PSPDFKit GdPicture.NET Library: Best Practices

This guide outlines best practices for working with PSPDFKit GdPicture.NET Library.

Error Handling

Errors in GdPicture.NET are handled using status checks, and GdPicture.NET doesn’t throw exceptions. This is to ensure code compatibility across different programming languages, some of which don’t support exceptions.

The status codes are the members of the GdPictureStatus enumeration. Many GdPicture.NET methods return a member of the GdPictureStatus enumeration that displays the status of the performed operation.

The following code converts a PDF to a TIFF image. The example uses a status check to ensure the source PDF file is correctly loaded before continuing the process:

using GdPictureDocumentConverter gdpictureDocumentConverter = new GdPictureDocumentConverter();
GdPictureStatus status = gdpictureDocumentConverter.LoadFromFile(@"C:\temp\source.pdf",
    GdPicture14.DocumentFormat.DocumentFormatPDF);
if (status == GdPictureStatus.OK)
{
    Console.WriteLine("The PDF file has been loaded successfully.");
    status = gdpictureDocumentConverter.SaveAsTIFF(@"C:\temp\output.tif",
        TiffCompression.TiffCompressionAUTO);
    if (status == GdPictureStatus.OK)
        Console.WriteLine("The file has been saved successfully.");
    else
        Console.WriteLine($"The file has failed to save. Status: {status}");
}
else
    Console.WriteLine($"The file has failed to load. Status: {status}");

Using gdpictureDocumentConverter As GdPictureDocumentConverter = New GdPictureDocumentConverter()
    Dim status As GdPictureStatus = gdpictureDocumentConverter.LoadFromFile("C:\temp\source.pdf",
        GdPicture14.DocumentFormat.DocumentFormatPDF)

    If status Is GdPictureStatus.OK Then
        Console.WriteLine("The PDF file has been loaded successfully.")
        status = gdpictureDocumentConverter.SaveAsTIFF("C:\temp\output.tif",
            TiffCompression.TiffCompressionAUTO)
        If status Is GdPictureStatus.OK Then
            Console.WriteLine("The file has been saved successfully.")
        Else
            Console.WriteLine($"The file has failed to save. Status: {status}")
        End If
    Else
        Console.WriteLine($"The file has failed to load. Status: {status}")
    End If
End Using

Used Methods

Releasing Used Images

After working with an image, release it from memory by passing the image ID to the DisposeImage method of the GdPictureDocumentUtilities class. As DisposeImage is a static method of a static class, you can use it without instantiating the GdPictureDocumentUtilities class. You can call this method on any image, irrespective of how you loaded it:

using GdPicturePDF gdpictureSourcePDF = new GdPicturePDF();
using GdPicturePDF gdpictureDestPDF = new GdPicturePDF();
gdpictureSourcePDF.LoadFromFile(@"C:\temp\source.pdf");
gdpictureDestPDF.NewPDF();
int pageCount = gdpictureSourcePDF.GetPageCount();
int imageCount = gdpictureSourcePDF.GetPageImageCount();
int imageID = 0;
for (int i = 1; i < pageCount; i++)
{
    // Select the next PDF page.
    gdpictureSourcePDF.SelectPage(i);
    imageCount = gdpictureSourcePDF.GetPageImageCount();
    for (int j = 1; j < imageCount; j++)
    {
        // Extract the image from the selected PDF page.
        imageID = gdpictureSourcePDF.ExtractPageImage(j);
        // Add the image to the destination PDF.
        gdpictureDestPDF.AddImageFromGdPictureImage(imageID,
            PdfAdvancedImageCompression.PdfAdvancedImageCompressionMRC);
        // Release the image from memory.
        GdPictureDocumentUtilities.DisposeImage(imageID);
    }
}
gdpictureDestPDF.SaveToFile(@"C:\temp\output.pdf");

Using gdpictureSourcePDF As GdPicturePDF = New GdPicturePDF()
Using gdpictureDestPDF As GdPicturePDF = New GdPicturePDF()
    Dim gdPictureImaging As GdPictureImaging = New GdPictureImaging()
    gdpictureSourcePDF.LoadFromFile("C:\temp\source.pdf")
    gdpictureDestPDF.NewPDF()
    Dim pageCount As Integer = gdpictureSourcePDF.GetPageCount()
    Dim imageCount As Integer = gdpictureSourcePDF.GetPageImageCount()
    Dim imageID = 0

    For i = 1 To pageCount - 1
        ' Select the next PDF page.
        gdpictureSourcePDF.SelectPage(i)
        imageCount = gdpictureSourcePDF.GetPageImageCount()
        For j = 1 To imageCount - 1
            ' Extract the image from the selected PDF page.
            imageID = gdpictureSourcePDF.ExtractPageImage(j)
            ' Add the image to the destination PDF.
            gdpictureDestPDF.AddImageFromGdPictureImage(imageID,
                PdfAdvancedImageCompression.PdfAdvancedImageCompressionMRC)
            ' Release the image from memory.
            GdPictureDocumentUtilities.DisposeImage(imageID)
        Next
    Next

    gdpictureDestPDF.SaveToFile("C:\temp\output.pdf")
End Using
End Using

Used Methods