You can create links in PDF pages to external files using the PdfDocumentCreateFileLink(PdfPage, RectangleF, String) method. The file path can be given by a full or a relative path to the PDF document location.
In this demo you can learn how to attach external files and streams to a PDF document. When you create the attachment you can also give a page and a location in page where to create a link to the attachment marked with an icon.
The demo also creates a link to an external file from disk. The file path is relative to the PDF document location. When the link is clicked the file will be opened in an external viewer.
private void buttonCreatePdf_Click()
{
// create a PDF document
PdfDocument document = new PdfDocument();
// display the attachments when the document is opened
document.Viewer.PageMode = PdfPageMode.Attachments;
// create a page in document
PdfPage page1 = document.AddPage();
// create the true type fonts that can be used in document
Font sysFont = new Font("Times New Roman", 10, System.Drawing.GraphicsUnit.Point);
PdfFont pdfFont = document.CreateFont(sysFont);
PdfFont pdfFontEmbed = document.CreateFont(sysFont, true);
// create a reference Graphics used for measuring
Bitmap refBmp = new Bitmap(1, 1);
Graphics refGraphics = Graphics.FromImage(refBmp);
refGraphics.PageUnit = GraphicsUnit.Point;
// create an attachment with icon from file
string filePath1 = Application.StartupPath + @"\DemoFiles\Attach\TextAttach1.txt";
PdfAttachment pdfAttachment1 = document.CreateAttachmentFromFile(page1, new RectangleF(10, 30, 10, 20),
PdfAttachIconType.PushPin, filePath1);
pdfAttachment1.Description = "Attachment with icon from a file";
// write a description at the right of the icon
PdfText pdfAttachment1Descr = new PdfText(40, 35, pdfAttachment1.Description, pdfFontEmbed);
page1.Layout(pdfAttachment1Descr);
// create an attachment with icon from a stream
// The stream must remain opened until the document is saved
FileStream fileStream2 = new FileStream(filePath1, FileMode.Open, FileAccess.Read);
PdfAttachment pdfAttachment2 = document.CreateAttachmentFromStream(page1, new RectangleF(10, 60, 10, 20), PdfAttachIconType.Paperclip,
fileStream2, "AttachFromStream_WithIcon.txt");
pdfAttachment2.Description = "Attachment with icon from a stream";
// write a description at the right of the icon
PdfText pdfAttachment2Descr = new PdfText(40, 65, pdfAttachment2.Description, pdfFontEmbed);
page1.Layout(pdfAttachment2Descr);
// create an attachment without icon in PDF from a file
string filePath2 = Application.StartupPath + @"\DemoFiles\Attach\TextAttach2.txt";
document.CreateAttachmentFromFile(filePath2);
// create an attachment without icon in PDF from a stream
// The stream must remain opened until the document is saved
FileStream fileStream1 = new FileStream(filePath2, FileMode.Open, FileAccess.Read);
document.CreateAttachmentFromStream(fileStream1, "AttachFromStream_NoIcon.txt");
// create the external file link
string extFilePath = @"DemoFiles\Attach\TextAttach1.txt";
string linkText = String.Format("Click this link to open the '{0}' file from file system", extFilePath);
PdfText clickHereText = new PdfText(10, 100, linkText, pdfFontEmbed);
clickHereText.ForeColor = Color.Navy;
page1.Layout(clickHereText);
SizeF textSize = refGraphics.MeasureString(linkText, sysFont);
document.CreateFileLink(page1, new RectangleF(10,100,textSize.Width, textSize.Height), extFilePath);
// dispose the graphics used for measuring
refGraphics.Dispose();
refBmp.Dispose();
string pdfFile = Application.StartupPath + @"\DemoOutput\PdfAttachments.pdf";
try
{
document.WriteToFile(pdfFile);
}
catch (Exception ex)
{
return;
}
finally
{
document.Close();
fileStream1.Close();
}
}