Working with Hyperlinks

1 Jan 202324 minutes to read

In PDF, hyperlinks can be added to allow the users to navigate to another part of PDF file, web page or any other external content. Essential PDF provides support for all these types of hyperlink.

Working with Web navigation

You can navigate to specified URL from a PDF document by using the PdfTextWebLink class.

Please refer the below code snippet for navigating to the web page.

//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Add a page to the document.
PdfPage page = document.Pages.Add();
//Create the font.
PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 12f);

//Create the Text Web Link.
PdfTextWebLink textLink = new PdfTextWebLink();
//Set the hyperlink.
textLink.Url = "http://www.syncfusion.com";
//Set the link text.
textLink.Text = "Syncfusion .NET components and controls";
//Set the font.
textLink.Font = font;
//Draw the hyperlink in PDF page.
textLink.DrawTextWebLink(page, new PointF(10, 40));

//Save the document.
document.Save("Output.pdf");
//Close the document.
document.Close(true);
'Create a new PDF document.
Dim document As New PdfDocument()
'Add a page to the document.
Dim page As PdfPage = document.Pages.Add()
'Create the font.
Dim font As PdfFont = New PdfStandardFont(PdfFontFamily.Helvetica, 12.0F)

'Create the Text Web Link.
Dim textLink As New PdfTextWebLink()
'Add the hyperlink.
textLink.Url = "http://www.syncfusion.com"
'Set the link text.
textLink.Text = "Syncfusion .NET components and controls"
'Set the font.
textLink.Font = font
'Draw the hyperlink in  PDF page.
textLink.DrawTextWebLink(loadedPage.Graphics, New PointF(10, 40))

'Save the document.
document.Save("Output.pdf")
'Close the document.
document.Close(True)
//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Add a page to the document.
PdfPage page = document.Pages.Add();
//Create the font.
PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 12f);

//Create the Text Web Link.
PdfTextWebLink textLink = new PdfTextWebLink();
//Set the hyperlink.
textLink.Url = "http://www.syncfusion.com";
//Set the link text.
textLink.Text = "Syncfusion .NET components and controls";
//Set the font.
textLink.Font = font;
//Draw the hyperlink in PDF page.
textLink.DrawTextWebLink(page, new PointF(10, 40));

//Save the PDF document to stream.
MemoryStream stream = new MemoryStream();
await document.SaveAsync(stream);
//Close the document.
document.Close(true);
//Save the stream as PDF document file in local machine. Refer to PDF/UWP section for respected code samples.
Save(stream, "Output.pdf");
//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Add a page to the document.
PdfPage page = document.Pages.Add();
//Create the font.
PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 12f);

//Create the Text Web Link.
PdfTextWebLink textLink = new PdfTextWebLink();
//Set the hyperlink.
textLink.Url = "http://www.syncfusion.com";
//Set the link text.
textLink.Text = "Syncfusion .NET components and controls";
//Set the font.
textLink.Font = font;
//Draw the hyperlink in PDF page.
textLink.DrawTextWebLink(page, new PointF(10, 40));

//Save the document into stream.
MemoryStream stream = new MemoryStream();
document.Save(stream);
//Set the position as '0'.
stream.Position = 0;
//Close the document.
document.Close(true);
//Defining the ContentType for pdf file.
string contentType = "application/pdf";
//Define the file name.
string fileName = "Output.pdf";
//Creates a FileContentResult object by using the file contents, content type, and file name.
return File(stream, contentType, fileName);
//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Add a page to the document.
PdfPage page = document.Pages.Add();
//Create the font.
PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 12f);

//Create the Text Web Link.
PdfTextWebLink textLink = new PdfTextWebLink();
//Set the hyperlink.
textLink.Url = "http://www.syncfusion.com";
//Set the link text.
textLink.Text = "Syncfusion .NET components and controls";
//Set the font.
textLink.Font = font;
//Draw the hyperlink in PDF page.
textLink.DrawTextWebLink(page, new PointF(10, 40));

//Save the PDF document to stream.
MemoryStream stream = new MemoryStream();
document.Save(stream);
//Closes the document.
document.Close(true);
//Save the stream into pdf file.
//The operation in Save under Xamarin varies between Windows Phone, Android and iOS platforms. Please refer PDF/Xamarin section for respective code samples.
if (Device.OS == TargetPlatform.WinPhone || Device.OS == TargetPlatform.Windows)
{
    Xamarin.Forms.DependencyService.Get<ISaveWindowsPhone>().Save("Output.pdf", "application/pdf", stream);
}
else
{
    Xamarin.Forms.DependencyService.Get<ISave>().Save("Output.pdf", "application/pdf", stream);
}

You can download a complete working sample from GitHub.

