Question

我在这里做错了什么？

我尝试在背景为红色时更改TextBox的文本值。

我可以使用任何其他属性触发此触发器（例如，当Width = 123时，文本正在正确更改） - 所以它必须是我的＆＃34; Red＆＃34;值

我试过这种方式：

<Style TargetType="{x:Type TextBox}" x:Key="t">
    <Style.Triggers>
        <Trigger Property="Background">
            <Trigger.Value>
                <SolidColorBrush Color="Red"/>
            </Trigger.Value>
        </Trigger>

        <Trigger.Setters>
           <Setter Property="Text" Value="Haha! Red detected!"/>
        </Trigger.Setters>
        </Trigger>
    </Style.Triggers>
</Style>

那样

<Style TargetType="{x:Type TextBox}" x:Key="t">
    <Style.Triggers>
        <Trigger Property="Background" Value="Red"/>

        <Trigger.Setters>
           <Setter Property="Text" Value="Haha! Red detected!"/>
        </Trigger.Setters>
        </Trigger>
    </Style.Triggers>
</Style>

没有反应。

这里是xaml

<Window x:Class="WpfApplication3.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="{x:Type TextBox}" x:Key="t">
        <Style.Triggers>
            <Trigger Property="Background">
                <Trigger.Value>
                    <SolidColorBrush Color="Red"/>
                </Trigger.Value>
                <Trigger.Setters>
                    <Setter Property="Text" Value="It's working!"/>
                </Trigger.Setters>
            </Trigger>
        </Style.Triggers>
    </Style>
</Window.Resources>
<StackPanel>
    <TextBox x:Name="tb" Style="{StaticResource t}" Text="White background" Background="White"></TextBox>
    <Button Height="68" Content="ChangeBackground" Click="Button_Click"></Button>
</StackPanel>
</Window>

和代码隐藏

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication3
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        tb.Background = new SolidColorBrush(Colors.Red);
    }
}
}

Answer 1

Brush不会覆盖Equals，因此会通过引用进行比较，因此 Red 将始终等于 Red 。你需要比较颜色

<Style TargetType="{x:Type TextBox}" x:Key="t">
   <Style.Triggers>
      <DataTrigger Binding="{Binding RelativeSource={RelativeSource Self}, Path=Background.Color}" Value="Red">
         <Setter Property="Text" Value="Haha! Red detected!"/>
      </DataTrigger>
   </Style.Triggers>
</Style>

当backgroundColor = Red时，触发文本框的文本值会发生变化

1 个答案: