Aynchronous Loading

For better performance you can have the C1PdfViewer control load documents in the background asynchronously. Using the .NET await keyword, you can easily call asynchronous methods. To open a file selected by the user asynchronously, complete the following code:

Visual Basic
C#

Visual Basic	Copy Code
Dim openPicker As New FileOpenPicker() openPicker.FileTypeFilter.Add(".pdf") Dim file As StorageFile = Await openPicker.PickSingleFileAsync() If file IsNot Nothing Then Dim stream As Stream = Await file.OpenStreamForReadAsync() Await pdfViewer.LoadDocumentAsync(stream) End If

Visual Basic

Copy Code

Dim openPicker As New FileOpenPicker()

openPicker.FileTypeFilter.Add(".pdf")

Dim file As StorageFile = Await openPicker.PickSingleFileAsync()

If file IsNot Nothing Then
      
       Dim stream As Stream = Await file.OpenStreamForReadAsync()
      
       Await pdfViewer.LoadDocumentAsync(stream)
End If

C#	Copy Code
FileOpenPicker openPicker = new FileOpenPicker(); openPicker.FileTypeFilter.Add(".pdf"); StorageFile file = await openPicker.PickSingleFileAsync(); if (file != null) { Stream stream = await file.OpenStreamForReadAsync(); await pdfViewer.LoadDocumentAsync(stream); }

Copy Code

FileOpenPicker openPicker = new FileOpenPicker();

openPicker.FileTypeFilter.Add(".pdf");

StorageFile file = await openPicker.PickSingleFileAsync();

if (file != null)

{

    Stream stream = await file.OpenStreamForReadAsync();

    await pdfViewer.LoadDocumentAsync(stream);

}

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