Cómo Leer un Código de Barras desde la Cámara en VB .NET

How to Read a Barcode from Camera in VB .NET

1. Create a new VB.NET Project in Visual Studio
2. Install the IronBarcode Library and apply it to your project
3. Get the barcode from the camera as an image using the AForge Library
4. Decode the barcode image using IronBarcode

Prerequisites

1. Visual Studio: Ensure you have Visual Studio or any other VB.NET development environment installed.
2. Compatible Camera: Ensure said camera is connected to your device.
3. NuGet Package Manager: Make sure you can use NuGet to manage packages in your project.

Step 1: Create a New Visual Basic .NET Project in Visual Studio

Create a new VB.NET Windows Forms application (or use an existing project) where you want to host the code to read the barcode from your camera.

In the next step, you can provide the solution and project names.

Select the .NET version and click the "Create" button.

Step 2: Install the IronBarcode Library

Open your VB.NET project and install the IronBarcode library using the NuGet Package Manager Console:

Install-Package BarCode

The NuGet package can also be installed using Visual Studio's NuGet Package Manager, as shown below.

Step 3: Reading the Barcode from the Camera

To scan the feed and capture the image from the camera, we need the AForge Library. Install it as below from the NuGet package manager.

The next step is to add the PictureBox control from the ToolBox to the forms. This is used to capture the image from the camera.

Then copy the below code to the forms application and create the VB .NET barcode reader component from IronBarcode.

Imports IronBarCode
Imports AForge.Video
Imports AForge.Video.DirectShow

Public Class Form1
    Private videoDevices As FilterInfoCollection
    Private videoSource As VideoCaptureDevice

    ' Event handler for form load
    Private Sub MainForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        videoDevices = New FilterInfoCollection(FilterCategory.VideoInputDevice)
        If videoDevices.Count > 0 Then
            videoSource = New VideoCaptureDevice(videoDevices(0).MonikerString)
            AddHandler videoSource.NewFrame, AddressOf VideoSource_NewFrame
            videoSource.Start()
        Else
            MessageBox.Show("No video devices found.")
            Close()
        End If
    End Sub

    ' Event handler for capturing and processing new frame from the video source
    Private Sub VideoSource_NewFrame(sender As Object, eventArgs As NewFrameEventArgs)
        pictureBoxCamera.Image = DirectCast(eventArgs.Frame.Clone(), Bitmap)

        ' Process each frame for barcode recognition
        Dim image = DirectCast(pictureBoxCamera.Image, Bitmap)
        Dim result = BarcodeReader.QuicklyReadOneBarcode(image, BarcodeEncoding.QRCode Or BarcodeEncoding.Code128)

        If result IsNot Nothing Then
            ' Barcode found, handle the new result (e.g., display the barcode value)
            Dim barcodeValue As String = result.Text
            ShowBarcodeResult(barcodeValue)
        End If
    End Sub

    ' Method to display the barcode result
    Private Sub ShowBarcodeResult(barcodeValue As String)
        ' Invoke on UI thread to update UI controls
        If InvokeRequired Then
            Invoke(New Action(Of String)(AddressOf ShowBarcodeResult), barcodeValue)
        Else
            ' Display the barcode value in a MessageBox or any other UI element
            MessageBox.Show("Barcode Value: " & barcodeValue, "Barcode Detected")
        End If
    End Sub

    ' Event handler for form closing
    Private Sub MainForm_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
        If videoSource IsNot Nothing AndAlso videoSource.IsRunning Then
            videoSource.SignalToStop()
            videoSource.WaitForStop()
        End If
    End Sub
End Class

Imports IronBarCode
Imports AForge.Video
Imports AForge.Video.DirectShow

Public Class Form1
    Private videoDevices As FilterInfoCollection
    Private videoSource As VideoCaptureDevice

    ' Event handler for form load
    Private Sub MainForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        videoDevices = New FilterInfoCollection(FilterCategory.VideoInputDevice)
        If videoDevices.Count > 0 Then
            videoSource = New VideoCaptureDevice(videoDevices(0).MonikerString)
            AddHandler videoSource.NewFrame, AddressOf VideoSource_NewFrame
            videoSource.Start()
        Else
            MessageBox.Show("No video devices found.")
            Close()
        End If
    End Sub

    ' Event handler for capturing and processing new frame from the video source
    Private Sub VideoSource_NewFrame(sender As Object, eventArgs As NewFrameEventArgs)
        pictureBoxCamera.Image = DirectCast(eventArgs.Frame.Clone(), Bitmap)

        ' Process each frame for barcode recognition
        Dim image = DirectCast(pictureBoxCamera.Image, Bitmap)
        Dim result = BarcodeReader.QuicklyReadOneBarcode(image, BarcodeEncoding.QRCode Or BarcodeEncoding.Code128)

        If result IsNot Nothing Then
            ' Barcode found, handle the new result (e.g., display the barcode value)
            Dim barcodeValue As String = result.Text
            ShowBarcodeResult(barcodeValue)
        End If
    End Sub

    ' Method to display the barcode result
    Private Sub ShowBarcodeResult(barcodeValue As String)
        ' Invoke on UI thread to update UI controls
        If InvokeRequired Then
            Invoke(New Action(Of String)(AddressOf ShowBarcodeResult), barcodeValue)
        Else
            ' Display the barcode value in a MessageBox or any other UI element
            MessageBox.Show("Barcode Value: " & barcodeValue, "Barcode Detected")
        End If
    End Sub

    ' Event handler for form closing
    Private Sub MainForm_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
        If videoSource IsNot Nothing AndAlso videoSource.IsRunning Then
            videoSource.SignalToStop()
            videoSource.WaitForStop()
        End If
    End Sub
End Class

In this sample code, we have configured it to read QR codes and Code 128 barcodes. First, we use a PictureBox to capture barcode images from a webcam or any camera device by scanning the barcode. Then we create a bitmap image, which is then provided as input to the IronBarcode BarcodeReader class. This application reads the 2D barcode from images and decodes them. If a positive result is obtained after decoding, then the result is displayed in the message box.

{
    "IronBarcode.LicenseKey": "MYLICENSE.KEY.TRIAL"
}

Conclusion

Implementing barcode reading from a camera in VB.NET is a powerful feature that can enhance various applications across different industries. By leveraging libraries like IronBarcode and integrating them into your VB.NET project, you can create efficient and reliable barcode scanning applications that meet the demands of today's technology-driven world. This guide serves as a starting point, and developers can further customize and optimize the solution based on their specific requirements, barcode types, and use cases.