使用ASP.NET上传图片汇总

zoukankan html css js c++ java

使用ASP.NET上传图片汇总

1 使用标准HTML来进行图片上传

前台代码：

<body>
    <form id="form1" runat="server">
    <div>
        <table>
            <tr>
                <td colspan="2" style="height: 21px" >
                    使用标准HTML来进行图片上传</td>
            </tr>
            <tr>
                <td style=" 400px">
                    <input id="InputFile" style=" 399px" type="file" runat="server" /></td>
                <td style=" 80px">
                    <asp:Button ID="UploadButton" runat="server" Text="上传图片" OnClick="UploadButton_Click" /></td>
            </tr>
            <tr>
                <td colspan="2" >
                    <asp:Label ID="Lb_Info" runat="server" ForeColor="Red"></asp:Label></td>
            </tr>
        </table>
    </div>
    </form>
</body>
后台代码：

using System;
using System.Data;
using System.Configuration;
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 UploadButton_Click(object sender, EventArgs e)
    {
        string uploadName = InputFile.Value;//获取待上传图片的完整路径，包括文件名
        //string uploadName = InputFile.PostedFile.FileName;
        string pictureName = "";//上传后的图片名，以当前时间为文件名，确保文件名没有重复
        if (InputFile.Value != "")
        {
            int idx = uploadName.LastIndexOf(".");
            string suffix = uploadName.Substring(idx);//获得上传的图片的后缀名
            pictureName = DateTime.Now.Ticks.ToString() + suffix;
        }
        try
        {
            if (uploadName != "")
            {
                string path = Server.MapPath("~/images/");
                InputFile.PostedFile.SaveAs(path + pictureName);
            }
        }
        catch (Exception ex)
        {
            Response.Write(ex);
        }
    }
}

2 单文件上传

        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。

前台代码：

<body>
    <form id="form1" runat="server">
    <div>
        <table style=" 90%">
            <tr>
                <td style=" 159px" colspan=2>
                    <strong><span style="font-size: 10pt">最简单的单文件上传</span></strong></td>
            </tr>
            <tr>
                <td style=" 600px">
                    <asp:FileUpload ID="FileUpload1" runat="server" Width="600px" /></td>
                <td align=left>
                    <asp:Button ID="FileUpload_Button" runat="server" Text="上传图片" OnClick="FileUpload_Button_Click" /></td>
            </tr>
            <tr>
                <td colspan=2>
                    <asp:Label ID="Upload_info" runat="server" ForeColor="Red" Width="767px"></asp:Label></td>
            </tr>
        </table>
    </div>
    </form>
</body>
后台代码：

using System;
using System.Data;
using System.Configuration;
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 FileUpload_Button_Click(object sender, EventArgs e)
    {
        try
        {
            if (FileUpload1.PostedFile.FileName == "")
            //if (FileUpload1.FileName == "")
            //if (!FileUpload1.HasFile)     //获取一个值，该值指示 System.Web.UI.WebControls.FileUpload 控件是否包含文件。包含文件，则为 true；否则为 false。
            {
                this.Upload_info.Text = "请选择上传文件！";
            }
            else
            {
                string filepath = FileUpload1.PostedFile.FileName; //得到的是文件的完整路径,包括文件名，如：C:\Documents and Settings\Administrator\My Documents\My Pictures\20022775_m.jpg
                //string filepath = FileUpload1.FileName;               //得到上传的文件名20022775_m.jpg
                string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);//20022775_m.jpg
                string serverpath = Server.MapPath("~/images/") + filename;//取得文件在服务器上保存的位置C:\Inetpub\wwwroot\WebSite1\images\20022775_m.jpg
                FileUpload1.PostedFile.SaveAs(serverpath);//将上传的文件另存为
                this.Upload_info.Text = "上传成功！";
            }
        }
        catch (Exception ex)
        {
            this.Upload_info.Text = "上传发生错误！原因是：" + ex.ToString();
        }
    }
}

3 多文件上传

前台代码：

<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="448px"></asp:Label></td>
                <td style=" 100px">
                </td>
            </tr>
        </table>
    </div>
    </form>
</body>
后台代码：

using System;
using System.Data;
using System.Configuration;
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;//C:\Documents and Settings\Administrator\My Documents\My Pictures\20022775_m.jpg
                        string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);//20022775_m.jpg
                        string serverpath = Server.MapPath("~/images/") + filename;//C:\Inetpub\wwwroot\WebSite2\images\20022775_m.jpg
                        mypost.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：" + ex.Message.ToString();
                }
            }
        }
    }
}

