How to pass seleced file details to another page - UWP?

问题

I have a launcher page(MainPage1.xaml).There is a button to select video file from device. Now I want to play that selected file on next page (MainPage2.xaml). How can I get this selcted file StorageFile file on next page?

  private async void Button_Click(object sender, RoutedEventArgs e)
    {  
        StorageFile file;

        FileOpenPicker openPicker = new FileOpenPicker();
        foreach (string extension in FileExtensions.Video)
        {
            openPicker.FileTypeFilter.Add(extension);
        }
        file = await openPicker.PickSingleFileAsync();

        this.Frame.Navigate(typeof(MainPage2), file);
    }

回答1:

You have to override the OnNavigatedTo() method in your page (next Page) which is expecting the StorageFile:

protected override void OnNavigatedTo(NavigationEventArgs e)
{
     if (e.Parameter != null)
     {
        StorageFile file = (StorageFile)e.Parameter;
     }
}

Hope this helps..

回答2:

Override OnNavigatedTo in DestinationPage

protected override void OnNavigatedTo(NavigationEventArgs e)
{
  base.OnNavigatedTo(e);

  var parameters = e.Parameter;  // it will give your file reference
}

回答3:

There are two parts to this: as noted in other answers, the second argument to the Navigate method will be passed to OnNavigatedTo in the NavigationEventArgs.Parameter .

This is good for basic types, but isn't sufficient for a StorageFile. Quoting from the Frame.Navigate docs:

parameter Object The navigation parameter to pass to the target page; must have a basic type (string, char, numeric, or GUID) to support parameter serialization using GetNavigationState.

The StorageFile will work for a direct navigation, but since it isn't serializable it can get lost in the back stack, while suspending, etc.

Instead of passing the StorageFile directly stow it in a global dictionary and pass a string or GUID key that the OnNavigatedTo method can use to look up the StorageFile on the other side.

For the specific case of a StorageFile you can use the FutureAccessList. See Track recently used files and folders

来源：https://stackoverflow.com/questions/46639669/how-to-pass-seleced-file-details-to-another-page-uwp