How to Use Barcode Scanners in C# Windows Apps

1. Package Manager Console

Write the following command in the Package Manager Console. It will download and install the package for you.

Install-Package BarCode

2. NuGet Packages Manager Solution

You can also install the Barcode Library by using the NuGet Package Solution. Simply follow these steps:

Click on Tools > NuGet Package Manager > Manage NuGet Packages for Solution.

This will open NuGet Package Manager for you. Click on Browse and search for Barcode, then install the class library.

3. Download from the Link

As an alternative, the IronBarCode.Dll can be downloaded and added to your project as a reference.

After downloading, add the following references to your barcode reader project.

using IronBarCode;

using IronBarCode;

Imports IronBarCode

Barcode Scanner

In your project, browse for the image you wish to read. It will open in PictureBox; now click on "scan code". The text will appear in the text box.

Here is the code for the "browse" button to open an image:

// Open file dialog   
OpenFileDialog open = new OpenFileDialog();
// Image filters  
open.Filter = "Image Files(*.jpg; *.png; *.jpeg; *.gif; *.bmp)|*.jpg;*.png;*.jpeg;*.gif;*.bmp";
if (open.ShowDialog() == DialogResult.OK) {  
    // Display image in PictureBox
    pictureBox1.Image = new Bitmap(open.FileName); 
    // Store image file path in class data member. Initialize it as string ImageFileName;
    ImageFileName = open.FileName; 
}

// Open file dialog   
OpenFileDialog open = new OpenFileDialog();
// Image filters  
open.Filter = "Image Files(*.jpg; *.png; *.jpeg; *.gif; *.bmp)|*.jpg;*.png;*.jpeg;*.gif;*.bmp";
if (open.ShowDialog() == DialogResult.OK) {  
    // Display image in PictureBox
    pictureBox1.Image = new Bitmap(open.FileName); 
    // Store image file path in class data member. Initialize it as string ImageFileName;
    ImageFileName = open.FileName; 
}

' Open file dialog   
Dim open As New OpenFileDialog()
' Image filters  
open.Filter = "Image Files(*.jpg; *.png; *.jpeg; *.gif; *.bmp)|*.jpg;*.png;*.jpeg;*.gif;*.bmp"
If open.ShowDialog() = DialogResult.OK Then
	' Display image in PictureBox
	pictureBox1.Image = New Bitmap(open.FileName)
	' Store image file path in class data member. Initialize it as string ImageFileName;
	ImageFileName = open.FileName
End If

The code for the "scan code" button:

// Read the barcode from the image file path
BarcodeResult Result = BarcodeReader.Read(ImageFileName);
// Display the decoded text in TextBox
textBox1.Text = Result.Text;

// Read the barcode from the image file path
BarcodeResult Result = BarcodeReader.Read(ImageFileName);
// Display the decoded text in TextBox
textBox1.Text = Result.Text;

' Read the barcode from the image file path
Dim Result As BarcodeResult = BarcodeReader.Read(ImageFileName)
' Display the decoded text in TextBox
textBox1.Text = Result.Text

The barcode scanner displays the barcode data in the text box as follows:

Barcode Image to be Scanned with C#

QR Code Scanner

In this section, the IronBarcode Library effectively handles real-world situations involving skewed QR codes. Although the skewed angle QR code can be handled and read by the Read method, it can nevertheless take more time to resolve. The IronBarcode library provides a customized way of using BarcodeReaderOptions as an extra parameter to deal with such image input. The code goes as follows:

// Define a collection of image filters to apply
var filtersToApply = new ImageFilterCollection() {
    new SharpenFilter(),
    new InvertFilter(),
    new ContrastFilter(),
    new BrightnessFilter(),
    new AdaptiveThresholdFilter(),
    new BinaryThresholdFilter()
};

// Configure barcode reader options with specified filters
BarcodeReaderOptions myOptionsExample = new BarcodeReaderOptions() {
    ImageFilters = filtersToApply,
    ExpectBarcodeTypes = BarcodeEncoding.QRCode | BarcodeEncoding.Code128,
};

// Read the barcode/QR code with custom options and display result
BarcodeResult Result = BarcodeReader.Read(ImageFileName, myOptionsExample);
textBox1.Text = Result.Text;

// Define a collection of image filters to apply
var filtersToApply = new ImageFilterCollection() {
    new SharpenFilter(),
    new InvertFilter(),
    new ContrastFilter(),
    new BrightnessFilter(),
    new AdaptiveThresholdFilter(),
    new BinaryThresholdFilter()
};

