如何使用Child-deined Attached Properties？

我把你的例子作为基础,删除了一点,并得到了这个例子.我删除它们以显示最小的工作示例.

首先,我删除了CellBorderThickness属性,因为已经附加了依赖属性.

Son

// Removed
public Thickness CellBorderThickness
{
    get { return (Thickness)GetValue(CellBorderThicknessProperty); }
    set { SetValue(CellBorderThicknessProperty, value); }
}

在我父亲的控件中我删除了OnApplyTemplate(),并在函数中SetBorderThickness()使用附加依赖属性的机会来设置值:

Father

// Removed
OnApplyTemplate() { ... }

// Add
Son.SetCellBorderThickness(childControl, value);

以下是一个完整的例子.结构示例:

XAML

Styles

儿子

<Style TargetType="{x:Type SonNamespace:Son}">
    <Setter Property="Background" Value="Gainsboro" />
    <Setter Property="BorderBrush" Value="Black" />
    <Setter Property="Width" Value="100" />
    <Setter Property="Height" Value="100" />
    <Setter Property="HorizontalAlignment" Value="Left" />
    <Setter Property="HorizontalContentAlignment" Value="Center" />
    <Setter Property="VerticalContentAlignment" Value="Center" />

    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate>
                <Border Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding SonNamespace:Son.CellBorderThickness}">

                    <ContentPresenter Content="I'am a Son" 
                                      HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                      VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

父亲

<Style TargetType="{x:Type FatherNamespace:Father}">
    <Setter Property="Background" Value="AliceBlue" />
    <Setter Property="BorderBrush" Value="Black" />
    <Setter Property="Width" Value="100" />
    <Setter Property="Height" Value="100" />
    <Setter Property="HorizontalAlignment" Value="Right" />
    <Setter Property="HorizontalContentAlignment" Value="Center" />
    <Setter Property="VerticalContentAlignment" Value="Center" />

    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate>
                <Border Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding SonNamespace:Son.CellBorderThickness}">

                    <ContentPresenter Content="I'am a Father" 
                                      HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                      VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

主窗口

<Grid>
    <SonNamespace:Son />

    <FatherNamespace:Father SonNamespace:Son.CellBorderThickness="6" />
</Grid>

Code

儿子

public class Son : Control
{
    public static readonly DependencyProperty CellBorderThicknessProperty =
                                              DependencyProperty.RegisterAttached("CellBorderThickness",
                                              typeof(Thickness), typeof(Son),
                                              new FrameworkPropertyMetadata(new Thickness(2),
                                                                            FrameworkPropertyMetadataOptions.AffectsRender,
                                                                            CellBorderThicknessProperty_ChangedCallBack));

    public static void SetCellBorderThickness(UIElement obj, Thickness value)
    {
        obj.SetValue(Son.CellBorderThicknessProperty, value);
    }

    public static Thickness GetCellBorderThickness(UIElement obj)
    {
        return (Thickness)obj.GetValue(Son.CellBorderThicknessProperty);
    }

    private static void CellBorderThicknessProperty_ChangedCallBack(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        Father father = d as Father;

        if (father != null)
        {
            father.SetBorderThickness((Thickness)e.NewValue);
        }
    }
}    

父亲

public class Father : Control
{
    private Son childControl; 

    public void SetBorderThickness(Thickness value)
    {
        if (childControl != null)
        {
            Son.SetCellBorderThickness(childControl, value);
        }
    }
}

Output

项目可在此链接中找到.