如何在 DataTrigger 中切换 TextBlock 的可见性? [英] How can I toggle a TextBlock's visibility in a DataTrigger?

问题描述

此代码有效(当 ControlType="dropDown" 然后背景黄色):

This code works (when ControlType="dropDown" then the background yellow):

<Window x:Class="TestCollapsed.Views.MainView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:c="clr-namespace:TestCollapsed.Commands"
    Title="Main Window" Height="400" Width="800">
    <Window.Resources>
        <Style x:Key="DropDownStyle" TargetType="TextBlock">
            <Style.Triggers>
                <DataTrigger Binding="{Binding ControlType}" Value="dropDown">
                    <Setter Property="Background" Value="Yellow"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>

    <StackPanel>
        <TextBlock Visibility="Visible" 
                   Text="This is going to be the dropdown control."
                   Style="{StaticResource DropDownStyle}"/>
    </StackPanel>
</Window>

但是这段代码不起作用(当 ControlType="dropDown" 时 TextBlock 仍然不可见):

But this code does not work (when ControlType="dropDown" then the TextBlock is still invisible):

<Window x:Class="TestCollapsed.Views.MainView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:c="clr-namespace:TestCollapsed.Commands"
    Title="Main Window" Height="400" Width="800">
    <Window.Resources>
        <Style x:Key="DropDownStyle" TargetType="TextBlock">
            <Style.Triggers>
                <DataTrigger Binding="{Binding ControlType}" Value="dropDown">
                    <Setter Property="Visibility" Value="Visible"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>

    <StackPanel>
        <TextBlock Visibility="Collapsed" 
                   Text="This is going to be the dropdown control."
                   Style="{StaticResource DropDownStyle}"/>
    </StackPanel>
</Window>

为什么我不能像设置背景那样在样式中设置可见性?

推荐答案

您正在 TextBlock 上设置 Visibility，然后尝试使用样式覆盖它.那行不通.试试这个:

You're setting the Visibility on the TextBlock and then trying to override it with a style. That won't work. Try this:

<Window x:Class="TestCollapsed.Views.MainView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:c="clr-namespace:TestCollapsed.Commands"
    Title="Main Window" Height="400" Width="800">
    <Window.Resources>
        <Style x:Key="DropDownStyle" TargetType="TextBlock">
            <Setter Property="Visibility" Value="Collapsed"/>
            <Style.Triggers>
                <DataTrigger Binding="{Binding ControlType}" Value="dropDown">
                    <Setter Property="Visibility" Value="Visible"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>

    <StackPanel>
        <TextBlock Text="This is going to be the dropdown control."
                   Style="{StaticResource DropDownStyle}"/>
    </StackPanel>
</Window>

这篇关于如何在 DataTrigger 中切换 TextBlock 的可见性?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！