Question

为什么TextBlock保持黑色？

<Window x:Class="WpfApplication4.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <Style TargetType="TextBlock" x:Key="style">
            <Style.Triggers>
                <DataTrigger Binding="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Tag}" Value="True">
                    <Setter Property="Foreground" Value="Red" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>
    <StackPanel>
        <TextBlock Text="Test" Tag="True" Style="{StaticResource style}" />
    </StackPanel>
</Window>

更新：好了，现在我还有另外一个问题。风格对财产变化没有反应：

<Window x:Class="WpfApplication4.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <Style TargetType="TextBlock" x:Key="style">
            <Style.Triggers>
                <Trigger Property="Tag" Value="True">
                    <Setter Property="Foreground" Value="Red" />
                </Trigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>
    <StackPanel>
        <TextBlock Text="{Binding Prop}" Tag="{Binding Prop}" Style="{StaticResource style}" x:Name="text" />
        <Button Content="Test" Click="Button_Click" />
    </StackPanel>
</Window>

支持代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.ComponentModel;

namespace WpfApplication4
{
    public partial class MainWindow : Window
    {
        private MyClass a = new MyClass();

        public MainWindow()
        {
            InitializeComponent();
            DataContext = a;
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            a.Prop = true;
            a.OnPropertyChanged("Prop");
        }
    }

    public class MyClass : INotifyPropertyChanged
    {
        public bool Prop { get; set; }

        public event PropertyChangedEventHandler PropertyChanged;
        public virtual void OnPropertyChanged(string property)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(property));
        }
    }
}

TextBlock的文字发生了变化，但颜色不是

Answer 1

将其更改为Property Trigger

    <Style TargetType="TextBlock" x:Key="style">
        <Style.Triggers>
            <Trigger Property="Tag" Value="True">
                <Setter Property="Foreground" Value="Red" />
            </Trigger>
        </Style.Triggers>
    </Style>

TemplatedParent在ControlTemplate中运行。您的绑定不正确。这就是为什么它不起作用。

如果由于某种原因想要使用DataTrigger，那么正确的Binding将是

<DataTrigger Binding="{Binding Tag,RelativeSource={RelativeSource Self}}" Value="True">

Answer 2

只需更改装订：

Binding="{Binding RelativeSource={RelativeSource Self}, Path=Tag}"

Answer 3

这主要发生，因为Tag属性是object类型而不是string。以下链接中给出的解决方案可能对您有所帮助：

http://social.msdn.microsoft.com/forums/en-US/wpf/thread/d3424267-ed1f-4b30-90a1-5cca9843bd22

关于Textblock.Tag属性： http://msdn.microsoft.com/en-us/library/system.windows.frameworkelement.tag.aspx

为什么这种简单的风格不适用？

3 个答案: