asp.net(C#)使用QRCode生成图片中心加Logo或图像的二

<%@ WebHandler Language="C#" Class="GetQRCode" %>
using System;
using System.Web;
using ThoughtWorks.QRCode.Codec;
using ThoughtWorks.QRCode.Codec.Data;
using ThoughtWorks.QRCode.Codec.Util;
using System.IO;
using System.Text;
using System.Drawing;
using System.Drawing.Drawing2D;
public class GetQRCode : IHttpHandler
{
  public void ProcessRequest(HttpContext context)
  {
    String data = context.Request["CodeText"];
    if (!string.IsNullOrEmpty(data))
    {
      QRCodeEncoder qrCodeEncoder = new QRCodeEncoder();
      qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
      qrCodeEncoder.QRCodeScale = 4;
      qrCodeEncoder.QRCodeVersion = 8;
      qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M;
      System.Drawing.Image image = qrCodeEncoder.Encode(data);
      System.IO.MemoryStream MStream = new System.IO.MemoryStream();
      image.Save(MStream, System.Drawing.Imaging.ImageFormat.Png);
      System.IO.MemoryStream MStream1 = new System.IO.MemoryStream();
      CombinImage(image, context.Server.MapPath("~/images/201292891051540.jpg")).Save(MStream1, System.Drawing.Imaging.ImageFormat.Png);
      context.Response.ClearContent();
      context.Response.ContentType = "image/png";
      context.Response.BinaryWrite(MStream1.ToArray());
      //image.Dispose();
      MStream.Dispose();
      MStream1.Dispose();
    }
    context.Response.Flush();
    context.Response.End();
  }
  /// <summary>
  /// 调用此函数后使此两种图片合并，类似相册，有个
  /// 背景图，中间贴自己的目标图片
  /// </summary>
  /// <param name="imgBack">粘贴的源图片</param>
  /// <param name="destImg">粘贴的目标图片</param>
  public static Image CombinImage(Image imgBack, string destImg)
  {
    Image img = Image.FromFile(destImg);    //照片图片
    if (img.Height != 65 || img.Width != 65)
    {
      img = KiResizeImage(img, 65, 65, 0);
    }
    Graphics g = Graphics.FromImage(imgBack);
    g.DrawImage(imgBack, 0, 0, imgBack.Width, imgBack.Height);   //g.DrawImage(imgBack, 0, 0, 相框宽, 相框高);
    //g.FillRectangle(System.Drawing.Brushes.White, imgBack.Width / 2 - img.Width / 2 - 1, imgBack.Width / 2 - img.Width / 2 - 1,1,1);//相片四周刷一层黑色边框
    //g.DrawImage(img, 照片与相框的左边距, 照片与相框的上边距, 照片宽, 照片高);
    g.DrawImage(img, imgBack.Width / 2 - img.Width / 2, imgBack.Width / 2 - img.Width / 2, img.Width, img.Height);
    GC.Collect();
    return imgBack;
  }
  /// <summary>
  /// Resize图片
  /// </summary>
  /// <param name="bmp">原始Bitmap</param>
  /// <param name="newW">新的宽度</param>
  /// <param name="newH">新的高度</param>
  /// <param name="Mode">保留着，暂时未用</param>
  /// <returns>处理以后的图片</returns>
  public static Image KiResizeImage(Image bmp, int newW, int newH, int Mode)
  {
    try
    {
      Image b = new Bitmap(newW, newH);
      Graphics g = Graphics.FromImage(b);
      // 插值算法的质量
      g.InterpolationMode = InterpolationMode.HighQualityBicubic;
      g.DrawImage(bmp, new Rectangle(0, 0, newW, newH), new Rectangle(0, 0, bmp.Width, bmp.Height), GraphicsUnit.Pixel);
      g.Dispose();
      return b;
    }
    catch
    {
      return null;
    }
  }
  public bool IsReusable
  {
    get
    {
      return false;
    }
  }
}