Question

I have a WPF Application using MVVM pattern. I have a Window in my project and use a CustomControl in my Window.
I need two commands in my Window for Start and Stop in my CustomControl . So I use a bool DependencyProperty like this :

public static readonly DependencyProperty IsStartModeProperty = DependencyProperty.Register(
    "IsStartMode", typeof(bool), typeof(RadarView), new FrameworkPropertyMetadata(false, OnCurrentReadingChanged));

public bool IsStartMode {
    get { return (bool)GetValue(IsStartModeProperty); }
    set { SetValue(IsStartModeProperty, value); }
}

Also following method is use for callback delegate in my dependency property:

public static void OnCurrentReadingChanged(DependencyObject doj, DependencyPropertyChangedEventArgs dp) {
    if (IsStartMode)
        Start();
    else
        Stop();
}

My problem is in use from IsStartMode property in up method, because this is not static. It has a build error.

Is Correct my solution? if is correct what I do?

Answer 1

You need to cast the first method argument to your Dependency Object class:

public static void OnCurrentReadingChanged(DependencyObject doj, DependencyPropertyChangedEventArgs dp) 
{ 
    var myObject = (RadarView)doj;

    if (myObject.IsStartMode) 
        myObject.Start(); 
    else 
        myObject.Stop(); 
} 

(As a side note, I would call the property IsRunning.)