Programmatic MediaElement plays Audio but no visual

Question

I've created a mediaelement using the following code:

var vFolder = await Windows.Storage.KnownFolders.VideosLibrary.GetFolderAsync(myFolder);
MediaElement AV1 = new MediaElement();

var file1 = await vFolder.GetFileAsync("movie (1).mp4");
var stream1 = await file1.OpenAsync(Windows.Storage.FileAccessMode.Read);

AV1.SetSource(stream1, file1.ContentType);
AV1.Height = 400;
AV1.Width = 300;
AV1.Visibility = Windows.UI.Xaml.Visibility.Visible;
//chainPanel.Children.Add(AV1);
AV1.Play();

When I run the code I can hear the movie play but I'm not seeing any vision. I've also tried using Margin with no luck. Eventually I want to programmatically add the mediaelement to the stack panel. Any ideas?

thanks.

Answer 1

What is chainPanel and why is it commented out? The MediaElement needs to be in the visual tree. You need to add it to a visible container such as your StackPanel before it will be displayed.

--Rob

Answer 2

Thanks that makes sense. chainPanel is the stackPanel but if I run the code it throws the error "Object reference not set to an instance of an object.". However if I create a new button and run "chainPanel.Children.Add(newbutton)" that works and I see the button show up. Am I missing a step with the media element somewhere?

Answer 3

Solved. The mediaelement needs to be added to the visual tree BEFORE setting the source, like this:

var vFolder = await Windows.Storage.KnownFolders.VideosLibrary.GetFolderAsync(myFolder);
MediaElement AV1 = new MediaElement();

var file1 = await vFolder.GetFileAsync("movie (1).mp4");
var stream1 = await file1.OpenAsync(Windows.Storage.FileAccessMode.Read);
chainPanel.Children.Add(AV1);
AV1.SetSource(stream1, file1.ContentType);