swfupload实现图片及缩略图上传

参考部分网上搜到的方法，自己加以修改。

1、修改Thumbnail.cs

using System;

public class Thumbnail
{
    private string id;
    private byte[] originalData;
    private byte[] data;

public Thumbnail(string id, byte[] originalData, byte[] data)
    {
        this.ID = id;
        this.OriginalData = originalData;
        this.Data = data;
    }

public string ID
    {
        get
        {
            return this.id;
        }
        set
        {
            this.id = value;
        }
    }

public byte[] OriginalData
    {
        get
        {
            return this.originalData;
        }
        set
        {
            this.originalData = value;
        }
    }

public byte[] Data
    {
        get
        {
            return this.data;
        }
        set
        {
            this.data = value;
        }
    }
}
2、修改upload.aspx.cs

using System;
using System.Web;
using System.IO;
using System.Collections.Generic;

public partial class upload : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

System.Drawing.Image thumbnail_image = null;
        System.Drawing.Image original_image = null;
        System.Drawing.Bitmap final_image = null;
        System.Drawing.Graphics graphic = null;
        MemoryStream ms = null;
        MemoryStream maxms = null;

try
        {
            //获得数据
            HttpPostedFile jpeg_image_upload = Request.Files["Filedata"];

//获得上传的图片
            original_image = System.Drawing.Image.FromStream(jpeg_image_upload.InputStream);

int width = original_image.Width;//原始图片宽度
            int height = original_image.Height;//原始图片高度
            int target_width = 100;//目标图片宽度
            int target_height = 100;//目标图片高度
            int new_width, new_height;//新宽度和新高度

float target_ratio = (float)target_width / (float)target_height;//目标图片宽高比
            float image_ratio = (float)width / (float)height;//原始图片宽高比

//计算新的长度和宽度
            if (target_ratio > image_ratio)
            {
                new_height = target_height;
                new_width = (int)Math.Floor(image_ratio * (float)target_height);
            }
            else
            {
                new_height = (int)Math.Floor((float)target_width / image_ratio);
                new_width = target_width;
            }

new_width = new_width > target_width ? target_width : new_width;
            new_height = new_height > target_height ? target_height : new_height;

            //创建缩略图

//thumbnail_image = original_image.GetThumbnailImage(new_width, new_height, null, System.IntPtr.Zero);

final_image = new System.Drawing.Bitmap(target_width, target_height);//目标图片的像素图
            graphic = System.Drawing.Graphics.FromImage(final_image);//目标图片的画板
            graphic.FillRectangle(new System.Drawing.SolidBrush(System.Drawing.Color.Black), new System.Drawing.Rectangle(0, 0, target_width, target_height));//用黑色填充目标图片大小的矩形框
            int paste_x = (target_width - new_width) / 2;//从原点位移x坐标
            int paste_y = (target_height - new_height) / 2;//从原点位移y坐标
            graphic.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;//插补模式
            //graphic.DrawImage(thumbnail_image, paste_x, paste_y, new_width, new_height);
            graphic.DrawImage(original_image, paste_x, paste_y, new_width, new_height);//画图

ms = new MemoryStream();//创建一个新的内存流
            final_image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);//目标图片保存

maxms = new MemoryStream();//创建一个新的内存流
            original_image.Save(maxms, System.Drawing.Imaging.ImageFormat.Jpeg);//原始图片保存

string thumbnail_id = DateTime.Now.ToString("yyyyMMddHHmmssfff");//根据时间生成图片名
            Thumbnail thumb = new Thumbnail(thumbnail_id, maxms.ToArray(), ms.ToArray());

List<Thumbnail> thumbnails = Session["file_info"] as List<Thumbnail>;
            if (thumbnails == null)
            {
                thumbnails = new List<Thumbnail>();
                Session["file_info"] = thumbnails;
            }
            thumbnails.Add(thumb);

Response.StatusCode = 200;
            Response.Write(thumbnail_id);
        }
        catch
        {
            Response.StatusCode = 500;
            Response.Write("An error occured");
            Response.End();
        }
        finally
        {
            if (final_image != null) final_image.Dispose();
            if (graphic != null) graphic.Dispose();
            if (original_image != null) original_image.Dispose();
            if (thumbnail_image != null) thumbnail_image.Dispose();
            if (ms != null) ms.Close();
            if (maxms != null) maxms.Close();
            Response.End();
        }

}
}
3、上传事件

protected void btnSave_Click(object sender, EventArgs e)
    {
        if (Session["file_info"] != null)
        {
            List<Thumbnail> thumbnails = Session["file_info"] as List<Thumbnail>;

string UploadPath1 = Server.MapPath("HouseUploads/");
            string UploadPath2 = Server.MapPath("HouseUploads/Small/");
            string name1;
            string name2;

StringBuilder buffer = new StringBuilder();

foreach (Thumbnail img in thumbnails)
            {
                name1 = img.ID + ".jpg";
                name2 = "s_" + img.ID + ".jpg";

FileStream fs1 = new FileStream(UploadPath1 + img.ID + ".jpg", FileMode.Create);
                BinaryWriter bw1 = new BinaryWriter(fs1);
                bw1.Write(img.OriginalData);
                bw1.Close();
                fs1.Close();

FileStream fs2 = new FileStream(UploadPath2 + "s_" + img.ID + ".jpg", FileMode.Create);
                BinaryWriter bw2 = new BinaryWriter(fs2);
                bw2.Write(img.Data);
                bw2.Close();
                fs2.Close();

buffer.Append(name1 + "|");
            }

Session.Clear();

//以下为向数据库添加图片名称的代码，可自行修改。

if (HouseBLL.UpdatePhoto(housePhoto, buffer.ToString(), true, houseId))
            {
                labMessage.Text = "图片上传成功！";
                housePhoto = HouseBLL.GetHousePhoto(houseId);
                BindHousePhoto();
            }
            else
            {
                labMessage.Text = "图片上传失败！";
                housePhoto = HouseBLL.GetHousePhoto(houseId);
                BindHousePhoto();
            }
        }
    }

经测试，目前还未发现什么问题。

swfupload实现图片和缩略图上传。并将图片名保存到数据库