Generate QRCode

http://www.aspdotnet-suresh.com/2017/04/aspnet-generate-and-read-qr-code-in-web-application-using-csharp-vbnet.html

install  zxing.net c# library

PM> Install-Package ZXing.Net -Version 0.15.0

<form id="form1" runat="server">
<div>
<asp:TextBox ID="txtCode" runat="server"></asp:TextBox>
<asp:Button ID="btnGenerate" runat="server" Text="Generate QR Code" OnClick="btnGenerate_Click" />
<hr />
<asp:Image ID="imgQRCode" Width="100px" Height="100px" runat="server" Visible="false" />     <br /><br />
<asp:Button ID="btnRead" Text="Read QR Image" runat="server" OnClick="btnRead_Click" />  <br /><br />
<asp:Label ID="lblQRCode" runat="server"></asp:Label>
</div>
</form>


using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;

using ZXing;

namespace TestProject
{
    public partial class QrCode : System.Web.UI.Page
    {

        protected void Page_Load(object sender, EventArgs e)
        {

        }
        protected void btnGenerate_Click(object sender, EventArgs e)
        {
            GenerateCode(txtCode.Text);
        }
        protected void btnRead_Click(object sender, EventArgs e)
        {
            ReadQRCode();
        }
        // Generate QRCode
        private void GenerateCode(string name)
        {
            var writer = new BarcodeWriter();
            writer.Format = BarcodeFormat.QR_CODE;
            var result = writer.Write(name);
            string path = Server.MapPath("~/image/QRCodeImage.jpg");
            var barcodeBitmap = new Bitmap(result);




            using (MemoryStream memory = new MemoryStream())
            {
                using (FileStream fs = new FileStream(path, FileMode.Create, FileAccess.ReadWrite))
                {
                    barcodeBitmap.Save(memory, ImageFormat.Jpeg);
                    byte[] bytes = memory.ToArray();
                    fs.Write(bytes, 0, bytes.Length);
                }
            }
            imgQRCode.Visible = true;
            imgQRCode.ImageUrl = "~/image/QRCodeImage.jpg";

        }
        // Read Code from QR Image
        private void ReadQRCode()
        {
            var reader = new BarcodeReader();
            string filename = Path.Combine(Request.MapPath("~/image"), "QRCodeImage.jpg");
            // Detect and decode the barcode inside the bitmap
            var result = reader.Decode(new Bitmap(filename));
            if (result != null)
            {
                lblQRCode.Text = "QR Code: " + result.Text;
            }
        }
    }

}