后台：
/// 生成二维码
/// </summary>
/// <param name="strData">要生成的文字或者数字，支持中文。如： "4408810820 深圳－广州" 或者：4444444444</param>
/// <param name="qrEncoding">三种尺寸：BYTE ，ALPHA_NUMERIC，NUMERIC</param>
/// <param name="level">大小：L M Q H</param>
/// <param name="version">版本：如 8</param>
/// <param name="scale">比例：如 4</param>
/// <returns></returns>
public ActionResult CreateCode_Choose(string strData， string qrEncoding， string level， int version， int scale)
{
QRCodeEncoder qrCodeEncoder = new QRCodeEncoder();
string encoding = qrEncoding;
switch (encoding)
{
case "Byte":
qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
break;
case "AlphaNumeric":
qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.ALPHA_NUMERIC;
break;
case "Numeric":
qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.NUMERIC;
break;
default:
qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
break;
}
qrCodeEncoder.QRCodeScale = scale;
qrCodeEncoder.QRCodeVersion = version;
switch (level)
{
case "L":
qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.L;
break;
case "M":
qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M;
break;
case "Q":
qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.Q;
break;
default:
qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.H;
break;
}
//文字生成图片
Image image = qrCodeEncoder.Encode(strData);
string filename = DateTime.Now.ToString("yyyymmddhhmmssfff").ToString() + ".jpg";
string filepath = Server.MapPath(@"~Upload") + "\" + filename;
//如果文件夹不存在，则创建
//if (!Directory.Exists(filepath))
//    Directory.CreateDirectory(filepath);
System.IO.FileStream fs = new System.IO.FileStream(filepath， System.IO.FileMode.OpenOrCreate， System.IO.FileAccess.Write);
image.Save(fs， System.Drawing.Imaging.ImageFormat.Jpeg);
fs.Close();
image.Dispose();
return Content(@"/Upload/" + filename);
}