that contains the
//coordinates for the RGBA space. By setting the 3rd row and 3rd column
//to 0.3f we achive a level of opacity
float[][] colorMatrixElements = {
new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f},
new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f},
new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f},
new float[] {0.0f, 0.0f, 0.0f, 0.3f, 0.0f},
new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}};
ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);
imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default,
ColorAdjustType.Bitmap);
//For this example we will place the watermark in the upper right
//hand corner of the photograph. offset down 10 pixels and to the
//left 10 pixles
int xPosOfWm = ((phWidth - wmWidth)-10);
int yPosOfWm = 10;
grWatermark.DrawImage(imgWatermark,
new Rectangle(xPosOfWm,yPosOfWm,wmWidth,wmHeight), //Set the detination Position
0, // x-coordinate of the portion of the source image to draw.
0, // y-coordinate of the portion of the source image to draw.
wmWidth, // Watermark Width
wmHeight, // Watermark Height
GraphicsUnit.Pixel, // Unit of measurment
imageAttributes); //ImageAttributes Object
//Replace the original photgraphs bitmap with the new Bitmap
imgPhoto = bmWatermark;
grPhoto.Dispose();
grWatermark.Dispose();
//save new image to file system.
imgPhoto.Save(WorkingDirectory + ImageName +"_finally.jpg", ImageFormat.Jpeg);
imgPhoto.Dispose();
imgWatermark.Dispose();
}
private void WriteFontAndImg()
{
//create a image object containing the photograph to watermark
Image imgPhoto = Image.FromFile(WorkingDirectory + ImageName);
int phWidth = imgPhoto.Width;
int phHeight = imgPhoto.Height;
//create a Bitmap the Size of the original photograph
Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
//load the Bitmap into a Graphics object
Graphics grPhoto = Graphics.FromImage(bmPhoto);
//create a image object containing the watermark
Image imgWatermark = new Bitmap(WorkingDirectory + ImageWater);
int wmWidth = imgWatermark.Width;
int wmHeight = imgWatermark.Height;
//------------------------------------------------------------
//Step #1 - Insert Copyright message
//------------------------------------------------------------
//Set the rendering quality for this Graphics object
grPhoto.SmoothingMode = SmoothingMode.AntiAlias;
//Draws the photo Image object at original size to the graphics object.
grPhoto.DrawImage(
imgPhoto, // Photo Image object
new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
0, // x-coordinate of the portion of the source image to draw.
0, // y-coordinate of the portion of the source image to draw.
phWidth, // Width of the portion of the source image to draw.
phHeight, // Height of the portion of the source image to draw.
GraphicsUnit.Pixel); // Units of measure
//-------------------------------------------------------
//to maximize the size of the Copyright message we will
//test multiple Font sizes to determine the largest posible
//font we can use for the width of the Photograph
//define an array of point sizes you would like to consider as possiblities
//-------------------------------------------------------
int[] sizes = new int[]{16,14,12,10,8,6,4};
Font crFont = null;
SizeF crSize = new SizeF();
//Loop through the defined sizes checking the length of the Copyright string
//If its length in pixles is less then the image width choose this Font size.
for (int i=0 ;i<7; i++)
{
//set a Font object to Arial (i)pt, Bold
crFont = new Font("arial", sizes[i], FontStyle.Bold);
//Measure the Copyright string in this Font
crSize = grPhoto.MeasureString(FontString, crFont);
if((ushort)crSize.Width < (ushort)phWidth)
break;
}
//Since all photographs will have varying heights, determine a
//position 5% from the bottom of the image
int yPixlesFromBottom = (int)(phHeight *.05);
//Now that we have a point size use the Copyrights string height
//to determine a y-coordinate to draw the string of the photograph
float yPosFromBottom = ((phHeight - yPixlesFromBottom)-(crSize.Height/2));
//Determine its x-coordinate by calculating the center of the width of the image
float xCenterOfImg = (phWidth/2);
//Define the text layout by setting the text alignment to centered
StringFormat StrFormat = new StringFormat();
StrFormat.Alignment = StringAlignment.Center;
//define a Brush which is semi trasparent black (Alpha set to 153)
SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0));
//Draw the Copyright string
grPhoto.DrawString(FontString, //string of text
crFont, //font
semiTransBrush2, //Brush
new PointF(xCenterOfImg+1,yPosFromBottom+1), //Position
StrFormat);
//define a Brush which is semi trasparent white (Alpha set to 153)
SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));
//Draw the Copyright string a second time to create a shadow effect
//Make sure to move this text 1 pixel to the right and down 1 pixel
grPhoto.DrawString(FontString, //string of text
crFont, //font
semiTransBrush, //Brush
new PointF(xCenterOfImg,yPosFromBottom), //Position
StrFormat); //Text alignment
//------------------------------------------------------------
//Step #2 - Insert Watermark image
//------------------------------------------------------------
//Create a Bitmap based on the previously modified photograph Bitmap
Bitmap bmWatermark = new Bitmap(bmPhoto);
bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
//Load this Bitmap into a new Graphic Object
Graphics grWatermark = Graphics.FromImage(bmWatermark);
//To achieve a transulcent watermark we will apply (2) color
//manipulations by defineing a ImageAttributes object and
//seting (2) of its properties.
