Generate QR Code with Logo in Centre using C# in ASP.Net

Hi @Joey,

I got something. But it appears this code uses a different library. In my project, I already installed Zxing QR encoder library.

The library used is QRCoder and I downloaded from Nuget.

protected void Page_Load(object sender, EventArgs e)
{
    Showdata1();
 
}
public void Showdata1()
{
    //In this public void, the logo image is read from the database table and displayed on the web form.
    string connectionString = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
    using (SqlConnection con = new SqlConnection(connectionString))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT * FROM tblFiles WHERE Id = 1", con))
        {
 
            con.Open();
            SqlDataReader dr = cmd.ExecuteReader();
            if (dr.Read())
            {
                byte[] bytes = (byte[])dr["Data"];
                LogoImage.ImageUrl = "data:image/jpeg;base64," + Convert.ToBase64String(bytes);
            }
        }
    }
}
protected void btnGenerate_Click(object sender, EventArgs e)
{
    string code = txtCode.Text;
    byte[] image = Convert.FromBase64String(LogoImage.ImageUrl.Replace("data:image/jpeg;base64,", String.Empty));
    QRCodeGenerator qrGenerator = new QRCodeGenerator();
    QRCodeData qrCodeData = qrGenerator.CreateQrCode(code, QRCodeGenerator.ECCLevel.Q); QRCode qrCode = new QRCode(qrCodeData);
    using (Bitmap bitMap = qrCode.GetGraphic(40))
    {
        Bitmap overlay = new Bitmap(new MemoryStream(image));
        int deltaHeigth = bitMap.Height - overlay.Height;
        int deltaWidth = bitMap.Width - overlay.Width;
        Graphics g = Graphics.FromImage(bitMap);
        g.DrawImage(overlay, new System.Drawing.Point(deltaWidth / 2, deltaHeigth / 2));
        using (MemoryStream ms = new MemoryStream())
        {
            bitMap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
            byte[] byteImage = ms.ToArray();
            QRImage1.ImageUrl = "data:image/png;base64," + Convert.ToBase64String(byteImage);
        }
 
    }
}

I made some changes to the above code to suit what I want. 

HTML

<asp:TextBox ID="txtCode" runat="server"></asp:TextBox>
<asp:Image ID="LogoImage" runat="server" />
<asp:Image ID="QRImage1" runat="server" Width="150" Height="150" />

C#

protected void Page_Load(object sender, EventArgs e)
{
    Showdata1();
    if (!this.IsPostBack)
    {
   //This is where I call the below GenrateQRCode method, to show in Image2 control and a url is attached to it with QueryString
        byte[] QRBytes = GenerateQRCode(ToAbsoluteUrl("~/detailspage.aspx") + "?Id=" + Request.QueryString["id"]);
        Image2.ImageUrl = "data:image/jpg;base64," + Convert.ToBase64String(QRBytes);
    }
}
 
public void Showdata1()
{
        //In this public void, the logo image is read from the database table and displayed on the web form.
        string connectionString = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
        using (SqlConnection con = new SqlConnection(connectionString))
        {
            using (SqlCommand cmd = new SqlCommand("SELECT * FROM tblFiles WHERE Id = 1", con))
            {
 
                con.Open();
                SqlDataReader dr = cmd.ExecuteReader();
                if (dr.Read())
                {
                    byte[] bytes = (byte[])dr["Data"];
                    LogoImage.ImageUrl = "data:image/jpeg;base64," + Convert.ToBase64String(bytes);
                }
            }
        }
}
 
public string ToAbsoluteUrl(string relativeUrl)
{
    if (string.IsNullOrEmpty(relativeUrl))
    {
        return relativeUrl;
    }
    if (relativeUrl.StartsWith("/"))
    {
        relativeUrl = relativeUrl.Insert(0, "~");
    }
    if (!relativeUrl.StartsWith("~/"))
    {
        relativeUrl = relativeUrl.Insert(0, "~/");
    }
    var url = HttpContext.Current.Request.Url;
    var port = url.Port != 80 ? (":" + url.Port) : String.Empty;
 
    return String.Format("{0}://{1}{2}{3}", url.Scheme, url.Host, port, VirtualPathUtility.ToAbsolute(relativeUrl));
}
 
public byte[] GenerateQRCode(string url)
{
        // string code = txtCode.Text;
        byte[] image = Convert.FromBase64String(LogoImage.ImageUrl.Replace("data:image/jpeg;base64,", String.Empty));
        QRCodeGenerator qrGenerator = new QRCodeGenerator();
        QRCodeData qrCodeData = qrGenerator.CreateQrCode(url, QRCodeGenerator.ECCLevel.Q); QRCode qrCode = new QRCode(qrCodeData);
        using (Bitmap bitMap = qrCode.GetGraphic(40))
        {
            Bitmap overlay = new Bitmap(new MemoryStream(image));
            int deltaHeigth = bitMap.Height - overlay.Height;
            int deltaWidth = bitMap.Width - overlay.Width;
            Graphics g = Graphics.FromImage(bitMap);
            g.DrawImage(overlay, new System.Drawing.Point(deltaWidth / 2, deltaHeigth / 2));
            using (MemoryStream ms = new MemoryStream())
            {
                bitMap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
                return ms.ToArray();
            } 
        }
}