To add a web hyperlink to an existing document, please refer the below code snippet.

//Load the existing PDF document.
PdfLoadedDocument loadedDocument = new PdfLoadedDocument(@"Filename.pdf");
//Load the page.
PdfLoadedPage loadedPage = loadedDocument.Pages[0] as PdfLoadedPage;
//Create the font.
PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 12f);

//Create the Text Web Link.
PdfTextWebLink textLink = new PdfTextWebLink();
//Set the hyperlink.
textLink.Url = "http://www.syncfusion.com";
//Set the link text.
textLink.Text = "Syncfusion .NET components and controls";
//Set the font.
textLink.Font = font;
//Draw the hyperlink in loaded page graphics.
textLink.DrawTextWebLink(loadedPage.Graphics, new PointF(10, 40));

//Save the document.
loadedDocument.Save("Output.pdf");
//Close the document.
loadedDocument.Close(true);
'Load the existing PDF document.
Dim loadedDocument As New PdfLoadedDocument("fileName.pdf")
'Load the page.
Dim loadedPage As PdfLoadedPage = TryCast(loadedDocument.Pages(0), PdfLoadedPage)
'Create the font.
Dim font As PdfFont = New PdfStandardFont(PdfFontFamily.Helvetica, 12.0F)

'Create the Text Web Link.
Dim textLink As New PdfTextWebLink()
'Add the hyperlink.
textLink.Url = "http://www.syncfusion.com"
'Set the link text.
textLink.Text = "Syncfusion .NET components and controls"
'Set the font.
textLink.Font = font
'Draw the hyperlink in loaded page graphics.
textLink.DrawTextWebLink(loadedPage.Graphics, New PointF(10, 40))

'Save the document.
loadedDocument.Save("Output1.pdf")
'Close the document.
loadedDocument.Close(True)
//Create the file open picker.
var picker = new FileOpenPicker();
picker.FileTypeFilter.Add(".pdf");
//Browse and chose the file.
StorageFile file = await picker.PickSingleFileAsync();
//Creates an empty PDF loaded document instance.
PdfLoadedDocument loadedDocument = new PdfLoadedDocument();
//Loads or opens an existing PDF document through Open method of PdfLoadedDocument class.
await loadedDocument.OpenAsync(file);
//Load the page.
PdfLoadedPage loadedPage = loadedDocument.Pages[0] as PdfLoadedPage;
//Create the font.
PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 12f);

//Create the Text Web Link.
PdfTextWebLink textLink = new PdfTextWebLink();
//Set the hyperlink.
textLink.Url = "http://www.syncfusion.com";
//Set the link text.
textLink.Text = "Syncfusion .NET components and controls";
//Set the font.
textLink.Font = font;
//Draw the hyperlink in loaded page graphics.
textLink.DrawTextWebLink(loadedPage.Graphics, new PointF(10, 40));

//Save the PDF document to stream.
MemoryStream stream = new MemoryStream();
await loadedDocument.SaveAsync(stream);
//Close the document.
loadedDocument.Close(true);
//Save the stream as PDF document file in local machine. Refer to PDF/UWP section for respected code samples.
Save(stream, "Output.pdf");
//Load the PDF document.
FileStream docStream = new FileStream(fileName, FileMode.Open, FileAccess.Read);
PdfLoadedDocument loadedDocument = new PdfLoadedDocument(docStream);
//Load the page.
PdfLoadedPage loadedPage = loadedDocument.Pages[0] as PdfLoadedPage;
//Create the font.
PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 12f);

//Create the Text Web Link.
PdfTextWebLink textLink = new PdfTextWebLink();
//Set the hyperlink.
textLink.Url = "http://www.syncfusion.com";
//Set the link text.
textLink.Text = "Syncfusion .NET components and controls";
//Set the font.
textLink.Font = font;
//Draw the hyperlink in loaded page graphics.
textLink.DrawTextWebLink(loadedPage.Graphics, new PointF(10, 40));

