Read multiple QR Codes in ASP.Net using C# and VB.Net

Hi counterkin,

Refer below sample code to read multiple QRCode and display the result.

I am making use of ZXing.Net library will be used to read QR code image.

Download ZXing.Net package

You will need to install the ZXing.Net package using the following command.

Install-Package ZXing.Net -Version 0.16.9

HTML

<asp:FileUpload ID="FileUpload1" runat="server" />
<asp:Button ID="btnRead" runat="server" Text="Read" OnClick="OnRead" /><br />
<br />
<asp:Label runat="server" ID="lblQRCodeText"></asp:Label>

Namespaces

You will need to import the following namespaces.

C#

using System.Drawing;
using ZXing;
using ZXing.Common;
using ZXing.Multi.QrCode;

VB.Net

Imports System.Drawing
Imports ZXing
Imports ZXing.Common
Imports ZXing.Multi.QrCode

Code

C#

protected void OnRead(object sender, EventArgs e)
{
    // Create Bitmap from selected file.
    using (Bitmap bitMap = (Bitmap)Bitmap.FromStream(FileUpload1.PostedFile.InputStream))
    {
        // Read the QRCode.
        BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(new BitmapLuminanceSource(bitMap)));
        // QRCodeMultiReader object accept BinaryBitmap and decode it.
        List<string> results = new QRCodeMultiReader().decodeMultiple(binaryBitmap).Select(x => x.Text).ToList();
        foreach (string text in results)
        {
            lblQRCodeText.Text += text + "<br />";
        }
    }
}

VB.Net

Protected Sub OnRead(ByVal sender As Object, ByVal e As EventArgs)
    ' Create Bitmap from selected file.
    Using bitMap As Bitmap = CType(Bitmap.FromStream(FileUpload1.PostedFile.InputStream), Bitmap)
        ' Read the QRCode.
        Dim binaryBitmap As BinaryBitmap = New BinaryBitmap(New HybridBinarizer(New BitmapLuminanceSource(bitMap)))
        ' QRCodeMultiReader object accept BinaryBitmap and decode it.
        Dim results As List(Of String) = New QRCodeMultiReader().decodeMultiple(binaryBitmap).Select(Function(x) x.Text).ToList()
        For Each text As String In results
            lblQRCodeText.Text += text & "<br />"
        Next
    End Using
End Sub

Screenshots

Sample QR Code Image

After Reading the QR Code