.NET生成带Logo的二维码

 HttpContext context = HttpContext.Current;
            String data = "二维码的内容";//如果是链接会跳转
            if (!string.IsNullOrEmpty(data))
            {
                QRCodeEncoder encoder = new QRCodeEncoder();
                Bitmap imgBack = encoder.Encode(data, System.Text.Encoding.UTF8);
                Image logoImg = Image.FromFile(context.Server.MapPath("~/images/1.png"));
                System.Drawing.Image bitmap = new System.Drawing.Bitmap(280, 280);
                System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);
                g.DrawImage(imgBack, 0, 0, 280, 280);
                g.DrawImage(logoImg, 140 - 40, 140 - 40, 80, 80);
                bitmap.Save(context.Server.MapPath("~/images/2.png"));
            }