//Save the document into stream.
MemoryStream stream = new MemoryStream();
loadedDocument.Save(stream);
//Set the position as '0'.
stream.Position = 0;
//Close the document.
loadedDocument.Close(true);
//Defining the ContentType for pdf file.
string contentType = "application/pdf";
//Define the file name.
string fileName = "Output.pdf";
//Creates a FileContentResult object by using the file contents, content type, and file name.
return File(stream, contentType, fileName);
//Load the PDF document.
FileStream docStream = new FileStream(fileName, FileMode.Open, FileAccess.Read);
PdfLoadedDocument loadedDocument = new PdfLoadedDocument(docStream);
//Load the page.
PdfLoadedPage loadedPage = loadedDocument.Pages[0] as PdfLoadedPage;
//Create the font.
PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 12f);

//Create the Text Web Link.
PdfTextWebLink textLink = new PdfTextWebLink();
//Set the hyperlink.
textLink.Url = "http://www.syncfusion.com";
//Set the link text.
textLink.Text = "Syncfusion .NET components and controls";
//Set the font.
textLink.Font = font;
//Draw the hyperlink in loaded page graphics.
textLink.DrawTextWebLink(loadedPage.Graphics, new PointF(10, 40));

//Save the document into stream.
MemoryStream stream = new MemoryStream();
loadedDocument.Save(stream);
//Set the position as '0'.
stream.Position = 0;
//Close the document.
loadedDocument.Close(true);
//Defining the ContentType for pdf file.
string contentType = "application/pdf";
//Define the file name.
string fileName = "Output.pdf";
//Creates a FileContentResult object by using the file contents, content type, and file name.
return File(stream, contentType, fileName);

You can download a complete working sample from GitHub.

Working with internal document navigation

To allow the users to navigate to any other part of the same document, PdfDocumentLinkAnnotation class can be used. The below code explains how to add the hyperlink for internal document navigation.

//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Create a new page. 
PdfPage page = document.Pages.Add();
//Create a new rectangle.
RectangleF docLinkAnnotationBounds = new RectangleF(10, 40, 30, 30);

//Create a new document link annotation.
PdfDocumentLinkAnnotation documentLinkAnnotation = new PdfDocumentLinkAnnotation(docLinkAnnotationBounds);
//Set the annotation flags.
documentLinkAnnotation.AnnotationFlags = PdfAnnotationFlags.NoRotate;
//Set the annotation text.
documentLinkAnnotation.Text = "Document link annotation";
//Set the annotation's color.
documentLinkAnnotation.Color = new PdfColor(Color.Navy);
//Creates another page.
PdfPage navigationPage = document.Pages.Add();
//Set the destination.
documentLinkAnnotation.Destination = new PdfDestination(navigationPage);
//Set the document link annotation location.
documentLinkAnnotation.Destination.Location = new Point(10, 0);
//Set the document annotation zoom level.
documentLinkAnnotation.Destination.Zoom = 5;
//Add this annotation to a new page.
page.Annotations.Add(documentLinkAnnotation);

//Save the document to disk.
document.Save("DocumentLinkAnnotation.pdf");
//Close the document.
document.Close();
'Create a new PDF document.
Dim document As New PdfDocument()
'Create a new page. 
Dim page As PdfPage = document.Pages.Add()
'Create a new rectangle.
Dim docLinkAnnotationBounds As New RectangleF(10, 40, 30, 30)

'Create a new document link annotation.
Dim documentLinkAnnotation As New PdfDocumentLinkAnnotation(docLinkAnnotationBounds)
'Set the annotation flags.
documentLinkAnnotation.AnnotationFlags = PdfAnnotationFlags.NoRotate
'Set the annotation text.
documentLinkAnnotation.Text = "Document link annotation"
'Set the annotation's color.
documentLinkAnnotation.Color = New PdfColor(Color.Navy)
'Create another page.
Dim navigationPage As PdfPage = document.Pages.Add()
'Set the destination.
documentLinkAnnotation.Destination = New PdfDestination(navigationPage)
'Set the document link annotation location.
documentLinkAnnotation.Destination.Location = New Point(10, 0)
'Set the document annotation zoom level.
documentLinkAnnotation.Destination.Zoom = 5
'Add this annotation to a new page.
page.Annotations.Add(documentLinkAnnotation)

