How to Read Multiple Barcodes at Once

By default, IronBarcode continuously scans a document to read multiple barcodes. However, there have been instances where only one barcode value is returned, even when multiple barcodes are present in the image. To address this, users can customize the settings to enable reading multiple barcodes, as shown in the code snippet below. Please note that the ExpectMultipleBarcodes property exists in both the BarcodeReaderOptions and PdfBarcodeReaderOptions classes, allowing users to use it for reading barcodes in both images and PDF documents.

Sample Image

:path=/static-assets/barcode/content-code-examples/how-to/read-multiple-barcodes-read-multiple-barcodes.cs

using IronBarCode;
using System;

// Set the option to read multiple barcodes
BarcodeReaderOptions options = new BarcodeReaderOptions()
{
    ExpectMultipleBarcodes = true,
    ExpectBarcodeTypes = BarcodeEncoding.AllOneDimensional,
};

// Read barcode
var results = BarcodeReader.Read("testbc1.png", options);

foreach (var result in results)
{
    Console.WriteLine(result.ToString());
}

Imports IronBarCode
Imports System

' Set the option to read multiple barcodes
Private options As New BarcodeReaderOptions() With {
	.ExpectMultipleBarcodes = True,
	.ExpectBarcodeTypes = BarcodeEncoding.AllOneDimensional
}

' Read barcode
Private results = BarcodeReader.Read("testbc1.png", options)

For Each result In results
	Console.WriteLine(result.ToString())
Next result

By setting ExpectMultipleBarcodes to true in the code snippet, IronBarcode scans the entire document for multiple barcodes and stores them in the BarcodeResults variable. Using a foreach loop, users can easily access and print all the barcode values to the console.

IronBarcode can read both single and multiple barcodes in an image or PDF. By default, the engine scans the entire document even if there is only one barcode. However, for increased performance when reading a single barcode, you can set ExpectMultipleBarcodes to false. This stops the engine from scanning the entire document after the first barcode is detected, resulting in faster barcode retrieval. The code snippet below demonstrates how to do this.

Sample Image

:path=/static-assets/barcode/content-code-examples/how-to/read-multiple-barcodes-read-single-barcode.cs

using IronBarCode;
using System;

// Set the option to read single barcode
BarcodeReaderOptions options = new BarcodeReaderOptions()
{
    ExpectMultipleBarcodes = false,
    ExpectBarcodeTypes = BarcodeEncoding.AllOneDimensional,
};

// Read barcode
var results = BarcodeReader.Read("testbc1.png", options);

foreach (var result in results)
{
    Console.WriteLine(result.ToString());
}

Imports IronBarCode
Imports System

' Set the option to read single barcode
Private options As New BarcodeReaderOptions() With {
	.ExpectMultipleBarcodes = False,
	.ExpectBarcodeTypes = BarcodeEncoding.AllOneDimensional
}

' Read barcode
Private results = BarcodeReader.Read("testbc1.png", options)

For Each result In results
	Console.WriteLine(result.ToString())
Next result

In the code snippet above, we used the same image with multiple barcodes as before, but this time, we set ExpectMultipleBarcodes to false. As a result, only the first barcode value is returned, and the scanning process stops once the first barcode is retrieved.

Performance Comparison

Setting ExpectMultipleBarcodes to false can greatly improve the efficiency of reading single barcodes in the image.

Using the provided code snippet, here's a rough estimate of the performance difference between setting ExpectMultipleBarcodes to true and false on the same machine: