How to make a text box Visibility=Hidden with a trigger

问题

I seem to be having a hard time today. All I want to do is make a TextBox hidden of visible based on a bool value databound to the Window its hosted in.

What I have just won't compile and I don't understand why. Please help.

<TextBlock Grid.Column="2" Text="This order will be sent to accounting for approval" 
           Foreground="Red" VerticalAlignment="Center" FontWeight="Bold" Padding="5">
    <TextBlock.Style>
        <Style>
            <Style.Triggers>
                <DataTrigger Binding="{Binding Path=AllowedToSubmit}" Value="True">
                    <Setter Property="Visibility" Value="Hidden" /> 
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </TextBlock.Style>
</TextBlock>

回答1:

You need to set the Style.TargetType in order for it to recognize the Visibility property:

<TextBlock Grid.Column="2" VerticalAlignment="Center" FontWeight="Bold" Foreground="Red" Padding="5" Text="This order will be sent to accounting for approval">
    <TextBlock.Style>
        <Style TargetType="{x:Type TextBlock}">
            <Style.Triggers>
                <DataTrigger Binding="{Binding Path=AllowedToSubmit}" Value="True">
                    <Setter Property="Visibility" Value="Hidden"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </TextBlock.Style>
</TextBlock>

~~Your binding path to AllowedToSubmit probably needs to have ElementName set to the Window's name, as well.~~

回答2:

Another option is to bind TextBlock.Visibility directly to the property:

<Window>
    <Window.Resources>
        <BooleanToVisibilityConverter x:Key="BoolToVisibility" />
    </Window.Resources>
    <TextBlock Visibility="{Binding Path=AllowedToSubmit, Converter={StaticResource BoolToVisibility}}" />
</Window>

If you want it to work like in your sample, where true hides the TextBlock, then you can write your own converter to convert opposite of the built-in BooleanToVisibilityConverter.

来源：https://stackoverflow.com/questions/631098/how-to-make-a-text-box-visibility-hidden-with-a-trigger

标签

wpf

.net-3.5

styles

datatrigger