使用QRCoder库版本1.3.5时无法访问QRCode或QRCodeGenerator.QRCode类

Question

当我使用QRCode.dll版本1.3.5或检查了版本1.3.3但出现相同问题时，我无法访问QRCode类或QRCodeGenerator.QRCode。

 public void GenerateQRCode(string code)
    {
        var imgUrl="";
        //string code = txtCode.Text;
        QRCodeGenerator qrGenerator = new QRCodeGenerator();

        QRCodeData qrCodeData = qrGenerator.CreateQrCode(code, QRCodeGenerator.ECCLevel.Q);

        QRCode  qrCode = new QRCode(qrCodeData); 

        // I am getting error in above line, or I am using below line of code but getting error. Unable to access QRCode withQRCodeGenerator.

        QRCodeGenerator.QRCode qrCode = qrGenerator.CreateQrCode(code, QRCodeGenerator.ECCLevel.Q);

        using (Bitmap bitMap = qrCode.GetGraphic(20))
        {
            using (MemoryStream ms = new MemoryStream())
            {
                bitMap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
                byte[] byteImage = ms.ToArray(); 
                imgUrl= "data:image/png;base64," + Convert.ToBase64String(byteImage);
            } 
        }
    }

上面是我在Web API 2中使用的代码