4 客户端检查上传文件类型(以上传图片为例)

<%@ 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>客户端检查上传文件类型</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>
            <tr>
                <td colspan="2">
                    客户端检查上传文件类型</td>
            </tr>
            <tr>
                <td style=" 444px">
                    <asp:FileUpload ID="FileUpload1" runat="server" Width="432px" /></td>
                <td style=" 80px">
                    <asp:Button ID="bt_upload" runat="server" Text="上传图片" OnClick="bt_upload_Click" OnClientClick="return Check_FileType()" /></td>
            </tr>
            <tr>
                <td colspan="2" style="height: 21px">
                    <asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="515px"></asp:Label></td>
            </tr>
        </table>
    </div>
    </form>
</body>
</html>
注意：点击上传时先触发客户端事件OnClientClick="return Check_FileType()"

using System;
using System.Data;
using System.Configuration;
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))
                //{
                //    this.lb_info.Text = "上传文件格式不正确！";
                //}
                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 ex)
        {
            this.lb_info.Text = "上传发生错误！原因：" + ex.ToString();
        }
    }
    private static bool IsAllowedExtension(FileUpload upfile)
    {
        string strOldFilePath = "";
        string strExtension="";
        string[] arrExtension ={ ".gif", ".jpg", ".bmp", ".png" };
        if (upfile.PostedFile.FileName != string.Empty)
        {
            strOldFilePath = upfile.PostedFile.FileName;//获得文件的完整路径名
            strExtension = strOldFilePath.Substring(strOldFilePath.LastIndexOf("."));//获得文件的扩展名，如：.jpg
            for (int i = 0; i < arrExtension.Length; i++)
            {
                if (strExtension.Equals(arrExtension[i]))
                {
                    return true;
                }
            }
        }
        return false;
    }
}
注意：若去掉客户端的脚本和客户端事件OnClientClick="return Check_FileType()"，在后台代码

//if (!IsAllowedExtension(FileUpload1))
                //{
                //    this.lb_info.Text = "上传文件格式不正确！";
                //}
                if (IsAllowedExtension(FileUpload1) == true)
改为：

if (!IsAllowedExtension(FileUpload1))
                {
                    this.lb_info.Text = "上传文件格式不正确！";
                }
else if (IsAllowedExtension(FileUpload1) == true)
即变成服务器端检查上传文件类型。

5 服务器端检查上传文件的类型（文件内部真正的格式）

<body>
    <form id="form1" runat="server">
    <div>
        <table>
            <tr>
                <td colspan="2">
                    服务器检查上传文件类型</td>
            </tr>
            <tr>
                <td style=" 444px">
                    <asp:FileUpload ID="FileUpload1" runat="server" Width="432px" /></td>
                <td style=" 80px">
                    <asp:Button ID="bt_upload" runat="server" Text="上传图片" OnClick="bt_upload_Click" /></td>
            </tr>
            <tr>
                <td colspan="2" style="height: 21px">
                    <asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="515px"></asp:Label></td>
            </tr>
        </table>
    </div>
    </form>
</body>
后台代码：

using System;
using System.Data;
using System.Configuration;
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;
using System.IO;

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();
        }
    }
    private static bool IsAllowedExtension(FileUpload upfile)
    {
        FileStream fs = new FileStream(upfile.PostedFile.FileName, FileMode.Open, FileAccess.Read);
        BinaryReader r = new 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"||fileclass=="6677"||fileclass=="13780")//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;
        }
    }
}

查看全文

相关阅读:
awk 入门教程【转】
xargs 命令教程【转】
redis 执行lua脚本
 SpringMVC 执行过程分析
 EurekaClient 服务注册、发现、续约
 Springboot 自动配置 & 自定义Starter
Netty 实现HttpServer
Spring中@Import 用法
 Netty自定义任务&Future-Listener机制
 Springboot + Netty + WebSocket 实现简单的聊天

原文地址：https://www.cnblogs.com/skyshenwei/p/1629684.html