Showing a File
This help article discusses different ways of loading a document in RadPdfViewer and their customization options.
Showing a PDF file
RadPdfViewer exposes a DocumentSource property of type FixedDocumentStreamSource that can be used to pass a PDF file to the control. There are several ways to set the property.
Setting the DocumentSource in XAML
First, you need to declare the Telerik namespace as shown in Example 1.
Example 1: Define Telerik namespace
xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
After that, you can proceed to add the PdfViewer control to the user control as shown in Example 2.
Make sure to set the Build Action of the file to Resource so it can be accessed through URI.
Example 2: Create RadPdfViewer
<Grid>
<telerik:RadPdfViewer x:Name="pdfViewer" DocumentSource="PdfViewerDemo;component/SampleData/Sample.pdf"/>
</Grid>
In Example 2, a file named "Sample.pdf" embedded in a "Sample Data" folder in the WPF project will be shown when the page is loaded. PdfViewerDemo is the name of the project.
PDF files can be opened as long as you can obtain a stream with their content that supports Read and Seek operations. If the stream supports only Read, its content should be copied to a MemoryStream, which will enable the Seek operation as well and will facilitate RadPdfViewer to show the document. Notice that the document is loaded asynchronously and the stream shouldn't be closed.
Setting DocumentSource in Code-Behind
In code-behind, you can set the DocumentSource to either a URI or a stream.
Example 3 shows how a PDF file can be loaded from a file embedded as a resource through a stream:
Example 3: Load PDF from a stream
private void LoadFromStream(object sender, System.Windows.RoutedEventArgs e)
{
Stream str = App.GetResourceStream(new System.Uri("PdfViewerDemo;component/SampleData/Sample.pdf", System.UriKind.Relative)).Stream;
this.pdfViewer.DocumentSource = new PdfDocumentSource(str);
}
Example 4 shows how a PDF can be loaded from a file embedded as a resource by passing its URI:
Example 4: Load PDF from a URI
private void LoadFromUri(object sender, System.Windows.RoutedEventArgs e)
{
this.pdfViewer.DocumentSource = new PdfDocumentSource(new System.Uri("PdfViewerDemo;component/SampleData/Sample.pdf", System.UriKind.Relative));
}
In Example 3 and Example 4, PdfViewerDemo is the name of the project and the PDF file is embedded as a resource in a folder called SampleData.
The PdfDocumentSource class exposes the Loaded event. This event is not related to the parsing of the content but is fired just after the document is being imported.
Setting the Document in Code-Behind
PdfDocumentSource internally uses the PdfFormatProvider class to create a document for RadPdfViewer. This allows you to easily import your documents directly using PdfFormatProvider instead of PdfDocumentSource.
Example 5: Set RadFixedDocument through PdfFormatProvider
string pdfFilePath = "Sample.pdf";
MemoryStream stream = new MemoryStream();
using (Stream input = File.OpenRead(pdfFilePath))
{
input.CopyTo(stream);
}
PdfFormatProvider provider = new PdfFormatProvider();
provider.ImportSettings = PdfImportSettings.ReadOnDemand;
RadFixedDocument doc = provider.Import(stream);
this.pdfViewer.Document = doc;
Binding the DocumentSource of RadPdfViewer
The DocumentSource of RadPdfViewer is implemented as a dependency property and can be bound to a URI, string representing a URI, or a stream. This is done with the help of PdfDocumentSourceValueConverter, which caters to creating a PdfDocumentSource and presenting it to the viewer.
Example 6 and Example 7 show how to declare the converter:
Example 6: Define a Fixed namespace
xmlns:fixed="clr-namespace:Telerik.Windows.Documents.Fixed;assembly=Telerik.Windows.Controls.FixedDocumentViewers"
Example 7: Define a PdfDocumentSourceValueConverter
<Grid.Resources>
<fixed:PdfDocumentSourceValueConverter x:Key="PdfDocumentSourceValueConverter" />
</Grid.Resources>
The bound property can be implemented as shown in Example 8 and Example 9.:
Example 8: Create the property
public class Context
{
public [string/Uri/Stream] Source { get; set; }
}
Example 9: Bind the DocumentSource property of RadPdfViewer
<telerik:RadPdfViewer x:Name="viewer" DocumentSource="{Binding Source, Converter={StaticResource PdfDocumentSourceValueConverter}}" />
Specifying Reading Mode
You can control the way the documents are loaded in RadPdfViewer. You can choose between loading the whole document at one time or loading it page by page. The second option means that you no longer needed to parse the entire document in order to show it. However, you will need to keep the stream to the document file open.
You can control how the document is loaded by setting the PdfViewer.DefaultImportSettings property. This property is used when the OpenPdfDocumentCommand is triggered to open a PDF file and could be set to one of the settings exposed by the PdfImportSettings class.
Example 10: Setting DefaultImportSettings
this.pdfViewer.DefaultImportSettings = PdfImportSettings.ReadOnDemand;
Another option to set the reading mode is through the constructors that accept PdfImportSettings when creating a new instance of the PdfDocumentSource class.
The default settings used by PdfViewer are ReadingMode: OnDemand and CopyStream: true to allow you parse only the needed content while you are not obligated to keep the stream to the document open.
If you want to change this behavior to read all the document pages at the beginning of the import, you can create a new PdfDocumentSource instance with FormatProviderSettings.ReadAllAtOnce predefined settings.
Example 11: Setting PdfImportSettings
PdfDocumentSource source = new PdfDocumentSource(stream/uri, PdfImportSettings.ReadOnDemand);
When you bind the DocumentSource property of RadPdfViewer and want to control the way bound documents are loaded, you can pass the desired settings as a ConverterParameter.
Example 12: Applying settings in binding scenario
<telerik:RadPdfViewer x:Name="viewer" DocumentSource="{Binding Uri, Converter={StaticResource PdfDocumentSourceValueConverter}, ConverterParameter=ReadOnDemand}" />
ReadAllAtOnce and ReadOnDemand are the valid values you can specify.
Handling Errors
Sometimes, the loading of the document might not success due to different reasons and an exception might be thrown. You can handle the errors in a way suitable for your application using the Exception Handling mechanism of the model of PdfViewer - PdfProcessing.