/// <summary>
/// Remove an existing observer for this dependency property. <b>This call is needed to avoid memory leaks!</b>
/// </summary>
/// <param name="dp"></param>
/// <param name="depObj">Dependency Object that observe this property</param>
/// <param name="callback">Callback method is called in case of property value change</param>
/// <returns>TRUE if success</returns>
public static bool RemoveValueChanged(this DependencyProperty dp, DependencyObject depObj, EventHandler callback)
{
var dependencyPropertyDescriptor = DependencyPropertyDescriptor.FromProperty(dp, depObj.GetType());
dependencyPropertyDescriptor.RemoveValueChanged(depObj, callback);
DependencyPropertyUtils.RaiseRemovePropertyObserver(dp, depObj);
return(true);
}
/// <summary>
/// Add an observer for this dependency property. <b>Please remove callback with <see cref="RemoveValueChanged"/> to avoid memory leaks!</b>
/// </summary>
/// <param name="dp"></param>
/// <param name="depObj">Dependency Object that observe this property</param>
/// <param name="callback">Callback method is called in case of property value change</param>
/// <param name="runImmediately">TRUE to run immediately (with this method call), otherwise FALSE. Default is TRUE</param>
/// <returns>TRUE if success</returns>
public static void AddValueChanged(this DependencyProperty dp, DependencyObject depObj, EventHandler callback, bool runImmediately = true)
{
var dependencyPropertyDescriptor = DependencyPropertyDescriptor.FromProperty(dp, depObj.GetType());
dependencyPropertyDescriptor.AddValueChanged(depObj, callback);
DependencyPropertyUtils.RaiseAddPropertyObserver(dp, depObj);
if (runImmediately)
{
callback(dp, new EventArgs());
}
}
