Creating a Barcode Scanner in VB.NET Tutorial

Install IronBarcode NuGet Package

You can install the IronBarcode NuGet Package using the Package Manager Console. Enter the following command:

Install-Package BarCode

The above command will download and install the IronBarcode Library with all necessary dependencies.

Alternatively, you can also download it from the Manage NuGet package for the solution by browsing it.

Let's proceed further to generate a barcode image using VB.NET.

Generate Barcode Image

Creating barcodes is straightforward. You can use the BarcodeWriter class to generate various types of barcodes. Once we have our barcode, we can save it as an image. The barcode image can be accessed as an Image or converted to a Bitmap. We’ll create a simple Code128 barcode with the value “0987654ABCD0987654”. Here’s how you can do it:

Sub Main(args As String())
    Dim myBarcode = BarcodeWriter.CreateBarcode("0987654ABCD0987654", BarcodeWriterEncoding.Code128)
    ' Save the barcode as an image
    myBarcode.SaveAsImage("myCode128Barcode.jpeg")
End Sub

Sub Main(args As String())
    Dim myBarcode = BarcodeWriter.CreateBarcode("0987654ABCD0987654", BarcodeWriterEncoding.Code128)
    ' Save the barcode as an image
    myBarcode.SaveAsImage("myCode128Barcode.jpeg")
End Sub

The above code snippet utilizes the IronBarcode library to generate a Code 128 barcode with the data "0987654ABCD0987654". The BarcodeWriter.CreateBarcode method is employed, specifying the Code128 encoding. Subsequently, the created barcode is saved as a JPEG image file named "myCode128Barcode.jpeg" using the SaveAsImage method. The ability to change the BarcodeWriterEncoding parameter allows for flexibility in selecting different barcode symbologies according to specific needs, with options such as EAN13, EAN8, Code Bar, MSI, ITF, PDF417, QR codes, or Data Matrix codes offered by the IronBarcode library.

If you wish to save the generated barcode in formats other than JPEG, the IronBarcode library provides various methods for different file formats. You can use methods like SaveAsHtmlFile, SaveAsPDF, SaveAsTiff, SaveAsPng, and others, depending on your requirements. For example, if you want to save the barcode as an HTML file, you can replace the SaveAsImage line with myBarcode.SaveAsHtmlFile("myCode128Barcode.html"). Similarly, for other formats, you can use the corresponding methods, providing the desired file name and extension. This flexibility enables the adaptation of the generated barcode to different file formats to suit specific application needs.

The generated barcode image is as:

Resizing and Saving

After creating a barcode, you can resize it easily. The following code will set its max width to 650 pixels and max height to 300 pixels.

Dim myBarcode = BarcodeWriter.CreateBarcode("0987654ABCD0987654", BarcodeWriterEncoding.Code128)
myBarcode.ResizeTo(650, 300)
' Save the resized barcode as an image
myBarcode.SaveAsImage("myCode128Barcode.jpeg")

Dim myBarcode = BarcodeWriter.CreateBarcode("0987654ABCD0987654", BarcodeWriterEncoding.Code128)
myBarcode.ResizeTo(650, 300)
' Save the resized barcode as an image
myBarcode.SaveAsImage("myCode128Barcode.jpeg")

The ResizeTo method is used to resize a barcode image. In the provided example, myBarcode.ResizeTo(650, 300) is applied to the myBarcode object, suggesting that the barcode image is being resized to a width of 650 pixels and a height of 300 pixels.

This method is beneficial when you need to adjust the dimensions of the generated barcode image to meet specific requirements or to ensure it fits appropriately within a given layout or display area. Resizing can be useful in scenarios where you need to control the visual presentation of the barcode in terms of its size without altering the encoded data.

The output is as:

Barcode Reader

IronBarcode makes reading barcodes simple. You can extract barcode values from different sources:

1. From a file.
2. From a bitmap object.
3. From image files.
4. From a PDF (using ReadPdf).
5. From a memory stream.

The following code will scan the barcode image and print its value in the console.

