图片合成

 protected System.Drawing.Image ReturnImage(string strPhotoPath)
        {
            FileStream fstream = new FileStream(strPhotoPath, FileMode.OpenOrCreate, FileAccess.Read);
            byte[] byData = new byte[fstream.Length];
            fstream.Read(byData, 0, System.Convert.ToInt32(fstream.Length));
            fstream.Close();
            System.IO.MemoryStream stream = new System.IO.MemoryStream(byData, true);
            stream.Write(byData, 0, byData.Length);
            Bitmap bmp = new Bitmap(stream);
            System.Drawing.Image image = bmp;
            return bmp;
        }

string str0 = System.IO.Path.GetDirectoryName(Page.Request.PhysicalPath) + "/images/2.jpg ";//像框文件的路径 
            string str1 = System.IO.Path.GetDirectoryName(Page.Request.PhysicalPath) + "/images/1.png ";//照片文件的全路径 
            System.Drawing.Image img0 = ReturnImage(str0);
            System.Drawing.Image img1 = ReturnImage(str1);
            //1024 合成图片的宽 768 合成图片的高
            System.Drawing.Image newImage = img0.GetThumbnailImage(1024, 768, null, new IntPtr());
            Graphics g = Graphics.FromImage(img0);
            g.DrawImage(img0, 0, 0, 1024, 768);
            //10小图距离大图的左边距 11小图距离大图的上边距
            g.DrawImage(img1, 10, 11, img1.Width, img1.Height);
            //保存图片
            img0.Save(System.IO.Path.GetDirectoryName(Page.Request.PhysicalPath) + "/images/2.jpg");