如何在DataTrigger中切换TextBlock的可见性？

Question

此代码有效 （当ControlType =“ dropDown”时背景为黄色 ）：

<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>

但是这个代码不工作（当ControlType =“下拉列表”，然后将TextBlock仍然是不可见的 ）：

<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>

为什么不能像设置背景一样设置可见性？

Answer 1

您要在TextBlock上设置“可见性”，然后尝试使用样式覆盖它。 那行不通。 尝试这个：

<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>

Answer 2

我也有同样的问题。 @Bryan的答案是完美的！ 有错误和正确的版本。 版本错误：

<TextBlock Text="1999-09-09 16:08" VerticalAlignment="Top" Visibility="Collapsed">
                                <TextBlock.Style>
                                    <Style BasedOn="{StaticResource TipTextYellow}" TargetType="TextBlock">
                                        <Style.Triggers>
                                            <DataTrigger Binding="{Binding ElementName=Alcohol,Path=IsFocused}"  Value="True">
                                                <Setter Property="Visibility" Value="Visible"/>
                                            </DataTrigger>
                                        </Style.Triggers>
                                    </Style>
                                </TextBlock.Style>
                            </TextBlock>

正确的版本：

<TextBlock Text="1999-09-09 16:08" VerticalAlignment="Top">
                                <TextBlock.Style>
                                    <Style BasedOn="{StaticResource TipTextYellow}" TargetType="TextBlock">
                                        <Setter Property="Visibility" Value="Collapsed"/>
                                        <Style.Triggers>
                                            <DataTrigger Binding="{Binding ElementName=Alcohol,Path=IsFocused}"  Value="True">
                                                <Setter Property="Visibility" Value="Visible"/>
                                            </DataTrigger>
                                        </Style.Triggers>
                                    </Style>
                                </TextBlock.Style>
                            </TextBlock>