自定义控件上的WPF PropertyPath

Question

我有一个问题，我创建了一个名为Tile的控件(就像Windows10上的Tile )。此磁贴通过使用投影类模拟3D旋转，就像Silverlight中的投影类一样。

我们有一个基本投影类，如下所示：

abstract public class Projection
    : FrameworkElement
{
    static public readonly DependencyProperty RotationZProperty = DependencyProperty.Register(
          nameof(RotationZ),
          typeof(double),
          typeof(Projection),
          new UIPropertyMetadata(0.0, OnRotationChanged));

    static public readonly DependencyProperty RotationYProperty = DependencyProperty.Register(
            nameof(RotationY),
            typeof(double),
            typeof(Projection),
            new UIPropertyMetadata(0.0, OnRotationChanged));

    static public readonly DependencyProperty RotationXProperty = DependencyProperty.Register(
            nameof(RotationX),
            typeof(double),
            typeof(Projection),
            new UIPropertyMetadata(0.0, OnRotationChanged));

public double RotationZ
{
    get { return this.GetValue<double>(RotationZProperty); }
    set { SetValue(RotationZProperty, value); }
}

public double RotationY
{
    get { return this.GetValue<double>(RotationYProperty); }
    set { SetValue(RotationYProperty, value); }
}

public double RotationX
{
    get { return this.GetValue<double>(RotationXProperty); }
    set { SetValue(RotationXProperty, value); }
}

public FrameworkElement Child
{
    get;
    set;
}

static private void OnRotationChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if (d is Projection pl)
            {
                pl.OnRotationChanged();
            }
        }

        private void OnRotationChanged()
        {
            // Some code
        }}

After that, we have the PlaneProjectionClass :

     [ContentProperty("Child")]
    sealed public class PlaneProjection
        : Projection
    {   
    }

Tile类使用Projection类型依赖属性：

     public class Tile
    {
     static public readonly DependencyProperty PlaneProjectionProperty = DependencyProperty.Register(
            nameof(Projection),
            typeof(Projection),
            typeof(Tile),
            new UIPropertyMetadata());

 public Projection Projection
        {
            get { return (Projection)GetValue(PlaneProjectionProperty); }
            private set { SetValue(PlaneProjectionProperty, value); }
        }

        override public void OnApplyTemplate()
        {
            Projection = GetTemplateChild("PART_Projection") as Projection;
        }
     }

因此，对于XAML，我们在ControlTemplate中有如下代码：

    <controls:PlaneProjection x:Name="PART_PlaneProjection">
    <Border>
    <Grid>
      <!-- Some design -->
    </Grid>
    </Border>
</controls:PlaneProjection>

现在我想要对平面投影进行动画处理。

因此，我创建了故事板，并使用rotationX对投影进行动画处理：

static public void CreateAnimation(Tile tile)
{
    Storyboard.SetTarget(anim, tile);
    Storyboard.SetTargetProperty(doubleAnim, new PropertyPath("(Tile.Projection).(PlaneProjection.RotationX"));
 }

但是在调试时，我遇到这样的错误:无法解析属性'(Tile.Projection).(PlaneProjection.RotationX)路径上的所有属性引用

我不明白这个错误:(关于在自定义控件上使用PropertyPath有什么想法吗？

Answer 1

类Tile中的Projection属性不遵循依赖属性的命名约定。

例如，它应该看起来像这样：

public static readonly DependencyProperty PlaneProjectionProperty =
    DependencyProperty.Register(nameof(PlaneProjection), typeof(Projection), typeof(Tile));

public Projection PlaneProjection
{
    get { return (Projection)GetValue(PlaneProjectionProperty); }
    private set { SetValue(PlaneProjectionProperty, value); }
}

属性路径应该是这样的：

Storyboard.SetTargetProperty(anim, new PropertyPath("PlaneProjection.RotationX"));

你甚至不需要一个故事板。只要打个电话

tile.PlaneProjection.BeginAnimation(Projection.RotationXProperty, anim);

需要注意的是，私有setter不会使依赖属性成为只读的。详情请参见Read-Only Dependency Properties。