在本文中,我們將講解如何使用Aspose.BarCode for .NET 和 Aspose.Pdf for .NET從Pdf文檔中識別條碼。

步驟如下:

 1 使用 Aspose.Pdf for .NET從Pdf文檔中提取圖像

2 以流的形式保存提取的圖像

3 將圖像以流的形式傳遞到Aspose.BarCode for .NET

4 從圖像中讀取條碼

C#

try
{
    // set the license for Aspose.BarCode for .NET and Aspose.Pdf for .NET components
    Aspose.BarCodeRecognition.License licenceBarCodeRecognition = new Aspose.BarCodeRecognition.License();
    licenceBarCodeRecognition.SetLicense(@"Aspose.Total.Product.Family.lic");

    Aspose.Pdf.License licensePdf = new Aspose.Pdf.License();
    licensePdf.SetLicense(@"Aspose.Total.Product.Family.lic");

    // bind the pdf document
    Aspose.Pdf.Facades.PdfExtractor pdfExtractor = new Aspose.Pdf.Facades.PdfExtractor();
    pdfExtractor.BindPdf(@"document.pdf");
    // set page range for image extraction
    pdfExtractor.StartPage = 1;
    pdfExtractor.EndPage = 1;
    // extract the images
    Console.WriteLine("Extracting images.....");
    pdfExtractor.ExtractImage();
    // save images to stream in a loop
    while (pdfExtractor.HasNextImage())
    {
        Console.WriteLine("Getting next image....");
        // save image to stream
        MemoryStream imageStream = new MemoryStream();
        pdfExtractor.GetNextImage(imageStream);
        imageStream.Position = 0;

        Console.WriteLine("Recognizing barcode....");
        // recognize the barcode from the image stream above
        Aspose.BarCodeRecognition.BarCodeReader barcodeReader = new Aspose.BarCodeRecognition.BarCodeReader(imageStream, BarCodeReadType.Code39Standard);
        while (barcodeReader.Read())
        {
            Console.WriteLine("Codetext found: " + barcodeReader.GetCodeText() + ", Symbology: " + barcodeReader.GetReadType().ToString());
        }
        // close the reader
        barcodeReader.Close();
    }
}
catch (Exception ex)
{
    Console.WriteLine(ex.Message);
}
 

[VB.NET]

Try
	' set the license for Aspose.BarCode for .NET and Aspose.Pdf for .NET components
	Dim licenceBarCodeRecognition As New Aspose.BarCodeRecognition.License()
	licenceBarCodeRecognition.SetLicense("Aspose.Total.Product.Family.lic")

	Dim licensePdf As New Aspose.Pdf.License()
	licensePdf.SetLicense("Aspose.Total.Product.Family.lic")

	' bind the pdf document
	Dim pdfExtractor As New Aspose.Pdf.Facades.PdfExtractor()
	pdfExtractor.BindPdf("docuemnt.pdf")
	' set page range for image extraction
	pdfExtractor.StartPage = 1
	pdfExtractor.EndPage = 1
	' extract the images
	Console.WriteLine("Extracting images.....")
	pdfExtractor.ExtractImage()
	' save images to stream in a loop
	Do While pdfExtractor.HasNextImage()
		Console.WriteLine("Getting next image....")
		' save image to stream
		Dim imageStream As New MemoryStream()
		pdfExtractor.GetNextImage(imageStream)
		imageStream.Position = 0

		Console.WriteLine("Recognizing barcode....")
		' recognize the barcode from the image stream above
		Dim barcodeReader As New Aspose.BarCodeRecognition.BarCodeReader(imageStream, BarCodeReadType.Code39Standard)
		Do While barcodeReader.Read()
			Console.WriteLine("Codetext found: " & barcodeReader.GetCodeText() & ", Symbology: " & barcodeReader.GetReadType().ToString())
		Loop
		' close the reader
		barcodeReader.Close()
	Loop
Catch ex As Exception
	Console.WriteLine(ex.Message)
End Try