'Save the document to disk.
document.Save("DocumentLinkAnnotation.pdf")
'Close the document.
document.Close()
//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Create a new page. 
PdfPage page = document.Pages.Add();
//Create a new rectangle.
RectangleF docLinkAnnotationBounds = new RectangleF(10, 40, 30, 30);

//Create a new document link annotation.
PdfDocumentLinkAnnotation documentLinkAnnotation = new PdfDocumentLinkAnnotation(docLinkAnnotationBounds);
//Set the annotation flags.
documentLinkAnnotation.AnnotationFlags = PdfAnnotationFlags.NoRotate;
//Set the annotation text.
documentLinkAnnotation.Text = "Document link annotation";
//Set the annotation's color.
documentLinkAnnotation.Color = new PdfColor(System.Drawing.Color.FromArgb(0, 0, 0, 128));
//Creates another page. 
PdfPage navigationPage = document.Pages.Add();
//Set the destination.
documentLinkAnnotation.Destination = new PdfDestination(navigationPage);
//Set the document link annotation location.
documentLinkAnnotation.Destination.Location = new PointF(10, 0);
//Set the document annotation zoom level.
documentLinkAnnotation.Destination.Zoom = 5;
//Add this annotation to a new page.
page.Annotations.Add(documentLinkAnnotation);

//Save the PDF document to stream.
MemoryStream stream = new MemoryStream();
await document.SaveAsync(stream);
//Close the document.
document.Close(true);
//Save the stream as PDF document file in local machine. Refer to PDF/UWP section for respected code samples.
Save(stream, "DocumentLinkAnnotation.pdf");
//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Create a new page. 
PdfPage page = document.Pages.Add();
//Create a new rectangle.
RectangleF docLinkAnnotationBounds = new RectangleF(10, 40, 30, 30);

//Create a new document link annotation.
PdfDocumentLinkAnnotation documentLinkAnnotation = new PdfDocumentLinkAnnotation(docLinkAnnotationBounds);
//Set the annotation flags.
documentLinkAnnotation.AnnotationFlags = PdfAnnotationFlags.NoRotate;
//Set the annotation text.
documentLinkAnnotation.Text = "Document link annotation";
//Set the annotation's color.
documentLinkAnnotation.Color = new PdfColor(Color.Navy);
//Creates another page. 
PdfPage navigationPage = document.Pages.Add();
//Set the destination.
documentLinkAnnotation.Destination = new PdfDestination(navigationPage);
//Set the document link annotation location.
documentLinkAnnotation.Destination.Location = new PointF(10, 0);
//Set the document annotation zoom level.
documentLinkAnnotation.Destination.Zoom = 5;
//Add this annotation to a new page.
page.Annotations.Add(documentLinkAnnotation);

//Save the document into stream.
MemoryStream stream = new MemoryStream();
document.Save(stream);
//Set the position as '0'.
stream.Position = 0;
//Close the document.
document.Close(true);
//Defining the ContentType for pdf file.
string contentType = "application/pdf";
//Define the file name.
string fileName = "DocumentLinkAnnotation.pdf";
//Creates a FileContentResult object by using the file contents, content type, and file name.
return File(stream, contentType, fileName);
//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Create a new page. 
PdfPage page = document.Pages.Add();
//Create a new rectangle.
RectangleF docLinkAnnotationBounds = new RectangleF(10, 40, 30, 30);

//Create a new document link annotation.
PdfDocumentLinkAnnotation documentLinkAnnotation = new PdfDocumentLinkAnnotation(docLinkAnnotationBounds);
//Set the annotation flags.
documentLinkAnnotation.AnnotationFlags = PdfAnnotationFlags.NoRotate;
//Set the annotation text.
documentLinkAnnotation.Text = "Document link annotation";
//Set the annotation's color.
documentLinkAnnotation.Color = new PdfColor(Syncfusion.Drawing.Color.Navy);
//Creates another page. 
PdfPage navigationPage = document.Pages.Add();
//Set the destination.
documentLinkAnnotation.Destination = new PdfDestination(navigationPage);
//Set the document link annotation location.
documentLinkAnnotation.Destination.Location = new PointF(10, 0);
//Set the document annotation zoom level.
documentLinkAnnotation.Destination.Zoom = 5;
//Add this annotation to a new page.
page.Annotations.Add(documentLinkAnnotation);

//Save the PDF document to stream.
MemoryStream stream = new MemoryStream();
document.Save(stream);
//Close the document.
document.Close(true);
//Save the stream into pdf file.
//The operation in Save under Xamarin varies between Windows Phone, Android and iOS platforms. Please refer PDF/Xamarin section for respective code samples.
if (Device.OS == TargetPlatform.WinPhone || Device.OS == TargetPlatform.Windows)
{
    Xamarin.Forms.DependencyService.Get<ISaveWindowsPhone>().Save("DocumentLinkAnnotation.pdf", "application/pdf", stream);
}
else
{
    Xamarin.Forms.DependencyService.Get<ISave>().Save("DocumentLinkAnnotation.pdf", "application/pdf", stream);
}

You can download a complete working sample from GitHub.

To add a PdfDocumentLinkAnnotation to an existing document, please use the below code snippet.

//Load the existing PDF document.
PdfLoadedDocument loadedDocument = new PdfLoadedDocument(@"fileName.pdf");
//Load the page.
PdfLoadedPage loadedPage = loadedDocument.Pages[0] as PdfLoadedPage;
//Create a new rectangle.
RectangleF docLinkAnnotationBounds = new RectangleF(10, 40, 30, 30);

//Create a new document link annotation.
PdfDocumentLinkAnnotation documentLinkAnnotation = new PdfDocumentLinkAnnotation(docLinkAnnotationBounds);
//Set the annotation text.
documentLinkAnnotation.Text = "Document link annotation";
//Set the existing page for navigation.
PdfLoadedPage navigationPage = loadedDocument.Pages[1] as PdfLoadedPage;
//Set the pdf destination.
documentLinkAnnotation.Destination = new PdfDestination(navigationPage);
//Set the document link annotation location.
documentLinkAnnotation.Destination.Location = new Point(10, 0);
//Add this annotation to respective page.
loadedPage.Annotations.Add(documentLinkAnnotation);

//Save the document to disk.
loadedDocument.Save("DocumentLinkAnnotation.pdf");
//Close the document.
loadedDocument.Close();
'Load the existing PDF document.
Dim loadedDocument As New PdfLoadedDocument("fileName.pdf")
'Load the page.
Dim loadedPage As PdfLoadedPage = TryCast(loadedDocument.Pages(0), PdfLoadedPage)
'Create a new rectangle.
Dim docLinkAnnotationBounds As New RectangleF(10, 40, 30, 30)

'Create a new document link annotation.
Dim documentLinkAnnotation As New PdfDocumentLinkAnnotation(docLinkAnnotationBounds)
'Set the annotation text.
documentLinkAnnotation.Text = "Document link annotation"
'Set the existing page for navigation.
Dim navigationPage As PdfLoadedPage = TryCast(loadedDocument.Pages(1), PdfLoadedPage)
'Set the pdf destination.
documentLinkAnnotation.Destination = New PdfDestination(navigationPage)
'Set the document link annotation location.
documentLinkAnnotation.Destination.Location = New Point(10, 0)
'Add this annotation to respective page.
loadedPage.Annotations.Add(documentLinkAnnotation)

'Save the document to disk.
loadedDocument.Save("DocumentLinkAnnotation.pdf")
'Close the document.
loadedDocument.Close()
//Create the file open picker.
var picker = new FileOpenPicker();
picker.FileTypeFilter.Add(".pdf");
//Browse and chose the file.
StorageFile file = await picker.PickSingleFileAsync();
//Creates an empty PDF loaded document instance.
PdfLoadedDocument loadedDocument = new PdfLoadedDocument();
//Loads or opens an existing PDF document through Open method of PdfLoadedDocument class.
await loadedDocument.OpenAsync(file);
//Load the page.
PdfLoadedPage loadedPage = loadedDocument.Pages[0] as PdfLoadedPage;
//Create a new rectangle.
RectangleF docLinkAnnotationBounds = new RectangleF(10, 40, 30, 30);