ImageAttributes imageAttributes = new ImageAttributes();
//The first step in manipulating the watermark image is to replace
//the background color with one that is trasparent (Alpha=0, R=0, G=0, B=0)
//to do this we will use a Colormap and use this to define a RemapTable
ColorMap colorMap = new ColorMap();
//My watermark was defined with a background of 100% Green this will
//be the color we search for and replace with transparency
colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
ColorMap[] remapTable = {colorMap};
imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
//The second color manipulation is used to change the opacity of the
//watermark. This is done by applying a 5x5 matrix that contains the
//coordinates for the RGBA space. By setting the 3rd row and 3rd column
//to 0.3f we achive a level of opacity
float[][] colorMatrixElements = {
new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f},
new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f},
new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f},
new float[] {0.0f, 0.0f, 0.0f, 0.3f, 0.0f},
new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}};
ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);
imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default,
ColorAdjustType.Bitmap);
//For this example we will place the watermark in the upper right
//hand corner of the photograph. offset down 10 pixels and to the
//left 10 pixles
int xPosOfWm = ((phWidth - wmWidth)-10);
int yPosOfWm = 10;
grWatermark.DrawImage(imgWatermark,
new Rectangle(xPosOfWm,yPosOfWm,wmWidth,wmHeight), //Set the detination Position
0, // x-coordinate of the portion of the source image to draw.
0, // y-coordinate of the portion of the source image to draw.
wmWidth, // Watermark Width
wmHeight, // Watermark Height
GraphicsUnit.Pixel, // Unit of measurment
imageAttributes); //ImageAttributes Object
//Replace the original photgraphs bitmap with the new Bitmap
imgPhoto = bmWatermark;
grPhoto.Dispose();
grWatermark.Dispose();
//save new image to file system.
imgPhoto.Save(WorkingDirectory + ImageName +"_finally.jpg", ImageFormat.Jpeg);
imgPhoto.Dispose();
imgWatermark.Dispose();
}
}
//水印图片加水印文字
// ReDrawImg img = new ReDrawImg();
// img .PublicWorkingDirectory = @"C:Watermark_srcWaterPic";
// img .PublicImageName = "watermark_photo.jpg";
// img .PublicImageWater = "watermark.bmp";
// img .PublicFontString = "清清月儿";
// img .DealImage();
//水印文字
ReDrawImg img = new ReDrawImg();
img .PublicWorkingDirectory = @"C:Watermark_srcWaterPic";
img .PublicImageName = "watermark_photo.jpg";
img .PublicFontString = @"清清月儿";
img .DealImage();
//水印图片
// ReDrawImg img = new ReDrawImg();
// img .PublicWorkingDirectory = @"C:Watermark_srcWaterPic";
// img .PublicImageName = "watermark_photo.jpg";
// img .PublicImageWater = "watermark.bmp";
// img .DealImage();
后台代码：
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void bt_upload_Click(object sender, EventArgs e)
{
try
{
if (FileUpload1.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
string filepath = FileUpload1.PostedFile.FileName;
string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
string serverpath1 = Server.MapPath("images/") + filename;
//string serverpath2 = Server.MapPath("images/") + System.DateTime.Now.ToString("yyy-MM-dd-hh-mm-ss") + Session.SessionID + filename;
FileUpload1.PostedFile.SaveAs(serverpath1);
//ImageThumbnail img = new ImageThumbnail(filepath);
//img.ReducedImage(0.4, serverpath2);
DrawImg img = new DrawImg();
img.PublicWorkingDirectory = Server.MapPath("images/");
img.PublicImageName = filename;
img.PublicFontString = "http://blog.csdn.Net/21as.Net";
img.PublicImageWater = "yyy.jpg";
img.DealImage();
this.lb_info.Text = "上传成功！";
}
}
catch (Exception error)
{
this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
}
}
}
1 1.最简单的单文件上传(没花头)
2
3 效果图：
4
5 说明：这是最基本的文件上传，在asp.Net1.x中没有这个FileUpload控件，只有html的上传控件，那时候要把html控件转化为服务器控件，很不好用。其实所有文件上传的美丽效果都是从这个FileUpload控件衍生，第一个例子虽然简单却是根本。
6
7 后台代码：
8 using System;
9 using System.Data;
10 using System.Configuration;
11 using System.Collections;
12 using System.Web;
13 using System.Web.Security;
14 using System.Web.UI;
15 using System.Web.UI.WebControls;
16 using System.Web.UI.WebControls.WebParts;
17 using System.Web.UI.HtmlControls;
18
19 public partial class _Default : System.Web.UI.Page
20 {
21 protected void Page_Load(object sender, EventArgs e)
22 {
23
24 }
25 protected void bt_upload_Click(object sender, EventArgs e)
26 {
27 try
28 {
29 if (FileUpload1.PostedFile.FileName == "")
30 {
31 this.lb_info.Text = "请选择文件！";
32 }
33 else
34 {
35 string filepath = FileUpload1.PostedFile.FileName;
36 string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
37 string serverpath = Server.MapPath("images/") + filename;
38 FileUpload1.PostedFile.SaveAs(serverpath);
39 this.lb_info.Text = "上传成功！";
40 }
41 }
42 catch (Exception ex)
43 {
44 this.lb_info.Text = "上传发生错误！原因是：" + ex.ToString();
45 }
46 }
47 }
48
49 前台代码：
50 <table style=" 343px">
51 <tr>
52 <td style=" 100px">
53 单文件上传</td>
