关于 c#:Dependency 之后使用该属性的属性？

Dependency Properties that use the property afterwards?

我正在尝试设置一个名为 Sprite 的对象的依赖属性，一个 sprite 包含一个 spriteSheet 字符串，所以我希望能够传递一个 Sprite，然后该数据用于显示一个图像在我的控制中。

这是我目前的尝试

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public Sprite Sprite
{
get { return (Quiz.Sprite)GetValue(SpriteProperty); }
set {
spriteBrush.ImageSource = new BitmapImage(new Uri("/Project;component/" + value.spriteSheet, UriKind.RelativeOrAbsolute));

spriteTransform.TranslateX = -558;
spriteTransform.TranslateY = 0;

SetValue(SpriteProperty, value);
}
}

public static DependencyProperty SpriteProperty = DependencyProperty.Register(
"Sprite", typeof(Sprite), typeof(spriteView), new PropertyMetadata(new Quiz.Sprite() { spriteSheet ="wp7_buttons.png" }));
}

我如何让 set 方法的那部分运行，正如我在依赖属性文档中读到的那样，绑定时可能会直接调用 SetValue 和 GetValue。

添加一个 DependencyPropertyChangedEventHandler 并将代码从您的设置器移到那里：

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public Sprite Sprite
{
get { return (Quiz.Sprite)GetValue(SpriteProperty); }
set { SetValue(SpriteProperty, value); }
}

public static DependencyProperty SpriteProperty = DependencyProperty.Register(
"Sprite", typeof(Sprite), typeof(SpriteView), new PropertyMetadata(new Quiz.Sprite() { spriteSheet ="wp7_buttons.png" },
SpriteChanged));

private static void SpriteChanged(object sender, DependencyPropertyChangedEventArgs e)
{
SpriteView view = sender as SpriteView;
Sprite sprite = e.NewValue as Sprite;
if (view != null && sprite != null)
{
view.spriteBrush.ImageSource = new BitmapImage(new Uri("/Project;component/" + sprite.spriteSheet, UriKind.RelativeOrAbsolute));
view.spriteTransform.TranslateX = -558;
view.spriteTransform.TranslateY = 0;
}
}

没错，你不能用 SetValue 来引入任何逻辑。相反，您应该使用 PropertyValueChanged 处理程序。类似于：

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public Sprite Sprite
{
get { return (Quiz.Sprite)GetValue(SpriteProperty); }
set { SetValue(SpriteProperty, value); }
}

private static void OnSpritPropertyValueChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
var control = d as YourControl;
var sprite = e.NewValue as Quiz.Sprite;

control.spriteBrush.ImageSource = new BitmapImage(new Uri("/Project;component/" + sprite.spriteSheet, UriKind.RelativeOrAbsolute));

control.spriteTransform.TranslateX = -558;
control.spriteTransform.TranslateY = 0;
}

public static DependencyProperty SpriteProperty = DependencyProperty.Register(
"Sprite", typeof(Sprite), typeof(spriteView),
new PropertyMetadata(new Quiz.Sprite() { spriteSheet ="wp7_buttons.png" }, OnSpritPropertyValueChanged));