Manipulate PDF Document in C#

Validate PDF Document for PDF A Standard (A 1A and A 1B)

To validate a PDF document for PDF/A-1a or PDF/A-1b compatibility, use the Document class Validate method. This method allows you to specify the name of the file in which the result is to be saved and the required validation type PdfFormat enumeration : PDF_A_1A or PDF_A_1B.

The output XML format is custom Aspose format. The XML contains a collection of tags with the name Problem; each tag contains the details of a particular problem. The Problem tag’s ObjectID attribute represents the ID of the particular object this problem is related to. The Clause attribute represents a corresponding rule in the PDF specification.

The following code snippet also work with Aspose.PDF.Drawing library.

The following code snippet shows you how to validate PDF document for PDF/A-1A.

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void ValidateToPdfA1aStandard()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "ValidatePDFAStandard.pdf"))
    {
        // Validate PDF for PDF/A-1a
        document.Validate(dataDir + "validation-result-A1A.xml", Aspose.Pdf.PdfFormat.PDF_A_1A);
    }
}

The following code snippet shows you how to validate PDF document for PDF/A-1b.

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void ValidateToPdfA1bStandard()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "ValidatePDFAStandard.pdf"))
    {
        // Validate PDF for PDF/A-1b
        document.Validate(dataDir + "validation-result-A1A.xml", Aspose.Pdf.PdfFormat.PDF_A_1B);
    }
}

Aspose.PDF for .NET can be used to determine if the loaded document is a valid PDF and also if its encrypted or not. In order to further extend the capabilities of Document class, IsPdfaCompliant property is added to determine if the input file is PDF/A compliant and a property named PdfaFormat to identify the PDF/A format are introduced.

Working with TOC

Add TOC to Existing PDF

Aspose.PDF API allows you to add a table of content either when creating a PDF, or to an existing file. The ListSection class in the Aspose.Pdf.Generator namespace allows you to create a table of contents when creating a PDF from scratch. To add headings, which are elements of the TOC, use the Aspose.Pdf.Generator.Heading class.

To add a TOC to an existing PDF file, use the Heading class in the Aspose.PDF namespace. The Aspose.Pdf namespace can both create new and manipulate existing PDF files. To add a TOC to an existing PDF, use the Aspose.PDF namespace. The following code snippet shows how to create a table of contents inside an existing PDF file.

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void AddTOCToPdf()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "AddTOC.pdf"))
    {
        // Get access to the first page of PDF file
        var tocPage = document.Pages.Insert(1);

        // Create an object to represent TOC information
        var tocInfo = new Aspose.Pdf.TocInfo();
        var title = new Aspose.Pdf.Text.TextFragment("Table Of Contents");
        title.TextState.FontSize = 20;
        title.TextState.FontStyle = Aspose.Pdf.Text.FontStyles.Bold;

        // Set the title for TOC
        tocInfo.Title = title;
        tocPage.TocInfo = tocInfo;

        // Create string objects which will be used as TOC elements
        string[] titles = { "First page", "Second page", "Third page", "Fourth page" };

        for (int i = 0; i < 2; i++)
        {
            // Create Heading object
            var heading = new Aspose.Pdf.Heading(1);
            var segment = new Aspose.Pdf.Text.TextSegment();
            heading.TocPage = tocPage;
            heading.Segments.Add(segment);

            // Specify the destination page for the heading object
            heading.DestinationPage = document.Pages[i + 2];

            // Destination page
            heading.Top = document.Pages[i + 2].Rect.Height;

            // Destination coordinate
            segment.Text = titles[i];

            // Add heading to the page containing TOC
            tocPage.Paragraphs.Add(heading);
        }

        // Save PDF document
        document.Save(dataDir + "TOC_out.pdf");
    }
}

Set different TabLeaderType for different TOC Levels

Aspose.PDF also allows setting different TabLeaderType for different TOC levels. You need to set LineDash property of FormatArray with the appropriate value of TabLeaderType enum as following.

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void CreateTocWithCustomFormatting()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Add a TOC page
        var tocPage = document.Pages.Add();

        // Create TOC information
        var tocInfo = new Aspose.Pdf.TocInfo();

        // Set LeaderType
        tocInfo.LineDash = Aspose.Pdf.Text.TabLeaderType.Solid;

        // Set the title for TOC
        var title = new Aspose.Pdf.Text.TextFragment("Table Of Contents");
        title.TextState.FontSize = 30;
        tocInfo.Title = title;

        // Add the TOC section to the document
        tocPage.TocInfo = tocInfo;

        // Define the format of the four levels list by setting the left margins
        // and text format settings of each level
        tocInfo.FormatArrayLength = 4;

        // Level 1
        tocInfo.FormatArray[0].Margin.Left = 0;
        tocInfo.FormatArray[0].Margin.Right = 30;
        tocInfo.FormatArray[0].LineDash = Aspose.Pdf.Text.TabLeaderType.Dot;
        tocInfo.FormatArray[0].TextState.FontStyle = Aspose.Pdf.Text.FontStyles.Bold | Aspose.Pdf.Text.FontStyles.Italic;

        // Level 2
        tocInfo.FormatArray[1].Margin.Left = 10;
        tocInfo.FormatArray[1].Margin.Right = 30;
        tocInfo.FormatArray[1].LineDash = Aspose.Pdf.Text.TabLeaderType.None;
        tocInfo.FormatArray[1].TextState.FontSize = 10;

        // Level 3
        tocInfo.FormatArray[2].Margin.Left = 20;
        tocInfo.FormatArray[2].Margin.Right = 30;
        tocInfo.FormatArray[2].TextState.FontStyle = Aspose.Pdf.Text.FontStyles.Bold;

        // Level 4
        tocInfo.FormatArray[3].LineDash = Aspose.Pdf.Text.TabLeaderType.Solid;
        tocInfo.FormatArray[3].Margin.Left = 30;
        tocInfo.FormatArray[3].Margin.Right = 30;
        tocInfo.FormatArray[3].TextState.FontStyle = Aspose.Pdf.Text.FontStyles.Bold;

        // Create a section in the Pdf document
        var page = document.Pages.Add();

        // Add four headings in the section
        for (int level = 1; level <= 4; level++)
        {
            var heading = new Aspose.Pdf.Heading(level);
            var segment = new Aspose.Pdf.Text.TextSegment();
            heading.Segments.Add(segment);
            heading.IsAutoSequence = true;
            heading.TocPage = tocPage;
            segment.Text = "Sample Heading " + level;
            heading.TextState.Font = Aspose.Pdf.Text.FontRepository.FindFont("Arial Unicode MS");

            // Add the heading into Table Of Contents.
            heading.IsInList = true;
            page.Paragraphs.Add(heading);
        }

        // Save PDF document
        document.Save(dataDir + "TOC_out.pdf");
    }
}

Hide Page Numbers in TOC

In case if you do not want to display page numbers, along with the headings in TOC, you can use IsShowPageNumbers property of TOCInfo Class as false. Please check following code snippet to hide page numbers in the table of contents:

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void CreateTocWithHiddenPageNumbers()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Add a TOC page
        var tocPage = document.Pages.Add();

        // Create TOC information
        var tocInfo = new Aspose.Pdf.TocInfo();

        // Set the title for TOC
        var title = new Aspose.Pdf.Text.TextFragment("Table Of Contents");
        title.TextState.FontSize = 20;
        title.TextState.FontStyle = Aspose.Pdf.Text.FontStyles.Bold;
        tocInfo.Title = title;

        // Add the TOC section to the document
        tocPage.TocInfo = tocInfo;

        // Hide page numbers in TOC
        tocInfo.IsShowPageNumbers = false;

        // Define the format of the four levels list by setting the left margins and
        // text format settings of each level
        tocInfo.FormatArrayLength = 4;

        // Level 1
        tocInfo.FormatArray[0].Margin.Right = 0;
        tocInfo.FormatArray[0].TextState.FontStyle = Aspose.Pdf.Text.FontStyles.Bold | Aspose.Pdf.Text.FontStyles.Italic;

        // Level 2
        tocInfo.FormatArray[1].Margin.Left = 30;
        tocInfo.FormatArray[1].TextState.Underline = true;
        tocInfo.FormatArray[1].TextState.FontSize = 10;

        // Level 3
        tocInfo.FormatArray[2].TextState.FontStyle = Aspose.Pdf.Text.FontStyles.Bold;

        // Level 4
        tocInfo.FormatArray[3].TextState.FontStyle = Aspose.Pdf.Text.FontStyles.Bold;

        // Create a section in the Pdf document
        var page = document.Pages.Add();

        // Add four headings in the section
        for (int level = 1; level <= 4; level++)
        {
            var heading = new Aspose.Pdf.Heading(level);
            var segment = new Aspose.Pdf.Text.TextSegment();
            heading.TocPage = tocPage;
            heading.Segments.Add(segment);
            heading.IsAutoSequence = true;
            segment.Text = "this is heading of level " + level;
            heading.IsInList = true;
            page.Paragraphs.Add(heading);
        }

        // Save PDF document
        document.Save(dataDir + "TOC_out.pdf");
    }
}

Customize Page Numbers while adding TOC

It is common to customize the page numbering in the TOC while adding TOC in a PDF document. For example, we may need to add some prefix before page number like P1, P2, P3 and so on. In such a case, Aspose.PDF for .NET provides PageNumbersPrefix property of TocInfo class that can be used to customize page numbers as shown in the following code sample.

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void CustomizePageNumbersAddingToC()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "CustomizePageNumbersAddingToC.pdf"))
    {
        // Get access to first page of PDF file
        Page tocPage = document.Pages.Insert(1);

        // Create object to represent TOC information
        var tocInfo = new Aspose.Pdf.TocInfo();
        var title = new Aspose.Pdf.Text.TextFragment("Table Of Contents");
        title.TextState.FontSize = 20;
        title.TextState.FontStyle = Aspose.Pdf.Text.FontStyles.Bold;

        // Set the title for TOC
        tocInfo.Title = title;
        tocInfo.PageNumbersPrefix = "P";
        tocPage.TocInfo = tocInfo;

        // Loop through the pages to create TOC entries
        for (int i = 1; i < document.Pages.Count; i++)
        {
            // Create Heading object
            var heading2 = new Aspose.Pdf.Heading(1);
            var segment2 = new Aspose.Pdf.Text.TextSegment();
            heading2.TocPage = tocPage;
            heading2.Segments.Add(segment2);

            // Specify the destination page for heading object
            heading2.DestinationPage = document.Pages[i + 1];

            // Destination page
            heading2.Top = document.Pages[i + 1].Rect.Height;

            // Destination coordinate
            segment2.Text = "Page " + i.ToString();

            // Add heading to page containing TOC
            tocPage.Paragraphs.Add(heading2);
        }

        // Save PDF document
        document.Save(dataDir + "CustomizePageNumbersAddingToC_out.pdf");
    }
}

How to set PDF expiry date

We apply access privileges on PDF files so that a certain group of users can access particular features/objects of PDF documents. In order to restrict the PDF file access, we usually apply encryption and we may have a requirement to set PDF file expiration, so that the user accessing/viewing the document gets a valid prompt regarding PDF file expiry.

In order to accomplish the above stated requirement, we can use JavascriptAction object. Please take a look over the following code snippet.

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void SetExpiryDate()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Add page
        var page = document.Pages.Add();

        // Add text fragment to paragraphs collection of page object
        page.Paragraphs.Add(new Aspose.Pdf.Text.TextFragment("Hello World..."));

        // Create JavaScript object to set PDF expiry date
        var javaScript = new Aspose.Pdf.Annotations.JavascriptAction(
            "var year=2017;" +
            "var month=5;" +
            "today = new Date(); today = new Date(today.getFullYear(), today.getMonth());" +
            "expiry = new Date(year, month);" +
            "if (today.getTime() > expiry.getTime())" +
            "app.alert('The file is expired. You need a new one.');"
        );

        // Set JavaScript as PDF open action
        document.OpenAction = javaScript;

        // Save PDF Document
        document.Save(dataDir + "SetExpiryDate_out.pdf");
    }
}

Determine Progress of PDF File Generation

A customer asked us to add a feature that allows developers to determine the progress of PDF file generation. Here’s the response to that request.

The field CustomerProgressHandler of DocSaveOptions class allows you to determine how PDF generation is going. The handler has the following types:

DocSaveOptions.ConversionProgessEventHandler.
DocSaveOptions.ProgressEventHandlerInfo.
DocSaveOptions.ProgressEventType.

The code snippets below shows how to use CustomerProgressHandler.

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void DetermineProgress()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "AddTOC.pdf"))
    {
        // Create DocSaveOptions instance and set custom progress handler
        var saveOptions = new Aspose.Pdf.DocSaveOptions();
        saveOptions.CustomProgressHandler = new Aspose.Pdf.UnifiedSaveOptions.ConversionProgressEventHandler(ShowProgressOnConsole);

        // Save PDF Document
        document.Save(dataDir + "DetermineProgress_out.pdf", saveOptions);
    }
}

// Method to handle progress and display it on the console
private static void ShowProgressOnConsole(Aspose.Pdf.UnifiedSaveOptions.ProgressEventHandlerInfo eventInfo)
{
    switch (eventInfo.EventType)
    {
        case Aspose.Pdf.ProgressEventType.TotalProgress:
            Console.WriteLine(String.Format("{0}  - Conversion progress : {1}% .", DateTime.Now.ToLongTimeString(), eventInfo.Value.ToString()));
            break;
        case Aspose.Pdf.ProgressEventType.SourcePageAnalysed:
            Console.WriteLine(String.Format("{0}  - Source page {1} of {2} analyzed.", DateTime.Now.ToLongTimeString(), eventInfo.Value.ToString(), eventInfo.MaxValue.ToString()));
            break;
        case Aspose.Pdf.ProgressEventType.ResultPageCreated:
            Console.WriteLine(String.Format("{0}  - Result page's {1} of {2} layout created.", DateTime.Now.ToLongTimeString(), eventInfo.Value.ToString(), eventInfo.MaxValue.ToString()));
            break;
        case Aspose.Pdf.ProgressEventType.ResultPageSaved:
            Console.WriteLine(String.Format("{0}  - Result page {1} of {2} exported.", DateTime.Now.ToLongTimeString(), eventInfo.Value.ToString(), eventInfo.MaxValue.ToString()));
            break;
        default:
            break;
    }
}

Flatten Fillable PDF

PDF documents often include forms with interactive fillable widgets such as radio buttons, checkboxes, text boxes, lists, etc. To make it uneditable for various application purposes, we need to flatten the PDF file. Aspose.PDF provides the function to flatten your PDF in C# with just few line of code:

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void FlattenForms()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "input.pdf"))
    {
        // Flatten Fillable PDF
        if (document.Form.Fields.Count() > 0)
        {
            foreach (var item in document.Form.Fields)
            {
                item.Flatten();
            }
        }

        // Save PDF document
        document.Save(dataDir + "FlattenForms_out.pdf");
    }
}

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