DependencyPropertyChanged回調事件沒有被觸發

Question

我有一個UserControl名爲MultiChartControl，它有一個名爲MultiChartInputDetails的依賴項屬性。

public ChartsData MultiChartInputDetails 
    { 
     get { return (ChartsData)GetValue(MultiChartInputDetailsProperty); } 
     set { SetValue(MultiChartInputDetailsProperty, value); } 
    } 

    public static readonly DependencyProperty MultiChartInputDetailsProperty = 
     DependencyProperty.Register("MultiChartInputDetails", typeof(ChartsData), typeof(MultiChartControl), new UIPropertyMetadata(new PropertyChangedCallback(MultiChartInputDetailsChanged))); 

但接下來的回調方法不會被解僱甚至一度：

private static void MultiChartInputDetailsChanged(DependencyObject d, DependencyPropertyChangedEventArgs args) 
    { 
     MultiChartControl chart = d as MultiChartControl; 
     if (chart != null) 
     { 
      if (chart.ChartGrid.Children != null) 
       chart.ChartGrid.Children.Clear();     
      chart.InitilizeData(); 
     } 

     MessageBox.Show("MultiChartInputDetailsChanged fired"); 
    } 

和主主控：

<multicharting:MultiChartControl x:Uid="multicharting:MultiChartControl_1" 
              MultiChartInputDetails="{Binding Path=MultiChartsInputDetails, ElementName=Chart, Converter={StaticResource DebugConverter}}"/> 

Answer 1

這是因爲DependencyProperty的未設置通過綁定雙向。完成如下：

DependencyProperty.Register("MultiChartInputDetails", 
    typeof(ChartsData), 
    typeof(MultiChartControl), 
    new FrameworkPropertyMetadat(default(ChartsData), 
     FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, 
     MultiChartInputDetailsChanged) 

此外，檢查是否有任何綁定錯誤。如果你不想提供執行雙向每默認綁定，那麼你可以寫成如下您bindinga依賴屬性：

<multicharting:MultiChartControl x:Uid="multicharting:MultiChartControl_1" 
    MultiChartInputDetails="{Binding Path=MultiChartsInputDetails, 
            Mode=TwoWay, 
            ElementName=Chart, 
            Converter={StaticResource DebugConverter}}"/>