C#.net 2张图片合并输出

/// <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="sourceImg">粘贴的源图片</param>
/// <param name="destImg">粘贴的目标图片</param>
public static System.Drawing.Image CombinImage(string sourceImg, string destImg)
{
System.Drawing.Image imgBack = System.Drawing.Image.FromFile(sourceImg);     //相框图片
System.Drawing.Image img = System.Drawing.Image.FromFile(destImg);        //照片图片

//从指定的System.Drawing.Image创建新的System.Drawing.Graphics
Graphics g = Graphics.FromImage(imgBack);

g.DrawImage(imgBack, 0, 0, 148, 124);      // g.DrawImage(imgBack, 0, 0, 相框宽, 相框高);
//g.FillRectangle(System.Drawing.Brushes.Black, 16, 16, (int)112 + 2, ((int)73 + 2));//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, 17, 17, 112, 73);
GC.Collect();

//输出文件流
System.IO.MemoryStream ms = new System.IO.MemoryStream();
imgBack.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
System.Web.HttpContext.Current.Response.ClearContent();
System.Web.HttpContext.Current.Response.ContentType = "image/png";
System.Web.HttpContext.Current.Response.BinaryWrite(ms.ToArray());
imgBack.Dispose();
return imgBack;
}