获取ItemsControl子项以在WinRT中继承前景

您尝试过{TemplateBinding xxxx}吗?

<Controls:MyCustomControl MyCustomForeground="{TemplateBinding Foreground}">
    <Controls:MyCustomControl.PrimaryItems>
        <Button Content="Test button"/>
    </Controls:MyCustomControl.PrimaryItems>
</Controls:MyCustomControl>

我明白了,这个很棘手。如果您尝试使用DependencyProperty继承,这将不起作用(使用UserControl的前台属性):

<UserControl
    x:Class="TestApp1.CustomControl"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:TestApp1"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="300"
    d:DesignWidth="400" Foreground="Blue">

    <StackPanel x:Name="PART_Container">
        <Button Content="Test"/>
        <TextBlock Text="Test"/>
    </StackPanel>
</UserControl>

如果您尝试此片段,手机的按钮模板将覆盖前景=“蓝色”,因此它将具有白色(或黑色,取决于主题)前景。请注意,Textblock未设置样式,不会显示此行为,它将成功从其父UserControl继承蓝色前景。

如何绕过这个?您似乎声明了自定义依赖属性MyCustomForeground,因此可以在DependencyPropertyChanged处理程序中实现逻辑。但每次PrimaryItems更改时,您也必须应用自定义前景。

这是一个工作示例:

public sealed partial class CustomControl : UserControl
{
    public CustomControl()
    {
        this.InitializeComponent();
    }
    public Brush MyCustomForeground
    {
        get { return (Brush)GetValue(MyCustomForegroundProperty); }
        set { SetValue(MyCustomForegroundProperty, value); }
    }

    // Using a DependencyProperty as the backing store for MyCustomForeground.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty MyCustomForegroundProperty =
        DependencyProperty.Register("MyCustomForeground", typeof(Brush), typeof(CustomControl), new PropertyMetadata(null, OnCustomForegroundChanged));

    private static void OnCustomForegroundChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        CustomControl ctrl = (CustomControl)d;
        ctrl.ApplyCustomForeground();
    }

    public UIElement PrimaryItems
    {
        get { return (UIElement)GetValue(PrimaryItemsProperty); }
        set { SetValue(PrimaryItemsProperty, value); }
    }

    // Using a DependencyProperty as the backing store for PrimaryItems.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty PrimaryItemsProperty =
        DependencyProperty.Register("PrimaryItems", typeof(UIElement), typeof(CustomControl), new PropertyMetadata(null, OnPrimaryItemsChanged));

    private static void OnPrimaryItemsChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        CustomControl ctrl = (CustomControl)d;
        // PART_Container is where I store my PrimaryItems
        ctrl.PART_Container.Children.Clear();
        ctrl.PART_Container.Children.Add((UIElement)e.NewValue);
        ctrl.ApplyCustomForeground();
    }

    private void ApplyCustomForeground()
    {
        // PART_Container is where I store my PrimaryItems
        foreach (var child in PART_Container.Children)
        {
            // Foreground is inherited by Control or TextBlock, or other classes... 
            // You would be better off using reflection here but that's off topic
            if (child is Control)
            {
                ((Control)child).Foreground = MyCustomForeground;
            }
            else if (child is TextBlock)
            {
                ((TextBlock)child).Foreground = MyCustomForeground;
            }
        }
    }
}