Conditional in XAML file?

Question

I have the following XAML file:

<MediaElement Name="mediaElementOne"
              LoadedBehavior="Manual"
              Stretch="UniformToFill"
              ScrubbingEnabled="True"
              MediaOpened="Media_Success"
              MediaFailed="Media_Failure"/>

The MediaOpened property currently calls the "Media_Success" when the media loaded successfully.

My issue is with MediaFailed, because I only want MediaFailed to fire on a boolean, meaning I need this to be conditional based on a boolean in my .cs file for the aforementioned XAML file.

How do I write a conditional in a XAML file? Or how would I be able to do this on the .cs file.

Right now as soon as .net believes the media failed it fires the Media_Failure function. I don't want it to fire the Media_Failure function when a specific boolean is set to false and for reasons far outside the scope of this question I can't handle the condition inside of the Media_Failure function.

Additional info: Here is the method it fires on the .cs file:

private void Media_Failure(object sender, ExceptionRoutedEventArgs e){...}

Answer 1

A pattern like this comes to mind where you set or clear the MediaFailed event handler based on the boolean, which you make a property with a getter/setter.

private bool _isMediaFailureEnabled;
public bool isMediaFailureEnabled
{
    get
    {
        return _isMediaFailureEnabled;
    }

    set
    {
        if (_isMediaFailureEnabled != value)
        {
            _isMediaFailureEnabled = value;
            if (_isMediaFailureEnabled)
            {
                mediaElementOne.MediaFailed += MediaElementOne_MediaFailed;
            }
            else
            {
                mediaElementOne.MediaFailed -= MediaElementOne_MediaFailed;
                // OR
                // mediaElementOne.MediaFailed = null;
            }
        }
    }
}

You will have to inspire from this pattern and adapt to your code, but this should accomplish what you want.

Edit:

Thought about this more for some reason and arrived at an alternative which is very similar to what Maurice came up with, by using a level of abstraction to solve the problem.

Define a wrapper or the failed event:

MediaFailed="Media_Failure_Wrapper"

Always let this be called, and only call your original event handler when your boolean is true:

private void Media_Failure_Wrapper(object sender, ExceptionRoutedEventArgs e)
{
    if (_isMediaFailureEnabled)
    {
        return Media_Failure(sender, e);
    }
    else
    {
        e.Handled = true;
        return;
    }
}