生成二维码

/// <summary>
/// 
/// </summary>
/// <param name="userCode"></param>
/// <returns></returns>
public string generateQRCode(string visitUrl)
        {
           
            string filename = string.Empty;
            string filepath = string.Empty;

            string txt_qr = userCode;
            string qrEncoding = "Byte";
            string Level = "M";
            string txt_ver = "7";
            string txt_size = "4";

            QRCodeEncoder qrCodeEncoder = new QRCodeEncoder();
            String encoding = qrEncoding;
            if (encoding == "Byte")
            {
                qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
            }
            else if (encoding == "AlphaNumeric")
            {
                qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.ALPHA_NUMERIC;
            }
            else if (encoding == "Numeric")
            {
                qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.NUMERIC;
            }
            try
            {
                int scale = Convert.ToInt16(txt_size);
                qrCodeEncoder.QRCodeScale = scale;
            }
            catch (Exception ex)
            {
                return "";
            }
            try
            {
                int version = Convert.ToInt16(txt_ver);
                qrCodeEncoder.QRCodeVersion = version;
            }
            catch (Exception ex)
            {
                return "";
            }
            string errorCorrect = Level;
            if (errorCorrect == "L")
                qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.L;
            else if (errorCorrect == "M")
                qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M;
            else if (errorCorrect == "Q")
                qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.Q;
            else if (errorCorrect == "H")
                qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.H;

            Image image;
            String data = txt_qr;
            image = qrCodeEncoder.Encode(data);
            filename = Guid.NewGuid().ToString() + ".jpg";
            filepath = ConfigurationManager.AppSettings["userCode"] + filename;
            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 filepath;
        }

 注：在使用之前需要引用  “ThoughtWorks.QRCode.dll”  

 下载地址：ThoughtWorks.QRCode.zip