/// <summary>
/// Observes a property that implements INotifyPropertyChanged, and automatically calls DelegateCommandBase.RaiseCanExecuteChanged on property changed notifications.
/// </summary>
/// <typeparam name="T">The object type containing the property specified in the expression.</typeparam>
/// <param name="propertyExpression">The property expression. Example: ObservesProperty(() => PropertyName).</param>
/// <returns>The current instance of DelegateCommand</returns>
protected internal void ObservesPropertyInternal <T>(Expression <Func <T> > propertyExpression)
{
AddPropertyToObserve(PropertySupport.ExtractPropertyName(propertyExpression));
HookInpc(propertyExpression.Body as MemberExpression);
}
/// <summary>
/// Observes a property that is used to determine if this command can execute, and if it implements INotifyPropertyChanged it will automatically call DelegateCommandBase.RaiseCanExecuteChanged on property changed notifications.
/// </summary>
/// <param name="canExecuteExpression">The property expression. Example: ObservesCanExecute((o) => PropertyName).</param>
/// <returns>The current instance of DelegateCommand</returns>
protected internal void ObservesCanExecuteInternal(Expression <Func <object, bool> > canExecuteExpression)
{
_canExecuteMethod = canExecuteExpression.Compile();
AddPropertyToObserve(PropertySupport.ExtractPropertyNameFromLambda(canExecuteExpression));
HookInpc(canExecuteExpression.Body as MemberExpression);
}
/// <summary>
/// Raises this object's PropertyChanged event.
/// </summary>
/// <typeparam name="T">The type of the property that has a new value</typeparam>
/// <param name="propertyExpression">A Lambda expression representing the property that has a new value.</param>
protected virtual void OnPropertyChanged <T>(Expression <Func <T> > propertyExpression)
{
var propertyName = PropertySupport.ExtractPropertyName(propertyExpression);
OnPropertyChanged(propertyName);
}