//Create a new document link annotation.
PdfDocumentLinkAnnotation documentLinkAnnotation = new PdfDocumentLinkAnnotation(docLinkAnnotationBounds);
//Set the annotation text.
documentLinkAnnotation.Text = "Document link annotation";
//Set the existing page for navigation.
PdfLoadedPage navigationPage = loadedDocument.Pages[1] as PdfLoadedPage;
//Set the pdf destination.
documentLinkAnnotation.Destination = new PdfDestination(navigationPage);
//Set the document link annotation location.
documentLinkAnnotation.Destination.Location = new System.Drawing.PointF(10, 0);
//Add this annotation to respective page.
loadedPage.Annotations.Add(documentLinkAnnotation);

//Save the PDF document to stream.
MemoryStream stream = new MemoryStream();
await loadedDocument.SaveAsync(stream);
//Close the document.
loadedDocument.Close(true);
//Save the stream as PDF document file in local machine. Refer to PDF/UWP section for respected code samples.
Save(stream, "DocumentLinkAnnotation.pdf");
//Load the PDF document.
FileStream docStream = new FileStream("fileName.pdf", FileMode.Open, FileAccess.Read);
PdfLoadedDocument loadedDocument = new PdfLoadedDocument(docStream);
//Load the page.
PdfLoadedPage loadedPage = loadedDocument.Pages[0] as PdfLoadedPage;
//Create a new rectangle.
RectangleF docLinkAnnotationBounds = new RectangleF(10, 40, 30, 30);

//Create a new document link annotation.
PdfDocumentLinkAnnotation documentLinkAnnotation = new PdfDocumentLinkAnnotation(docLinkAnnotationBounds);
//Set the annotation text.
documentLinkAnnotation.Text = "Document link annotation";
//Set the existing page for navigation.
PdfLoadedPage navigationPage = loadedDocument.Pages[1] as PdfLoadedPage;
//Set the pdf destination.
documentLinkAnnotation.Destination = new PdfDestination(navigationPage);
//Set the document link annotation location.
documentLinkAnnotation.Destination.Location = new PointF(10, 0);
//Add this annotation to respective page.
loadedPage.Annotations.Add(documentLinkAnnotation);

//Save the document into stream.
MemoryStream stream = new MemoryStream();
loadedDocument.Save(stream);
//Set the position as '0'.
stream.Position = 0;
//Close the document.
loadedDocument.Close(true);
//Defining the ContentType for pdf file.
string contentType = "application/pdf";
//Define the file name.
string fileName = "DocumentLinkAnnotation.pdf";
//Creates a FileContentResult object by using the file contents, content type, and file name.
return File(stream, contentType, fileName);
//Load the file as stream.
Stream docStream = typeof(App).GetTypeInfo().Assembly.GetManifestResourceStream("Sample.Assets.Sample.pdf");
PdfLoadedDocument loadedDocument = new PdfLoadedDocument(docStream);
//Load the page.
PdfLoadedPage loadedPage = loadedDocument.Pages[0] as PdfLoadedPage;
//Create a new rectangle.
RectangleF docLinkAnnotationBounds = new RectangleF(10, 40, 30, 30);

//Create a new document link annotation.
PdfDocumentLinkAnnotation documentLinkAnnotation = new PdfDocumentLinkAnnotation(docLinkAnnotationBounds);
//Set the annotation text.
documentLinkAnnotation.Text = "Document link annotation";
//Set the existing page for navigation.
PdfLoadedPage navigationPage = loadedDocument.Pages[1] as PdfLoadedPage;
//Set the pdf destination.
documentLinkAnnotation.Destination = new PdfDestination(navigationPage);
//Set the document link annotation location.
documentLinkAnnotation.Destination.Location = new Syncfusion.Drawing.PointF(10, 0);
//Add this annotation to respective page.
loadedPage.Annotations.Add(documentLinkAnnotation);

//Save the PDF document to stream.
MemoryStream stream = new MemoryStream();
loadedDocument.Save(stream);
//Close the document.
loadedDocument.Close(true);
//Save the stream into pdf file.
//The operation in Save under Xamarin varies between Windows Phone, Android and iOS platforms. Please refer PDF/Xamarin section for respective code samples.
if (Device.OS == TargetPlatform.WinPhone || Device.OS == TargetPlatform.Windows)
{
    Xamarin.Forms.DependencyService.Get<ISaveWindowsPhone>().Save("DocumentLinkAnnotation.pdf", "application/pdf", stream);
}
else
{
    Xamarin.Forms.DependencyService.Get<ISave>().Save("DocumentLinkAnnotation.pdf", "application/pdf", stream);
}

You can download a complete working sample from GitHub.

