Using FileOpenPicker with Silverlight

Question

Windows Phone 8.1 supports file open and file save pickers. I want to use a file open picker with a project which was converted form WP 8 to WP 8.1 (Silverlight).

I can open the FileOpenPicker as follows:

FileOpenPicker picker = new FileOpenPicker();
picker.FileTypeFilter.Add(".txt");
picker.PickSingleFileAndContinue(); 

Now, all examples I have found use the new universal Windows runtime where the resulting files are catched as follows in the App.xaml.cs:

protected override void OnActivated(IActivatedEventArgs e) {     
    ContinuationActivatedEventArgs = e as IContinuationActivatedEventArgs; 
    if (ContinuationEventArgsChanged != null) 
    { 
        // Handle file here
    } 
} 

The problem is that the converted Silverlight apps do not implement this method. Instead I derived the principle idea from another example for Silverlight apps (http://msdn.microsoft.com/en-us/library/dn655125%28v=vs.105%29.aspx):

private void Application_Activated(object sender, ActivatedEventArgs e)
{
    var eventArgs = e as IContinuationActivatedEventArgs;
    if (eventArgs != null)
    {
        // Handle file here
    }
}

But this does not work (e.g. eventArgs is always NULL).

There is another example here: http://msdn.microsoft.com/en-us/library/windowsphone/develop/dn642086%28v=vs.105%29.aspx. This uses the following method in the app.xaml.cs:

private void Application_ContractActivated(object sender, IActivatedEventArgs e)
{
        var filePickerContinuationArgs = e as FileOpenPickerContinuationEventArgs;
        if (filePickerContinuationArgs != null)
        {
        // Handle file here
        }
}

But this method is never called in my app.

Has someone a hint/idea how get the FileOpenPicker to work with a Silverlight WP8.1 app?

Regards,

Answer 1

It seems that one needs to manually add an event handler to Microsoft.Phone.Shell.PhoneApplicationService.Current.ContractActivated:

Microsoft.Phone.Shell.PhoneApplicationService.Current.ContractActivated +=  Application_ContractActivated;

private void Application_ContractActivated(object sender, IActivatedEventArgs e)
{
        var filePickerContinuationArgs = e as FileOpenPickerContinuationEventArgs;
        if (filePickerContinuationArgs != null)
        {
        // Handle file here
        }
}