// Configure barcode reader options with specified filters
BarcodeReaderOptions myOptionsExample = new BarcodeReaderOptions() {
    ImageFilters = filtersToApply,
    ExpectBarcodeTypes = BarcodeEncoding.QRCode | BarcodeEncoding.Code128,
};

// Read the barcode/QR code with custom options and display result
BarcodeResult Result = BarcodeReader.Read(ImageFileName, myOptionsExample);
textBox1.Text = Result.Text;

' Define a collection of image filters to apply
Dim filtersToApply = New ImageFilterCollection() From {
	New SharpenFilter(),
	New InvertFilter(),
	New ContrastFilter(),
	New BrightnessFilter(),
	New AdaptiveThresholdFilter(),
	New BinaryThresholdFilter()
}

' Configure barcode reader options with specified filters
Dim myOptionsExample As New BarcodeReaderOptions() With {
	.ImageFilters = filtersToApply,
	.ExpectBarcodeTypes = BarcodeEncoding.QRCode Or BarcodeEncoding.Code128
}

' Read the barcode/QR code with custom options and display result
Dim Result As BarcodeResult = BarcodeReader.Read(ImageFileName, myOptionsExample)
textBox1.Text = Result.Text

The output will be as follows after opening the skewed QR code image:

Skewed QrCode Image

PDF Documents

Barcode images can be scanned from a PDF file, and each result can be displayed appropriately as desired. The following sample code allows you to read multiple barcodes from a PDF file.

// Scan for multiple barcodes within a PDF document
BarcodeResult[] PDFResults = BarcodeReader.ReadPdf("MultipleBarcodes.pdf");

// Work with the results found
foreach (var PageResult in PDFResults) { 
    string Value = PageResult.Value;
    int PageNum = PageResult.PageNumber;
    System.Drawing.Bitmap Img = PageResult.BarcodeImage;
    BarcodeEncoding BarcodeType = PageResult.BarcodeType;
    byte[] Binary = PageResult.BinaryValue;
    Console.WriteLine(PageResult.Value + " on page " + PageNum);
}

// Scan for multiple barcodes within a PDF document
BarcodeResult[] PDFResults = BarcodeReader.ReadPdf("MultipleBarcodes.pdf");

// Work with the results found
foreach (var PageResult in PDFResults) { 
    string Value = PageResult.Value;
    int PageNum = PageResult.PageNumber;
    System.Drawing.Bitmap Img = PageResult.BarcodeImage;
    BarcodeEncoding BarcodeType = PageResult.BarcodeType;
    byte[] Binary = PageResult.BinaryValue;
    Console.WriteLine(PageResult.Value + " on page " + PageNum);
}

' Scan for multiple barcodes within a PDF document
Dim PDFResults() As BarcodeResult = BarcodeReader.ReadPdf("MultipleBarcodes.pdf")

' Work with the results found
For Each PageResult In PDFResults
	Dim Value As String = PageResult.Value
	Dim PageNum As Integer = PageResult.PageNumber
	Dim Img As System.Drawing.Bitmap = PageResult.BarcodeImage
	Dim BarcodeType As BarcodeEncoding = PageResult.BarcodeType
	Dim Binary() As Byte = PageResult.BinaryValue
	Console.WriteLine(PageResult.Value & " on page " & PageNum)
Next PageResult

Barcode and QR code present in PDF files:

C# - Reading Barcodes from a PDF results

Thumbnails

The IronBarcode Library uses the C# Barcode Generator, which is even capable of reading a corrupted thumbnail of a barcode.

Automatic barcode thumbnail size correction. File readable using IronBarcode in C#

It automatically detects barcode images that are too small to reasonably represent an actual barcode, and then upscales and cleans all of the digital noise associated with thumbnailing, thereby allowing them to be readable again.

// Small or 'Thumbnail' barcode images are automatically detected by IronBarCode and corrected for wherever possible even if they have much digital noise.
BarcodeResult SmallResult = BarcodeReader.Read("ThumbnailOfBarcode.gif");

// Small or 'Thumbnail' barcode images are automatically detected by IronBarCode and corrected for wherever possible even if they have much digital noise.
BarcodeResult SmallResult = BarcodeReader.Read("ThumbnailOfBarcode.gif");

' Small or 'Thumbnail' barcode images are automatically detected by IronBarCode and corrected for wherever possible even if they have much digital noise.
Dim SmallResult As BarcodeResult = BarcodeReader.Read("ThumbnailOfBarcode.gif")