54 <td style=" 100px">
55 </td>
56 </tr>
57 <tr>
58 <td style=" 100px">
59 <asp:FileUpload ID="FileUpload1" runat="server" Width="475px" />
60 </td>
61 <td style=" 100px">
62 <asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="上传" /></td>
63 </tr>
64 <tr>
65 <td style=" 100px; height: 21px;">
66 <asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="183px"></asp:Label></td>
67 <td style=" 100px; height: 21px">
68 </td>
69 </tr>
70 </table>
71
72 2.多文件上传
73
74 效果图：
75
76
77 后台代码：
78 using System;
79 using System.Data;
80 using System.Configuration;
81 using System.Collections;
82 using System.Web;
83 using System.Web.Security;
84 using System.Web.UI;
85 using System.Web.UI.WebControls;
86 using System.Web.UI.WebControls.WebParts;
87 using System.Web.UI.HtmlControls;
88
89 public partial class _Default : System.Web.UI.Page
90 {
91 protected void Page_Load(object sender, EventArgs e)
92 {
93
94 }
95 protected void bt_upload_Click(object sender, EventArgs e)
96 {
97
98 if ((FileUpload1.PostedFile.FileName == "" && FileUpload2.PostedFile.FileName == "")&&FileUpload3.PostedFile.FileName == "")
99 {
100 this.lb_info.Text = "请选择文件！";
101 }
102 else
103 {
104 HttpFileCollection myfiles = Request.Files;
105 for (int i = 0; i < myfiles.Count; i++)
106 {
107 HttpPostedFile mypost = myfiles[i];
108 try
109 {
110 if (mypost.ContentLength > 0)
111 {
112 string filepath = mypost.FileName;
113 string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
114 string serverpath = Server.MapPath("images/") + filename;
115 mypost.SaveAs(serverpath);
116 this.lb_info.Text = "上传成功！";
117 }
118 }
119 catch (Exception error)
120 {
121 this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
122 }
123
124 }
125
126 }
127 }
128
129 }
130
131 前台代码：
132 <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
133
134 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
135
136 <html Xmlns="http://www.w3.org/1999/xhtml" >
137 <head runat="server">
138 <title>多文件上传 清清月儿http://blog.csdn.Net/21as.Net/</title>
139 </head>
140 <body>
141 <form id="form1" runat="server">
142 <div>
143 <table style=" 343px">
144 <tr>
145 <td style=" 100px">
146 多文件上传</td>
147 <td style=" 100px">
148 </td>
149 </tr>
150 <tr>
151 <td style=" 100px">
152 <asp:FileUpload ID="FileUpload1" runat="server" Width="475px" />
153 </td>
154 <td style=" 100px">
155 </td>
156 </tr>
157 <tr>
158 <td style=" 100px">
159 <asp:FileUpload ID="FileUpload2" runat="server" Width="475px" /></td>
160 <td style=" 100px">
161 </td>
162 </tr>
163 <tr>
164 <td style=" 100px">
165 <asp:FileUpload ID="FileUpload3" runat="server" Width="475px" /></td>
166 <td style=" 100px">
167 </td>
168 </tr>
169 <tr>
170 <td style=" 100px">
171 <asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="一起上传" />
172 <asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="183px"></asp:Label></td>
173 <td style=" 100px">
174 </td>
175 </tr>
176 </table>
177
178 </div>
179 </form>
180 </body>
181 </html>
182
183 3.客户端检查上传文件类型(以上传图片为例)
184
185 效果图：
186
187 后台代码和1.最简单的单文件上传一样；
188 前台代码：
189 <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
190
191 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
192
193 <html Xmlns="http://www.w3.org/1999/xhtml" >
194 <head runat="server">
195 <title>清清月儿 .Net/21as.Nethttp://blog.csdn.Net/21as.Net</title>
196 <script language="Javascript">
197 function Check_FileType()
198 {
199 var str=document.getElementById("FileUpload1").value;
200 var pos = str.lastIndexOf(".");
201 var lastname = str.substring(pos,str.length)
202 if (lastname.toLowerCase()!=".jpg" && lastname.toLowerCase()!=".gif")
203 {
204 alert("您上传的文件类型为"+lastname+"，图片必须为.jpg,.gif类型");
205 return false;
206 }
207 else
208 {
209 return true;
210 }
211 }
212 </script>
213
214 </head>
215 <body>
216 <form id="form1" runat="server">
217 <div>
218 <table style=" 343px">
219 <tr>
220 <td style=" 104px">
221 文件上传判断</td>
222 <td style=" 100px">
223 </td>
224 </tr>
225 <tr>
226 <td style=" 104px">
227 <asp:FileUpload ID="FileUpload1" runat="server" Width="400px" />
228 </td>
229 <td style=" 100px">
230 <asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="上传" OnClientClick="return Check_FileType()"/></td>
231 </tr>
232 <tr>
233 <td style=" 104px; height: 21px;">
234 <asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="183px"></asp:Label></td>
235 <td style=" 100px; height: 21px">
236 </td>
237 </tr>
238 </table>
239
240 </div>
241 </form>
242 </body>
243 </html>
244 说明：点击上传时先触发客户端事件Check_FileType；
245
246 4.服务器端检查上传文件类型(以上传图片为例)
247
248 效果图：
249
250
251 后台代码：
252 using System;
253 using System.Data;
254 using System.Configuration;
255 using System.Collections;
256 using System.Web;
257 using System.Web.Security;
258 using System.Web.UI;
259 using System.Web.UI.WebControls;
260 using System.Web.UI.WebControls.WebParts;
261 using System.Web.UI.HtmlControls;
262
263 public partial class _Default : System.Web.UI.Page
264 {
265 protected void Page_Load(object sender, EventArgs e)
266 {
267
268 }
269 protected void bt_upload_Click(object sender, EventArgs e)
270 {
271 try
272 {
273 if (FileUpload1.PostedFile.FileName == "")
274 {
275 this.lb_info.Text = "请选择文件！";
276 }
277 else
278 {
279 string filepath = FileUpload1.PostedFile.FileName;
280 if (IsAllowedExtension(FileUpload1) == true)
281 {
282
283 string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
284 string serverpath = Server.MapPath("images/") + filename;
285 FileUpload1.PostedFile.SaveAs(serverpath);
286 this.lb_info.Text = "上传成功！";
287 }
288 else
289 {
290 this.lb_info.Text = "请上传图片";
291 }
292 }
293 }
294 catch (Exception error)
295 {
296 this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
297 }
298 }
299 public static bool IsAllowedExtension(FileUpload hifile)
300 {
301 string strOldFilePath = "", strExtension = "";
302 string[] arrExtension = { ".gif", ".jpg", ".jpeg", ".bmp", ".png" };
303 if (hifile.PostedFile.FileName != string.Empty)
304 {
305 strOldFilePath = hifile.PostedFile.FileName;
306 strExtension = strOldFilePath.Substring(strOldFilePath.LastIndexOf("."));
307 for (int i = 0; i < arrExtension.Length; i++)
308 {
309 if (strExtension.Equals(arrExtension[i]))
310 {
311 return true;
312 }
313 }
314 }
315 return false;
316 }
317
318 }
319
320
321 5.服务器端检查上传文件类型(可以检测真正文件名)
322 其实方法4并不好，因为用户可以把XXX.txt伪装为XXX.jpg。
323
324 效果图：
325
326
327 后台代码：
328 using System;
329 using System.Data;
330 using System.Configuration;
331 using System.Collections;
332 using System.Web;
333 using System.Web.Security;
334 using System.Web.UI;
335 using System.Web.UI.WebControls;
336 using System.Web.UI.WebControls.WebParts;
337 using System.Web.UI.HtmlControls;
338
339 public partial class _Default : System.Web.UI.Page
340 {
341 //清清月儿 http://blog.csdn.Net/21as.Net
342 protected void Page_Load(object sender, EventArgs e)
343 {
344
345 }
346 protected void bt_upload_Click(object sender, EventArgs e)
347 {
348 try
349 {
350 if (FileUpload1.PostedFile.FileName == "")
351 {
352 this.lb_info.Text = "请选择文件！";
353 }
354 else
355 {
356 string filepath = FileUpload1.PostedFile.FileName;
357 if (IsAllowedExtension(FileUpload1) == true)
358 {
359 string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
360 string serverpath = Server.MapPath("images/") + filename;
361 FileUpload1.PostedFile.SaveAs(serverpath);
362 this.lb_info.Text = "上传成功！";
363 }
364 else
365 {
366 this.lb_info.Text = "请上传图片";
367 }
368 }
369 }
370 catch (Exception error)
371 {
372 this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
373 }
374 }
375 public static bool IsAllowedExtension(FileUpload hifile)
376 {
377 System.IO.FileStream fs = new System.IO.FileStream(hifile.PostedFile.FileName, System.IO.FileMode.Open, System.IO.FileAccess.Read);
378 System.IO.BinaryReader r = new System.IO.BinaryReader(fs);
379 string fileclass = "";
380 byte buffer;
381 try
382 {
383 buffer = r.ReadByte();
384 fileclass = buffer.ToString();
385 buffer = r.ReadByte();
386 fileclass += buffer.ToString();
387
388 }
389 catch
390 {
391
392 }
393 r.Close();
394 fs.Close();
395 if (fileclass == "255216" || fileclass == "7173")//说明255216是jpg;7173是gif;6677是BMP,13780是PNG;7790是exe,8297是rar
396 {
397 return true;
398 }
399 else
400 {
401 return false;
402 }
403
404 }
405
406 }
407
408 6.上传文件文件名唯一性处理(时间戳+SessionID)
409
410 效果图：
411
412 说明：年月日时分秒+临时session+原文件名 如果大家怕还会重复可以加GUID
413 后台代码：
414
415
416 try
417 {
418 if (FileUpload1.PostedFile.FileName == "")
419 {
420 this.lb_info.Text = "请选择文件！";
421 }
422 else
423 {
424 string filepath = FileUpload1.PostedFile.FileName;
425 string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
426 string serverpath = Server.MapPath("images/") + System.DateTime.Now.ToString("yyy-MM-dd-hh-mm-ss") + Session.SessionID + filename;
427 FileUpload1.PostedFile.SaveAs(serverpath);
428 this.lb_info.Text = "上传成功！";
429 }
430 }
431 catch (Exception error)
432 {
433 this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
434 }
435
436 注：GUID的方法：Guid myGuid=Guid.NewGuid();
437
438 7.上传图片生成等比例缩略图
439
440 效果图：
441
442
443 缩略图代码：
444 ImageThumbnail.cs
445 using System;
446 using System.IO;
447 using System.Drawing;
448 using System.Drawing.Imaging;
449
450 public class ImageThumbnail
451 {
452 public Image ResourceImage;
453 private int ImageWidth;
454 private int ImageHeight;
455 public string ErrorMessage;
456
457 public ImageThumbnail(string ImageFileName)
458 {
459 ResourceImage = Image.FromFile(ImageFileName);
460 ErrorMessage = "";
461 }
462
463 public bool ThumbnailCallback()
464 {
465 return false;
466 }
467
468
469 // 方法1，按大小
470 public bool ReducedImage(int Width, int Height, string targetFilePath)
471 {
472 try
473 {
474 Image ReducedImage;
475 Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
476 ReducedImage = ResourceImage.GetThumbnailImage(Width, Height, callb, IntPtr.Zero);
477 ReducedImage.Save(@targetFilePath, ImageFormat.Jpeg);
478 ReducedImage.Dispose();
479 return true;
480 }
481 catch (Exception e)
482 {
483 ErrorMessage = e.Message;
484 return false;
485 }
486 }
487
488
489 // 方法2，按百分比 缩小60% Percent为0.6 targetFilePath为目标路径
490 public bool ReducedImage(double Percent, string targetFilePath)
491 {
492 try
493 {
494 Image ReducedImage;
495 Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
496 ImageWidth = Convert.ToInt32(ResourceImage.Width * Percent);
497 ImageHeight = (ResourceImage.Height)*ImageWidth/ ResourceImage.Width;//等比例缩放
498 ReducedImage = ResourceImage.GetThumbnailImage(ImageWidth, ImageHeight, callb, IntPtr.Zero);
499 ReducedImage.Save(@targetFilePath, ImageFormat.Jpeg);
500 ReducedImage.Dispose();
501 return true;
502 }
503 catch (Exception e)
504 {
505 ErrorMessage = e.Message;
506 return false;
507 }
508 }
509
510
511 }
512
513 后台代码：
514 using System;
515 using System.Data;
516 using System.Configuration;
517 using System.Collections;
518 using System.Web;
519 using System.Web.Security;
520 using System.Web.UI;
521 using System.Web.UI.WebControls;
522 using System.Web.UI.WebControls.WebParts;
523 using System.Web.UI.HtmlControls;
524 public partial class _Default : System.Web.UI.Page
525 {
526
527 protected void Page_Load(object sender, EventArgs e)
528 {
529
530 }
531 protected void bt_upload_Click(object sender, EventArgs e)
532 {
533 try
534 {
535 if (FileUpload1.PostedFile.FileName == "")
536 {
537 this.lb_info.Text = "请选择文件！";
538 }
539 else
540 {
541 string filepath = FileUpload1.PostedFile.FileName;
542 string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
543 string serverpath1 = Server.MapPath("images/") + filename;
544 string serverpath2 = Server.MapPath("images/") + System.DateTime.Now.ToString("yyy-MM-dd-hh-mm-ss") + Session.SessionID + filename;
545 FileUpload1.PostedFile.SaveAs(serverpath1);
546 ImageThumbnail img = new ImageThumbnail(filepath);
547 img.ReducedImage(0.4, serverpath2);//0.4表示缩小40%
548 this.lb_info.Text = "上传成功！";
549 }
550 }
551 catch (Exception error)
552 {
553 this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
554 }
555 }
556
557
558 }
559
560 8.上传图片加水印(文字水印，图片水印，文字+图片水印)
561
562 效果图：
563 原图
564
565 水印
566
567 给图片加水印以后（注意右上角+正下方）
568
569
570 代码：
571 DrawImg.cs 出自http://www.codeproject.com/csharp/watermark.asp
572 using System;
573 using System.Drawing;
574 using System.Drawing.Imaging;
575 using System.Drawing.Drawing2D;
576 public class DrawImg
577 {
578 private string WorkingDirectory = string.Empty ; //路径
579 private string ImageName = string.Empty; //被处理的图片
580 private string ImageWater = string.Empty; //水印图片
581 private string FontString = string.Empty; //水印文字
582
583
584 enum DealType{NONE,WaterImage,WaterFont,DoubleDo}; //枚举命令
585
586 private DealType dealtype;
587
588
589 public DrawImg()
590 {}
591
592 public string PublicWorkingDirectory
593 {
594 get
595 {
596 return WorkingDirectory;
597 }
598 set
599 {
600 WorkingDirectory = value;
601 }
602 }
603
604 public string PublicImageName
605 {
606 get
607 {
608 return ImageName;
609 }
610 set
611 {
612 ImageName = value;
613 }
614 }
615
616
617 public string PublicImageWater
618 {
619 get
620 {
621 return ImageWater;
622 }
623 set //设置了水印图片的话说明是要水印图片效果的
624 {
625 dealtype = DealType.WaterImage;
626 ImageWater = value;
627 }
628 }
629
630 public string PublicFontString
631 {
632 get
633 {
634 return FontString;
635 }
636 set //设置了水印文字的话说明是要水印文字效果的
637 {
638 dealtype = DealType.WaterFont;
639 FontString = value;
640 }
641 }
642
643
644
645 public void DealImage()
646 {
647 IsDouble();
648
649 switch( dealtype )
650 {
651 case DealType.WaterFont: WriteFont(); break;
652 case DealType.WaterImage: WriteImg(); break;
653 case DealType.DoubleDo: WriteFontAndImg(); break;
654 }
655
656 }
657
658 private void IsDouble()
659 {
660 if(ImageWater+""!="" && FontString+""!="")
661 {
662 dealtype = DealType.DoubleDo;
663 }
664 }
665
666 private void WriteFont()
667 {
668 //set a working directory
669 //string WorkingDirectory = @"C:Watermark_srcWaterPic";
670
671 //define a string of text to use as the Copyright message
672 //string Copyright = "Copyright ?2002 - AP Photo/David Zalubowski";
673
674 //create a image object containing the photograph to watermark
675 Image imgPhoto = Image.FromFile(WorkingDirectory + ImageName);
676 int phWidth = imgPhoto.Width;
677 int phHeight = imgPhoto.Height;
678
679 //create a Bitmap the Size of the original photograph
680 Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
681
682 bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
683
684 //load the Bitmap into a Graphics object
685 Graphics grPhoto = Graphics.FromImage(bmPhoto);
686
687 //------------------------------------------------------------
688 //Step #1 - Insert Copyright message
689 //------------------------------------------------------------
690
691 //Set the rendering quality for this Graphics object
692 grPhoto.SmoothingMode = SmoothingMode.AntiAlias;
693
694 //Draws the photo Image object at original size to the graphics object.
695 grPhoto.DrawImage(
696 imgPhoto, // Photo Image object
697 new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
698 0, // x-coordinate of the portion of the source image to draw.
699 0, // y-coordinate of the portion of the source image to draw.