Sub Main(args As String())
    Dim resultFromImage = BarcodeReader.Read("myCode128Barcode.jpeg") ' Scan barcodes
    For i As Integer = 0 To resultFromImage.Count - 1
        Console.WriteLine("Barcode Value: {0}", resultFromImage(i))
    Next i
End Sub

Sub Main(args As String())
    Dim resultFromImage = BarcodeReader.Read("myCode128Barcode.jpeg") ' Scan barcodes
    For i As Integer = 0 To resultFromImage.Count - 1
        Console.WriteLine("Barcode Value: {0}", resultFromImage(i))
    Next i
End Sub

The above code utilizes the IronBarcode library to read barcode data from an image file, "myCode128Barcode.jpeg." The BarcodeReader.Read method extracts the barcode information, and a loop is used to iterate through the results. The barcode values are then printed to the console using Console.WriteLine.

Additionally, you can also scan barcode data from various sources such as Bitmaps, AnyBitmaps, image files, and streams. These options provide flexibility in handling barcode data from different input formats, ranging from conventional image files like BMP and JPG to more generic representations like AnyBitmaps and streams. With this, we can develop our very own .NET Barcode reader, which reads barcodes and returns the result.

The output is displayed as:

Output

Add Advanced Options to Barcode Scanners

We can add more advanced features to our barcode scanners, such as customizing barcode scanning using BarcodeReaderOptions. Set parameters such as:

1. Reading speed (Faster, Balanced, Detailed, ExtremeDetail).
2. Whether to expect more than 1 barcode.
3. Specific barcode types to scan.
4. Multithreading for parallel processing.
5. Crop area to focus on relevant parts of the image.

We will read the following PDF file having three different barcode images.

The following code will add advanced features to our VB.NET barcode reader.

Sub Main(args As String())
    Dim resultFromPdf = BarcodeReader.ReadPdf("Barcode.pdf") ' Scan barcodes from a PDF
    Dim myOptionsExample As New BarcodeReaderOptions() With {
        .Speed = ReadingSpeed.Balanced,
        .ExpectMultipleBarcodes = True,
        .ExpectBarcodeTypes = BarcodeEncoding.AllOneDimensional,
        .Multithreaded = True,
        .MaxParallelThreads = 2,
        .CropArea = New System.Drawing.Rectangle(),
        .UseCode39ExtendedMode = True
    }
    For i As Integer = 0 To resultFromPdf.Count - 1
        Console.WriteLine("Barcode Value - {0} = {1}", i, resultFromPdf(i))
    Next i
End Sub

Sub Main(args As String())
    Dim resultFromPdf = BarcodeReader.ReadPdf("Barcode.pdf") ' Scan barcodes from a PDF
    Dim myOptionsExample As New BarcodeReaderOptions() With {
        .Speed = ReadingSpeed.Balanced,
        .ExpectMultipleBarcodes = True,
        .ExpectBarcodeTypes = BarcodeEncoding.AllOneDimensional,
        .Multithreaded = True,
        .MaxParallelThreads = 2,
        .CropArea = New System.Drawing.Rectangle(),
        .UseCode39ExtendedMode = True
    }
    For i As Integer = 0 To resultFromPdf.Count - 1
        Console.WriteLine("Barcode Value - {0} = {1}", i, resultFromPdf(i))
    Next i
End Sub

The above code scans barcodes from a PDF file, "Barcode.pdf." The BarcodeReader.ReadPdf method extracts barcode information from the PDF, and a loop is utilized to iterate through the results. Additionally, the code introduces a BarcodeReaderOptions object, myOptionsExample, configured with various settings such as reading speed, the expectation of multiple barcodes, accepting all one-dimensional barcode types, enabling multithreading with a maximum of two parallel threads, specifying a crop area, and using Code 39 extended mode. These options demonstrate the flexibility of the IronBarcode library in customizing the barcode reading process based on specific requirements and environmental considerations. The barcode values are then printed to the console, providing insights into the decoded data from the PDF file.

The output is displayed as:

In this way, we can create our own .NET barcode scanner DLL.