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(, );

                System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);

                g.DrawImage(imgBack, , , , );

                g.DrawImage(logoImg,  - ,  - , , );

                bitmap.Save(context.Server.MapPath("~/images/2.png"));

            }