700 phWidth, // Width of the portion of the source image to draw.
701 phHeight, // Height of the portion of the source image to draw.
702 GraphicsUnit.Pixel); // Units of measure
703
704 //-------------------------------------------------------
705 //to maximize the size of the Copyright message we will
706 //test multiple Font sizes to determine the largest posible
707 //font we can use for the width of the Photograph
708 //define an array of point sizes you would like to consider as possiblities
709 //-------------------------------------------------------
710 int[] sizes = new int[]{16,14,12,10,8,6,4};
711
712 Font crFont = null;
713 SizeF crSize = new SizeF();
714
715 //Loop through the defined sizes checking the length of the Copyright string
716 //If its length in pixles is less then the image width choose this Font size.
717 for (int i=0 ;i<7; i++)
718 {
719 //set a Font object to Arial (i)pt, Bold
720 //crFont = new Font("arial", sizes[i], FontStyle.Bold);
721
722 crFont = new Font("arial",sizes[i],FontStyle.Bold);
723
724 //Measure the Copyright string in this Font
725 crSize = grPhoto.MeasureString(FontString, crFont);
726
727 if((ushort)crSize.Width < (ushort)phWidth)
728 break;
729 }
730
731 //Since all photographs will have varying heights, determine a
732 //position 5% from the bottom of the image
733 int yPixlesFromBottom = (int)(phHeight *.05);
734
735 //Now that we have a point size use the Copyrights string height
736 //to determine a y-coordinate to draw the string of the photograph
737 float yPosFromBottom = ((phHeight - yPixlesFromBottom)-(crSize.Height/2));
738
739 //Determine its x-coordinate by calculating the center of the width of the image
740 float xCenterOfImg = (phWidth/2);
741
742 //Define the text layout by setting the text alignment to centered
743 StringFormat StrFormat = new StringFormat();
744 StrFormat.Alignment = StringAlignment.Center;
745
746 //define a Brush which is semi trasparent black (Alpha set to 153)
747 SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0));
748
749 //Draw the Copyright string
750 grPhoto.DrawString(FontString, //string of text
751 crFont, //font
752 semiTransBrush2, //Brush
753 new PointF(xCenterOfImg+1,yPosFromBottom+1), //Position
754 StrFormat);
755
756 //define a Brush which is semi trasparent white (Alpha set to 153)
757 SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));
758
759 //Draw the Copyright string a second time to create a shadow effect
760 //Make sure to move this text 1 pixel to the right and down 1 pixel
761 grPhoto.DrawString(FontString, //string of text
762 crFont, &nb, sp; //font
763 semiTransBrush, //Brush
764 new PointF(xCenterOfImg,yPosFromBottom), //Position
765 StrFormat);
766
767 imgPhoto = bmPhoto;
768 grPhoto.Dispose();
769
770 //save new image to file system.
771 imgPhoto.Save(WorkingDirectory + ImageName + "_finally.jpg", ImageFormat.Jpeg);
772 imgPhoto.Dispose();
773
774 //Text alignment
775 }
776
777
778 private void WriteImg()
779 {
780 //set a working directory
781 //string WorkingDirectory = @"C:Watermark_srcWaterPic";
782
783 //create a image object containing the photograph to watermark
784 Image imgPhoto = Image.FromFile(WorkingDirectory + ImageName);
785 int phWidth = imgPhoto.Width;
786 int phHeight = imgPhoto.Height;
787
788 //create a Bitmap the Size of the original photograph
789 Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
790
791 bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
792
793 //load the Bitmap into a Graphics object
794 Graphics grPhoto = Graphics.FromImage(bmPhoto);
795
796 //create a image object containing the watermark
797 Image imgWatermark = new Bitmap(WorkingDirectory + ImageWater);
798 int wmWidth = imgWatermark.Width;
799 int wmHeight = imgWatermark.Height;
800
801 //Set the rendering quality for this Graphics object
802 grPhoto.SmoothingMode = SmoothingMode.AntiAlias;
803
804 //Draws the photo Image object at original size to the graphics object.
805 grPhoto.DrawImage(
806 imgPhoto, // Photo Image object
807 new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
808 0, // x-coordinate of the portion of the source image to draw.
809 0, // y-coordinate of the portion of the source image to draw.
810 phWidth, // Width of the portion of the source image to draw.
811 phHeight, // Height of the portion of the source image to draw.
812 GraphicsUnit.Pixel); // Units of measure
813
814
815 //------------------------------------------------------------
816 //Step #2 - Insert Watermark image
817 //------------------------------------------------------------
818
819 //Create a Bitmap based on the previously modified photograph Bitmap
820 Bitmap bmWatermark = new Bitmap(bmPhoto);
821 bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
822 //Load this Bitmap into a new Graphic Object
823 Graphics grWatermark = Graphics.FromImage(bmWatermark);
824
825 //To achieve a transulcent watermark we will apply (2) color
826 //manipulations by defineing a ImageAttributes object and
827 //seting (2) of its properties.
828 ImageAttributes imageAttributes = new ImageAttributes();
829
830 //The first step in manipulating the watermark image is to replace
831 //the background color with one that is trasparent (Alpha=0, R=0, G=0, B=0)
832 //to do this we will use a Colormap and use this to define a RemapTable
833 ColorMap colorMap = new ColorMap();
834
835 //My watermark was defined with a background of 100% Green this will
836 //be the color we search for and replace with transparency
837 colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
838 colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
839
840 ColorMap[] remapTable = {colorMap};
841
842 imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
843
844 //The second color manipulation is used to change the opacity of the
845 //watermark. This is done by applying a 5x5 matrix that contains the
846 //coordinates for the RGBA space. By setting the 3rd row and 3rd column
847 //to 0.3f we achive a level of opacity
848 float[][] colorMatrixElements = {
849 new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f},
850 new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f},
851 new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f},
852 new float[] {0.0f, 0.0f, 0.0f, 0.3f, 0.0f},
853 new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}};
854 ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);
855
856 imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default,
857 ColorAdjustType.Bitmap);
858
859 //For this example we will place the watermark in the upper right
860 //hand corner of the photograph. offset down 10 pixels and to the
861 //left 10 pixles
862
863 int xPosOfWm = ((phWidth - wmWidth)-10);
864 int yPosOfWm = 10;
865
866 grWatermark.DrawImage(imgWatermark,
867 new Rectangle(xPosOfWm,yPosOfWm,wmWidth,wmHeight), //Set the detination Position
868 0, // x-coordinate of the portion of the source image to draw.
869 0, // y-coordinate of the portion of the source image to draw.
870 wmWidth, // Watermark Width
871 wmHeight, // Watermark Height
872 GraphicsUnit.Pixel, // Unit of measurment
873 imageAttributes); //ImageAttributes Object
874
875 //Replace the original photgraphs bitmap with the new Bitmap
876 imgPhoto = bmWatermark;
877 grPhoto.Dispose();
878 grWatermark.Dispose();
879
880 //save new image to file system.
881 imgPhoto.Save(WorkingDirectory + ImageName +"_finally.jpg", ImageFormat.Jpeg);
882 imgPhoto.Dispose();
883 imgWatermark.Dispose();
884
885 }
886
887
888 private void WriteFontAndImg()
889 {
890
891 //create a image object containing the photograph to watermark
892 Image imgPhoto = Image.FromFile(WorkingDirectory + ImageName);
893 int phWidth = imgPhoto.Width;
894 int phHeight = imgPhoto.Height;
895
896 //create a Bitmap the Size of the original photograph
897 Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
898
899 bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
900
901 //load the Bitmap into a Graphics object
902 Graphics grPhoto = Graphics.FromImage(bmPhoto);
903
904 //create a image object containing the watermark
905 Image imgWatermark = new Bitmap(WorkingDirectory + ImageWater);
906 int wmWidth = imgWatermark.Width;
907 int wmHeight = imgWatermark.Height;
908
909 //------------------------------------------------------------
910 //Step #1 - Insert Copyright message
911 //------------------------------------------------------------
912
913 //Set the rendering quality for this Graphics object
914 grPhoto.SmoothingMode = SmoothingMode.AntiAlias;
915
916 //Draws the photo Image object at original size to the graphics object.
917 grPhoto.DrawImage(
918 imgPhoto, // Photo Image object
919 new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
920 0, // x-coordinate of the portion of the source image to draw.
921 0, // y-coordinate of the portion of the source image to draw.
922 phWidth, // Width of the portion of the source image to draw.
923 phHeight, // Height of the portion of the source image to draw.
924 GraphicsUnit.Pixel); // Units of measure
925
926 //-------------------------------------------------------
927 //to maximize the size of the Copyright message we will
928 //test multiple Font sizes to determine the largest posible
929 //font we can use for the width of the Photograph
930 //define an array of point sizes you would like to consider as possiblities
931 //-------------------------------------------------------
932 int[] sizes = new int[]{16,14,12,10,8,6,4};
933
934 Font crFont = null;
935 SizeF crSize = new SizeF();
936
937 //Loop through the defined sizes checking the length of the Copyright string
938 //If its length in pixles is less then the image width choose this Font size.
939 for (int i=0 ;i<7; i++)
940 {
941 //set a Font object to Arial (i)pt, Bold
942 crFont = new Font("arial", sizes[i], FontStyle.Bold);
943 //Measure the Copyright string in this Font
944 crSize = grPhoto.MeasureString(FontString, crFont);
945
946 if((ushort)crSize.Width < (ushort)phWidth)
947 break;
948 }
949
950 //Since all photographs will have varying heights, determine a
951 //position 5% from the bottom of the image
952 int yPixlesFromBottom = (int)(phHeight *.05);
953
954 //Now that we have a point size use the Copyrights string height
955 //to determine a y-coordinate to draw the string of the photograph
956 float yPosFromBottom = ((phHeight - yPixlesFromBottom)-(crSize.Height/2));
957
958 //Determine its x-coordinate by calculating the center of the width of the image
959 float xCenterOfImg = (phWidth/2);
960
961 //Define the text layout by setting the text alignment to centered
962 StringFormat StrFormat = new StringFormat();
963 StrFormat.Alignment = StringAlignment.Center;
964
965 //define a Brush which is semi trasparent black (Alpha set to 153)
966 SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0));
967
968 //Draw the Copyright string
969 grPhoto.DrawString(FontString, //string of text
970 crFont, //font
971 semiTransBrush2, //Brush
972 new PointF(xCenterOfImg+1,yPosFromBottom+1), //Position
973 StrFormat);
974
975 //define a Brush which is semi trasparent white (Alpha set to 153)
976 SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));
977
978 //Draw the Copyright string a second time to create a shadow effect
979 //Make sure to move this text 1 pixel to the right and down 1 pixel
980 grPhoto.DrawString(FontString, //string of text
981 crFont, //font
982 semiTransBrush, //Brush
983 new PointF(xCenterOfImg,yPosFromBottom), //Position
984 StrFormat); //Text alignment
985
986
987
988 //------------------------------------------------------------
989 //Step #2 - Insert Watermark image
990 //------------------------------------------------------------
991
992 //Create a Bitmap based on the previously modified photograph Bitmap
993 Bitmap bmWatermark = new Bitmap(bmPhoto);
994 bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
995 //Load this Bitmap into a new Graphic Object
996 Graphics grWatermark = Graphics.FromImage(bmWatermark);
997
998 //To achieve a transulcent watermark we will apply (2) color
999 //manipulations by defineing a ImageAttributes object and
1000 //seting (2) of its properties.
1001 ImageAttributes imageAttributes = new ImageAttributes();
1002
1003 //The first step in manipulating the watermark image is to replace
1004 //the background color with one that is trasparent (Alpha=0, R=0, G=0, B=0)
1005 //to do this we will use a Colormap and use this to define a RemapTable
1006 ColorMap colorMap = new ColorMap();
1007
1008 //My watermark was defined with a background of 100% Green this will
1009 //be the color we search for and replace with transparency
1010 colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
1011 colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
1012
1013 ColorMap[] remapTable = {colorMap};
1014
1015 imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
1016
1017 //The second color manipulation is used to change the opacity of the
1018 //watermark. This is done by applying a 5x5 matrix that contains the
1019 //coordinates for the RGBA space. By setting the 3rd row and 3rd column
1020 //to 0.3f we achive a level of opacity
1021 float[][] colorMatrixElements = {
1022 new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f},
1023 new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f},
1024 new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f},
1025 new float[] {0.0f, 0.0f, 0.0f, 0.3f, 0.0f},
1026 new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}};
1027 ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);
1028
1029 imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default,
1030 ColorAdjustType.Bitmap);
1031
1032 //For this example we will place the watermark in the upper right
1033 //hand corner of the photograph. offset down 10 pixels and to the
1034 //left 10 pixles
1035
1036 int xPosOfWm = ((phWidth - wmWidth)-10);
1037 int yPosOfWm = 10;
1038
1039 grWatermark.DrawImage(imgWatermark,
1040 new Rectangle(xPosOfWm,yPosOfWm,wmWidth,wmHeight), //Set the detination Position
1041 0, // x-coordinate of the portion of the source image to draw.
1042 0, // y-coordinate of the portion of the source image to draw.
1043 wmWidth, // Watermark Width
1044 wmHeight, // Watermark Height
1045 GraphicsUnit.Pixel, // Unit of measurment
1046 imageAttributes); //ImageAttributes Object
1047
1048 //Replace the original photgraphs bitmap with the new Bitmap
1049 imgPhoto = bmWatermark;
1050 grPhoto.Dispose();
1051 grWatermark.Dispose();
1052
1053 //save new image to file system.
1054 imgPhoto.Save(WorkingDirectory + ImageName +"_finally.jpg", ImageFormat.Jpeg);
1055 imgPhoto.Dispose();
1056 imgWatermark.Dispose();
1057
1058
1059 }
1060 }
1061
1062
1063 //水印图片加水印文字
1064 // ReDrawImg img = new ReDrawImg();
1065 // img .PublicWorkingDirectory = @"C:Watermark_srcWaterPic";
1066 // img .PublicImageName = "watermark_photo.jpg";
1067 // img .PublicImageWater = "watermark.bmp";
1068 // img .PublicFontString = "清清月儿";
1069 // img .DealImage();
1070
1071 //水印文字
1072 ReDrawImg img = new ReDrawImg();
1073 img .PublicWorkingDirectory = @"C:Watermark_srcWaterPic";
1074 img .PublicImageName = "watermark_photo.jpg";
1075 img .PublicFontString = @"清清月儿";
1076 img .DealImage();
1077
1078
1079 //水印图片
1080 // ReDrawImg img = new ReDrawImg();
1081 // img .PublicWorkingDirectory = @"C:Watermark_srcWaterPic";
1082 // img .PublicImageName = "watermark_photo.jpg";
1083 // img .PublicImageWater = "watermark.bmp";
1084 // img .DealImage();
1085
1086
1087 后台代码：
1088
1089 using System;
1090 using System.Data;
1091 using System.Configuration;
1092 using System.Collections;
1093 using System.Web;
1094 using System.Web.Security;
1095 using System.Web.UI;
1096 using System.Web.UI.WebControls;
1097 using System.Web.UI.WebControls.WebParts;
1098 using System.Web.UI.HtmlControls;
1099 public partial class _Default : System.Web.UI.Page
1100 {
1101
1102 protected void Page_Load(object sender, EventArgs e)
1103 {
1104
1105 }
1106 protected void bt_upload_Click(object sender, EventArgs e)
1107 {
1108 try
1109 {
1110 if (FileUpload1.PostedFile.FileName == "")
1111 {
1112 this.lb_info.Text = "请选择文件！";
1113 }
1114 else
1115 {
1116 string filepath = FileUpload1.PostedFile.FileName;
1117 string filename = filepath.Substring(filepath.LastIndexOf("\") + 1);
1118 string serverpath1 = Server.MapPath("images/") + filename;
1119 //string serverpath2 = Server.MapPath("images/") + System.DateTime.Now.ToString("yyy-MM-dd-hh-mm-ss") + Session.SessionID + filename;
1120 FileUpload1.PostedFile.SaveAs(serverpath1);
1121 //ImageThumbnail img = new ImageThumbnail(filepath);
1122 //img.ReducedImage(0.4, serverpath2);
1123 DrawImg img = new DrawImg();
1124 img.PublicWorkingDirectory = Server.MapPath("images/");
1125 img.PublicImageName = filename;
1126 img.PublicFontString = "http://blog.csdn.Net/21as.Net";
1127 img.PublicImageWater = "yyy.jpg";
1128 img.DealImage();
1129 this.lb_info.Text = "上传成功！";
1130 }
1131 }
1132 catch (Exception error)
1133 {
1134 this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
1135 }
1136 }
1137 }
1138