How to update Source property of MediaElement and start playback in Silverlight 3.0

Question

I'm writing a small Silverlight media player application. In the top of the page i have an horizontal listbox with listboxitems. The listbox is bound to a datasource containg an object I've created called ContentItem. The ContentItem is defined like this:

public class ContentItem
    {
        public string CoverUrl { get; set; }
        public string ResourceUrl { get; set; }

        public ContentItem()
        {
        }

    }

I also have an Media element:

<MediaElement x:Name="MediaBox" Source="http://localhost/repository/FighterPilot.wmv" Stretch="Fill"/>

So my thaught was, when the user chooses a new ContentItem from the listbox, I want to change the source of the MediaElement and start playing the new ContentItem. To do this, I've used the ListBox SelectionChange event: private void CoverFlowList_SelectionChanged(object sender,

System.Windows.Controls.SelectionChangedEventArgs e)
        {
            MediaBox.Stop();
            ListBoxItem SelectedItem = (ListBoxItem)sender;
            ContentItem SelectedContent = (ContentItem)SelectedItem.Content;
            MediaBox.Source = new Uri(SelectedContent.ResourceUrl);
            MediaBox.Play();
        }

But this does not want to work. When I debug the code, I can step all the way to ListBoxItem SelectedItem = (ListBoxItem)sender; but at this line it all freezes. The webbrowser shows a blank page, and the debugger (Visual Studio 2008) seems is still debugging but nothing happens.

Any idea what I'm doing wrong here? Any tips on how I could implement this functionality different?

I'm very thankful for advice!

Answer 1

The error was in my typecasting. Changing

ListBoxItem SelectedItem = (ListBoxItem)sender;
ContentItem SelectedContent = (ContentItem)SelectedItem.Content;

into

ContentItem SelectedItem = (ContentItem)((ListBox)sender).SelectedItem;

Solved it. So the obvious error was that the ListBoxItem was not the sender since the ListBox ofcourse was the sender.

Thanks to everyone who wasted valuable time trying to correct my sloppy written code.

Answer 2

What I did: Uri SomeVariable = new Uri("Devil May Cry - Shall Never Surrender", UriKind.RelativeOrAvsolute); MyPlayer.Source = SomeVariable;