Loading password protected PDFs in Xamarin Pdf Viewer (SfPdfViewer)

5 Dec 20222 minutes to read

Password protected PDFs can be loaded using the LoadDocument(Stream pdfStream, string password) method.

string password = "PASSWORD";
pdfViewerControl.LoadDocument(pdfStream, password);

In the above code snippet, pdfStream is the Stream instance read from the encrypted PDF and password is the key with which the PDF is encrypted.

Loading password-protected PDF asynchronously

Xamarin PDF Viewer allows you to load the PDF document from the specified stream with password asynchronously using the LoadDocumentAsync method. You can also cancel the asynchronous PDF loading when it is in progress.

pdfViewerControl.LoadDocumentAsync(documentStream, password, cancellationTokenSource);

In the above code sample, documentStream is the Stream instance read from the encrypted PDF, and the password is the key with that the PDF is encrypted, and the cancellationTokenSource enables you to cancel the asynchronous PDF loading.

For canceling the asynchronous PDF loading and detecting the cancellation when it occurred, refer the Loading a PDF asynchronously section of Getting Started.

Handling invalid passwords

If the password provided with the LoadDocument(Stream pdfStream, string password) is invalid, then the PasswordErrorOccurred event is raised. The Title property of the PasswordErrorOccurredEventArgs parameter helps identify whether the event raised due to invalid password. In that case the Title property will read “Error loading encrypted PDF document”.

pdfViewerControl.PasswordErrorOccurred += PdfViewerControl_PasswordErrorOccurred;
private void PdfViewerControl_PasswordErrorOccurred(object sender, PasswordErrorOccurredEventArgs args)
{
    //Get the details regarding the password error occurred. 
    string title = args.Title;
    string description = args.Description;
}

NOTE

The event will also be raised when an encrypted PDF is loaded without providing a password using the LoadDocument(Stream pdfStream) overload.

Enable or disable the password protected view

The PDF viewer has a built-in view for entering the password of encrypted PDF document before display.

Password UI View

Password View

The users can enable or disable the password UI view based on their requirement. The password UI view can be disabled by setting the IsPasswordViewEnabled API to false. The default value of this API is true. The code snippet for disabling the view is as follows,

  • C#
    • //Disable the display of password UI view
pdfViewer.IsPasswordViewEnabled = false;

    Detecting the cancel operation of password view

    The event PasswordViewCancelButtonClicked will be raised when the user cancels the password entering process.

  • C#
    • pdfViewer.PasswordViewCancelButtonClicked += PdfViewer_PasswordViewCancelButtonClicked;

    NOTE

    You can also explore our Xamarin.Forms PDF Viewer example to knows the functionalities of each feature.