從ContentControl綁定前景

Question

我對WindowsPhone 8和ControlTemplate有綁定問題。 下面是一個例子：

<UserControl.Resources> 
<Style TargetType="Button"> 
    <Setter Property="Template"> 
     <Setter.Value> 
      <ControlTemplate TargetType="Button"> 
       <ContentControl x:Name="ContentContainer" Foreground="Red" Content="{TemplateBinding Content}"/> 
      </ControlTemplate> 
     </Setter.Value> 
    </Setter> 
</Style> 
</UserControl.Resources> 

<Button> 
    <Button.Content> 
     <TextBlock Text="123"/> 
    </Button.Content> 
<Button> 

我想在我的Button.Content前景「紅」我在ContentContainer定義爲使用。但沒有什麼作品... 目標是在我的風格的VisualState中更改ContentContainer前景。誰能幫我？

Answer 1

你應該這樣做：

<Button Content="123"/> 

而不是把TextBlock的。

不過，如果你想保持的TextBlock反正你應該做的：

<Style TargetType="TextBlock"> 
      <Setter Property="Foreground"> 
       <Setter.Value> 
        red 
       </Setter.Value> 
      </Setter> 
     </Style> 

Answer 2

管理與行爲拉這一關。這是一個相當複雜的解決方案， 但它是唯一一個我找到工作：

首先，一些的Util東西：

public static class IEnumerableExt 
{ 
    public static T FirstOrDefault<T>(this IEnumerable<T> source) 
    { 
     if (source.Count() > 0) 
      return source.ElementAt(0); 
     return default(T); 
    } 
} 

和...

public static class DependencyObjectExt 
{ 
     public static DependencyObject GetChild(this DependencyObject @this, int childIndex) 
     { 
      return VisualTreeHelper.GetChild(@this, childIndex); 
     } 

     public static IEnumerable<DependencyObject> GetChildren(this DependencyObject @this) 
     { 
      for(int i = 0; i < VisualTreeHelper.GetChildrenCount(@this); i++) 
      { 
       yield return @this.GetChild(i); 
      } 
     } 

     public static IEnumerable<T> FindChildrenOfType<T>(this DependencyObject @this) where T : DependencyObject 
     { 
      foreach(var child in @this.GetChildren()) 
      { 
       if(child is T) 
       { 
        yield return child as T; 
       } 
      } 
     } 

     public static IEnumerable<T> FindDescendantsOfType<T>(this DependencyObject @this) where T : DependencyObject 
     { 
      IEnumerable<T> result = Enumerable.Empty<T>(); 

      foreach(var child in @this.GetChildren()) 
      { 
       if(child is T) 
       { 
        result = result.Concat(child.ToEnumerable().Cast<T>()); 
       } 
       result = result.Concat(child.FindDescendantsOfType<T>()); 
      } 

      return result; 
     } 
} 

現在，讓我們定義一個行爲綁定：

public class ContentControlForegroundBindingBehavior : Behavior<Control> 
{ 
    public static DependencyProperty ParentProperty = 
     DependencyProperty.Register("Parent", typeof(Control), 
      typeof(ContentControlForegroundBindingBehavior), new PropertyMetadata(null)); 

    public Control Parent 
    { 
     get { return (Control)this.GetValue(ParentProperty); } 
     set { this.SetValue(ParentProperty, value); } 
    } 


    protected override void OnAttached() 
    { 
     base.OnAttached(); 

     AssociatedObject.Loaded += (sender, e) => 
     { 
      if (Parent == null) return; 

      var control = AssociatedObject as Control; 
      if (control == null) return; 


      var contentControl = Parent.FindDescendantsOfType<ContentControl>().FirstOrDefault(); 
      if (contentControl == null) return; 

      control.SetBinding(Control.ForegroundProperty, new Binding() 
      { 
       NotifyOnSourceUpdated = true, 
       Mode = BindingMode.OneWay, 
       UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged, 
       BindsDirectlyToSource = true, 
       Path = new PropertyPath(Control.ForegroundProperty), 
       Source = contentControl 
      }); 
     }; 
    } 
} 

此行爲的作用是綁定c控制的前景到指定父級的模板中找到的ContentControl的前景。 這是你如何使用它（在xaml中）：

xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity" 
     xmlns:behaviors=" ---------- Your Behaviors Namespace ---------" 

<Button x:Name="SomeName" 
       Width="125" 
       Height="30" 
       Click="OnButtonClick" 
       HorizontalAlignment="Left" 
       VerticalAlignment="Top" 
       Margin="50,54,0,0"> 
      <Button.Content> 
       <controls:IconText Icon="SomeIcon.png" 
            Text="SomeText"> 
        <i:Interaction.Behaviors> 
         <behaviors:ContentControlForegroundBindingBehavior Parent="{Binding ElementName=SomeName}"/> 
        </i:Interaction.Behaviors> 
       </controls:IconText> 
      </Button.Content> 
</Button>