Working with external document navigation

You can open external documents like images, text files, PDF, etc. using PdfFileLinkAnnotation class.

Please refer the below code snippet for navigating to external documents.

//Create the PDF document.
PdfDocument document = new PdfDocument();
//Creates a new page. 
PdfPage page = document.Pages.Add();
//Create a new rectangle.
RectangleF bounds = new RectangleF(10, 40, 30, 30);

//Create a link for image file. 
PdfFileLinkAnnotation fileLinkAnnotation = new PdfFileLinkAnnotation(bounds, @"..\..\Data\logo.png");
//Add this annotation to a page.
page.Annotations.Add(fileLinkAnnotation);

//Save the document to disk.
document.Save("FileLinkAnnotation.pdf");
//close the document.
document.Close();
'Create the PDF document
Dim document As New PdfDocument()
'Creates a new page and adds it as the last page of the document
Dim page As PdfPage = document.Pages.Add()
'Create a new rectangle
Dim rectangle As New RectangleF(10, 40, 30, 30)

'Create a link for image file 
Dim fileLinkAnnotation As New PdfFileLinkAnnotation(rectangle, "..\..\Data\logo.png")
'Add this annotation to a page
page.Annotations.Add(fileLinkAnnotation)

'Save the document to disk
document.Save("FileLinkAnnotation.pdf")
'close the document
document.Close()
//PDF supports external document navigation only in Windows Forms, WPF, ASP.NET and ASP.NET MVC platforms.
//PDF supports external document navigation only in Windows Forms, WPF, ASP.NET and ASP.NET MVC platforms.
//PDF supports external document navigation only in Windows Forms, WPF, ASP.NET and ASP.NET MVC platforms.

You can download a complete working sample from GitHub.

NOTE

The above link makes use of the absolute path of the file for navigation. So, moving the files to another machine or location may lead to file not found error in PDF reader applications.

To open a file in relative path, the PdfLaunchAction can be used. While using the relative path in launch action, the files can be moved to any machine, provided the relative path is being maintained. The below code snippet explains the same.

//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Create a new page.
PdfPage page = document.Pages.Add();

//Create the button field.
PdfButtonField submitButton = new PdfButtonField(page, "submitButton");
submitButton.Bounds = new RectangleF(100, 160, 100, 20);
submitButton.Text = "Launch";
//Create a the PdfLaunchAction.
PdfLaunchAction launchAction = new PdfLaunchAction(@"..\..\Data\ Document.txt", PdfFilePathType.Relative);
//Set the launchAction to the submitButton.
submitButton.Actions.GotFocus = launchAction;
//Add the form field.
document.Form.Fields.Add(submitButton);

//Save the document to disk.
document.Save("output.pdf");
//close the document.
document.Close();
'Create a new PDF document
Dim document As New PdfDocument()
'Create a new page
Dim page As PdfPage = document.Pages.Add()

'Create a new PdfButtonField
Dim submitButton As New PdfButtonField(page, "submitButton")
submitButton.Bounds = New RectangleF(25, 160, 100, 20)
submitButton.Text = "Launch"
'Create a the PdfLaunchAction
Dim launchAction As New PdfLaunchAction("..\..\Data\Document.txt", PdfFilePathType.Relative)
'Set the launch Action to the submitButton
submitButton.Actions.GotFocus = launchAction
'Add the form field
document.Form.Fields.Add(submitButton)

'Save the document to disk
document.Save("output.pdf")
'close the document
document.Close()
//PDF supports external document navigation only in Windows Forms, WPF, ASP.NET and ASP.NET MVC platforms.
//PDF supports external document navigation only in Windows Forms, WPF, ASP.NET and ASP.NET MVC platforms.
//PDF supports external document navigation only in Windows Forms, WPF, ASP.NET and ASP.NET MVC platforms.

You can download a complete working sample from GitHub.