DependencyProperty怎么样？

Question

我的问题是什么？它不起作用 （MVVM）

我得到空文本框，当我更改文本框文本时，不调用OnCurrentReadingChanged

namespace Test
{
  public partial class MainWindow : Window
  {
    public MainWindow()
    {
        DataContext = new BaseModel();      
        this.InitializeComponent();           
    }
    public static DependencyProperty ImgPositionProperty = DependencyProperty.Register("ImgPosition", typeof(string), typeof(MainWindow),
     new PropertyMetadata("ddd", new PropertyChangedCallback(OnCurrentReadingChanged)));

    private static void OnCurrentReadingChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        MessageBox.Show("1");
    }
  }
}

<Window xmlns:View="clr-namespace:Test">
  <Grid x:Name="LayoutRoot">
    <TextBox Margin="141,81,254,0" TextWrapping="Wrap" Text="{Binding View:MainWindow.ImgPosition, UpdateSourceTrigger=PropertyChanged}" VerticalAlignment="Top"/>
  </Grid>
</Window>

Answer 1

如果您绑定DependencyProperty上的MainWindow而非DataContext，则可以使用'FindAncestor'绑定

<TextBox Text="{Binding ImgPosition, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type View:MainWindow}}, UpdateSourceTrigger=PropertyChanged}" />