WPF binding xaml UI property to dynamic instance control property

Question

I have a custom media player object that I create in code behind from a user control. There can be 1 to 4 of these at any time, but i want to bind the volume and the mute property of only one to a xaml control EG.

The control is:

MediaControlplayer  vcMediaPlayerMaster = new MediaControlplayer();

In this case the mute option to the ischecked state of the control does not work. How can I hook the binding up to the properties of the control when it is instantiated in code behind ?

xaml is like this. The variable vcMediaPlayerMaster is a global variable in code behind. When i instantiated it i assumed its declaration as a global predefined variable would allow the xaml below to bind to it, but it seems not to be the case.

<ToggleButton x:Name="btnAudioToggle" ToolTip="Audio Mute/Unmute"  
Click="BtnAudioToggle_OnClick" IsChecked="{Binding Mode =TwoWay, 
ElementName=vcMediaPlayerMaster, Path=Mute}" BorderBrush="LightBlue" 
Width="32" Height="32" Margin="0,5,10,10" Background="{StaticResource 
IbAudio}" Style="{DynamicResource ToggleButtonStyle1}" > </ToggleButton>

I thought perhaps creating a binding in code behind may be the way to go, but i cant seem to find a simple example that explains the code behind process to do that to fit my case.

Answer 1

You could create a helper class to hold the currently active MediaPlayer.
As a simple example:

public class MediaPlayerHelper : INotifyPropertyChanged
{
    private MediaControlplayer currentPlayer;

    public static MediaPlayerHelper Instance { get; } = new MediaPlayerHelper();

    public MediaControlplayer CurrentPlayer 
    { 
        get => this.currentPlayer;
        set { /* Implement a setter with INotifyPropertyChanged */ }
    }

    // Implement INotifyPropertyChanged here
}

The binding to this would look like the following

<Slider Value="{Binding Volume, Source={x:Static helper:MediaPlayerHelper.Instance}}"/>

Don't forget to include the namespace in the opening tag of your class in XAML:

xmlns:helper="clr-namespace:SomeNamespace.Helper"

Now you just have to change the currently used MediaPlayer whenever it changes:

MediaPlayerHelper.Instance.CurrentPlayer = newCurrentPlayer;

Answer 2

Ok i finally got it to work. Applied the binding in code behind fully. I was able to bind the property i wanted to the ischecked property of a button to toggle the bool property of the mediaplayer object

 MediaControlplayer  vcMediaPlayerMaster = new MediaControlplayer();
 Binding myMuteBinding = new Binding("Mute");
 myMuteBinding.Source = vcMediaPlayerMaster;
 myMuteBinding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;
 myMuteBinding.Mode = BindingMode.TwoWay;
 btnAudioToggle.SetBinding(SimpleButton.IsCheckedProperty, myMuteBinding);

So this worked fine for me and i used the same principle to bind other properties.