ASP.NET 自由裁剪图片

   protected void btnUpload_Click(object sender, EventArgs e)  //上传图片
        {
            try
            {
                string proimg = Xiaobin.Utility.Tool.Upload(fuimg, new string[] { ".jpg", ".png", ".gif", ".bmp" }, 1, Server.MapPath("/upload/"));
                img.ImageUrl = "/upload/" + proimg;
                img.ToolTip = proimg;
            }
            catch (Exception ex)
            {
                Xiaobin.Utility.Tool.ExecJs(ex.Message, this.Page);
            }        
        }

        public string GetImg()  //获取图片名称
        {
            string str = "";
            string teImg = img.ImageUrl;
            str = "var ic = new ImgCropper('bgDiv', 'dragDiv', '" + teImg + "', {Width: 300, Height: 400, Color: '#000',Resize: true,Right: 'rRight', Left: 'rLeft', Up: 'rUp', Down: 'rDown',RightDown: 'rRightDown', LeftDown: 'rLeftDown', RightUp: 'rRightUp', LeftUp: 'rLeftUp',Preview: 'viewDiv', viewWidth: 300, viewHeight: 300})";
            return str;
        }  

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

namespace XiaobinManage.Web
{
    /// <summary>
    /// ImgCropper 的摘要说明
    /// </summary>
    public class ImgCropper : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            string Pic = Convert.ToString(context.Request["p"]);
            int PointX = Convert.ToInt32(context.Request["x"]);
            int PointY = Convert.ToInt32(context.Request["y"]);
            int CutWidth = Convert.ToInt32(context.Request["w"]);
            int CutHeight = Convert.ToInt32(context.Request["h"]);
            int PicWidth = Convert.ToInt32(context.Request["pw"]);
            int PicHeight = Convert.ToInt32(context.Request["ph"]);

            context.Response.ContentType = "image/jpeg";
            ResetImg(System.Web.HttpContext.Current.Server.MapPath(Pic), PicWidth, PicHeight, PointX, PointY, CutWidth, CutHeight).WriteTo(context.Response.OutputStream);

            //ImgCropper.ashx?p=/upload/20150122/9f0e5c90-e748-4e13-8af5-d9fe2c7c154c.jpg&x=2&y=6&w=267&h=197&pw=300&ph=214&0.6161095989903618  //前台是显示成这种缓存图片

            string[] ss = Pic.Split('/');  //分割
            string small_img = System.Web.HttpContext.Current.Server.MapPath("/upload/" + ss[2] + "/small_" + ss[3]);

            Image imgPhoto = Image.FromFile(System.Web.HttpContext.Current.Server.MapPath(Pic));

             // 把缓存图片生成出来
            CutImage(System.Web.HttpContext.Current.Server.MapPath(Pic), small_img, PointX * imgPhoto.Width / PicWidth, PointY * imgPhoto.Height / PicHeight, CutWidth * imgPhoto.Width / PicWidth, CutHeight * imgPhoto.Height / PicHeight);  
        }

        public MemoryStream ResetImg(string ImgFile, int PicWidth, int PicHeight, int PointX, int PointY, int CutWidth, int CutHeight)
        {
            Image imgPhoto = Image.FromFile(ImgFile);
            Bitmap bmPhoto = new Bitmap(CutWidth, CutHeight, System.Drawing.Imaging.PixelFormat.Format24bppRgb);

            Graphics gbmPhoto = Graphics.FromImage(bmPhoto);
            gbmPhoto.DrawImage(imgPhoto, new Rectangle(0, 0, CutWidth, CutHeight), PointX * imgPhoto.Width / PicWidth, PointY * imgPhoto.Height / PicHeight, CutWidth * imgPhoto.Width / PicWidth, CutHeight * imgPhoto.Height / PicHeight, GraphicsUnit.Pixel);

            MemoryStream ms2 = new MemoryStream();
            bmPhoto.Save(ms2, System.Drawing.Imaging.ImageFormat.Jpeg);

            imgPhoto.Dispose();
            gbmPhoto.Dispose();
            bmPhoto.Dispose();

            return ms2;
        }

        /// <summary>    
        /// 裁剪图片    
        /// </summary>    
        /// <param name="sourceImg">原图片路径</param>    
        /// <param name="desImg">裁剪图片路径</param>    
        /// <param name="left">X</param>    
        /// <param name="top">Y</param>    
        /// <param name="width">宽</param>    
        /// <param name="height">高</param>    
        public static void CutImage(string sourceImg, string desImg, int left, int top, int width, int height)
        {
            System.Drawing.Image img = System.Drawing.Bitmap.FromFile(sourceImg);
            System.Drawing.Image imgToSave = new System.Drawing.Bitmap(width, height);
            System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(imgToSave);
            RectangleF sourceRect = new RectangleF(left, top, width, height);
            RectangleF destinationRect = new RectangleF(0, 0, width, height);
            g.DrawImage(img, destinationRect, sourceRect, GraphicsUnit.Pixel);
            g.Save();
            imgToSave.Save(desImg, System.Drawing.Imaging.ImageFormat.Jpeg);
            g.Dispose();
            imgToSave.Dispose();
            img.Dispose();
        }
        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}