WPF ListBox触发器不适用于IsFocused属性 [英] WPF ListBox Trigger not working for IsFocused Property

问题描述

我想为我的 ListBox 设置样式，并在其周围显示 Border 。我想在 ListBox 获得焦点时隐藏 Border ：



I want to style my ListBox and display a Border around it. I want to hide this Border when ListBox gets focus:

<Trigger Property="IsFocused" Value="True">
    <Setter Property="Visibility" TargetName="border" Value="Collapsed"/>
</Trigger>

我在 TextBox 而且它正在正常工作。
为什么 Trigger 不适用于 ListBox ？

Same thing I'm using in TextBox also and it is working properly. Why is this Trigger not working for ListBox?

编辑

我的样式 c $ c> ListBox ：

I am having this Style for my ListBox:

<ControlTemplate TargetType="{x:Type local:ListBox}">
    <Border SnapsToDevicePixels="true" x:Name="Bd" CornerRadius="5"
            Background="{TemplateBinding Background}"
            BorderBrush="{TemplateBinding BorderBrush}"
            BorderThickness="{TemplateBinding BorderThickness}" Padding="1">
        <Grid>
            <local:ScrollViewer Focusable="false" Padding="{TemplateBinding Padding}">
                <ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
            </local:ScrollViewer>
            <Border CornerRadius="5" Background="Red" x:Name="border">
                <TextBlock VerticalAlignment="Center" FontWeight="Bold" Foreground="White"
                           Text="{TemplateBinding Message}" FontFamily="Courier New" />
            </Border>
        </Grid>
    </Border>
</DockPanel>
    <ControlTemplate.Triggers>
        <Trigger Property="IsFocused" Value="True">
            <Setter Property="Visibility" TargetName="border" Value="Collapsed"/>
        </Trigger>
        <Trigger Property="IsEnabled" Value="false">
            <Setter Property="Background" TargetName="Bd"
                    Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
        </Trigger>
        <Trigger Property="IsGrouping" Value="true">
            <Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
        </Trigger>
    </ControlTemplate.Triggers>
</ControlTemplate>

推荐答案

对于ListBox IsFocused没有更新，因为焦点不去列表框，但它去的地方包括ListBox意味着ItemsPresenter其中包含ListBoxItems。我有一个解决这个问题的方法。
在ListBox的MouseDown事件处理程序中，我调用了Focus（）方法。它将IsFocused属性设置为true，并使触发器工作。

For ListBox IsFocused not updating because focus does not goes to list box but it goes to area covered by listbox means the ItemsPresenter which contains ListBoxItems. I have got a workaround to this problem. In MouseDown event handler of the ListBox, I call Focus() method. It sets the IsFocused property to true and make my trigger working.

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