WPF TextBox触发器清除文本 [英] WPF TextBox trigger to clear Text

问题描述

我有很多 TextBox 控件，我正在尝试编写一种清除Text 属性何时的样式该控件被禁用。
我不想在代码中包含事件处理程序。

I have many TextBox controls and I'm trying to write a style that clears the Text property when the Control is disabled. I don't want to have Event Handlers in code behind.

我这样写：

<Style TargetType="{x:Type TextBox}">                            
 <Style.Triggers>
  <Trigger Property="IsEnabled" Value="False">                                    
   <Setter Property="Text" Value="{x:Null}" />
  </Trigger>                                
 </Style.Triggers>
</Style>

问题在于，如果TextBox的定义如下：

The problem is that if the TextBox is defined like:

<TextBox Text={Binding Whatever} />

然后触发器不起作用（可能是因为它绑定了）
如何克服此问题？

then the trigger does not work (probably because it's bound) How to overcome this problem?

推荐答案

由于要在TextBox中显式设置Text，因此样式的触发器无法覆盖它。试试这个：

Because you're explicitly setting the Text in the TextBox, the style's trigger can't overwrite it. Try this:

<TextBox>
    <TextBox.Style>
        <Style TargetType="{x:Type TextBox}">
            <Setter Property="Text" Value="{Binding Whatever}" />

            <Style.Triggers>
                <Trigger Property="IsEnabled" Value="False">
                    <Setter Property="Text" Value="{x:Null}" /> 
                </Trigger>
            </Style.Triggers>
        </Style> 
    </TextBox.Style>
</TextBox>

这篇关于WPF TextBox触发器清除文本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！