Wpf 如何基于文本框值绑定控件（StackPanel）的可见性？

在WPF MVVM应用程序中，我有一个

TextBox

TxtFruit

和两个

StackPanel

s

stackPanelApple

和

stackPanelOrange

这就是应该发生的事情：

• 如果

  txtFruit.Text

  是“Apple”，则

  stackPanelApple

  将可见
• 如果

  txtFruit.Text

  更改为“橙色”，则将显示

  stackPanelOrange

• 如果

  txtFruit.Text

  为空或其他内容，则面板的

  可见性

  应为

  折叠

如何在视图模型中实现这一点

<TextBox x:Name="TxtFruit" Text="{Binding CurrentFruit}"/>
<StackPanel>
   <StackPanel x:Name="stackPanelApple" Orientation="Horizontal" Margin="0,0,0,20" >
      <TextBox x:Name="AppleProperty1" Margin="0,0,10,0" Text="{Binding AppleProperty1}" />
      <TextBox x:Name="AppleProperty2" Margin="10,0,10,0" Text="{Binding AppleProperty2}" />
   </StackPanel>
   <StackPanel x:Name="stackPanelOrange" Orientation="Horizontal" Margin="0,0,0,20" >
      <TextBox x:Name="OrangeProperty1" Margin="0,0,10,0" Text="{Binding OrangeProperty1}" />
      <TextBox x:Name="OrangeProperty1" Margin="10,0,10,0" Text="{Binding OrangeProperty2}"/>
   </StackPanel>

---

您可以使用XAML视图中的样式和触发器执行此操作：

<TextBox x:Name="TxtFruit" Text="{Binding CurrentFruit}"/>
<StackPanel>
    <StackPanel x:Name="stackPanelApple" Orientation="Horizontal" Margin="0,0,0,20" >
        <TextBox x:Name="AppleProperty1" Margin="0,0,10,0" Text="{Binding AppleProperty1}" />
        <TextBox x:Name="AppleProperty2" Margin="10,0,10,0" Text="{Binding AppleProperty2}" />
        <StackPanel.Style>
            <Style TargetType="StackPanel">
                <Setter Property="Visibility" Value="Collapsed" />
                <Style.Triggers>
                    <DataTrigger Binding="{Binding Text, ElementName=TxtFruit}" Value="Apple">
                        <Setter Property="Visibility" Value="Visible" />
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </StackPanel.Style>
    </StackPanel>
    <StackPanel x:Name="stackPanelOrange" Orientation="Horizontal" Margin="0,0,0,20" >
        <TextBox x:Name="OrangeProperty1" Margin="0,0,10,0" Text="{Binding OrangeProperty1}" />
        <TextBox x:Name="OrangeProperty2" Margin="10,0,10,0" Text="{Binding OrangeProperty2}"/>
        <StackPanel.Style>
            <Style TargetType="StackPanel">
                <Setter Property="Visibility" Value="Collapsed" />
                <Style.Triggers>
                    <DataTrigger Binding="{Binding Text, ElementName=TxtFruit}" Value="Orange">
                        <Setter Property="Visibility" Value="Visible" />
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </StackPanel.Style>
    </StackPanel>
</StackPanel>

---

您可以使用XAML视图中的样式和触发器执行此操作：

<TextBox x:Name="TxtFruit" Text="{Binding CurrentFruit}"/>
<StackPanel>
    <StackPanel x:Name="stackPanelApple" Orientation="Horizontal" Margin="0,0,0,20" >
        <TextBox x:Name="AppleProperty1" Margin="0,0,10,0" Text="{Binding AppleProperty1}" />
        <TextBox x:Name="AppleProperty2" Margin="10,0,10,0" Text="{Binding AppleProperty2}" />
        <StackPanel.Style>
            <Style TargetType="StackPanel">
                <Setter Property="Visibility" Value="Collapsed" />
                <Style.Triggers>
                    <DataTrigger Binding="{Binding Text, ElementName=TxtFruit}" Value="Apple">
                        <Setter Property="Visibility" Value="Visible" />
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </StackPanel.Style>
    </StackPanel>
    <StackPanel x:Name="stackPanelOrange" Orientation="Horizontal" Margin="0,0,0,20" >
        <TextBox x:Name="OrangeProperty1" Margin="0,0,10,0" Text="{Binding OrangeProperty1}" />
        <TextBox x:Name="OrangeProperty2" Margin="10,0,10,0" Text="{Binding OrangeProperty2}"/>
        <StackPanel.Style>
            <Style TargetType="StackPanel">
                <Setter Property="Visibility" Value="Collapsed" />
                <Style.Triggers>
                    <DataTrigger Binding="{Binding Text, ElementName=TxtFruit}" Value="Orange">
                        <Setter Property="Visibility" Value="Visible" />
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </StackPanel.Style>
    </StackPanel>
</StackPanel>

---

在视图模型中不需要执行此操作。您可以使用样式中的数据触发器来解决此问题，例如：

<Style TargetType="{x:Type StackPanel}">
   <Setter Property="Visibility" Value="Collapsed"/>
   <Style.Triggers>
      <DataTrigger Binding="{Binding Text, ElementName=TxtFruit}" Value="Apple">
         <Setter Property="Visibility" Value="Visible"/>
      </DataTrigger>
   </Style.Triggers>
</Style>

在任何资源中创建转换器的实例，例如在应用程序资源字典中

<local:EqualityToVisibilityConverter x:Key="EqualityToVisibilityConverter"/>

然后，您可以轻松地重用转换器来绑定可见性，而无需样式

<TextBox x:Name="TxtFruit" Text="{Binding CurrentFruit}"/>
<StackPanel>
   <StackPanel x:Name="stackPanelApple" Orientation="Horizontal" Margin="0,0,0,20"
               Visibility="{Binding Text, ElementName=TxtFruit, Converter={StaticResource EqualityToVisibilityConverter}, ConverterParameter=Apple}">
      <TextBox x:Name="AppleProperty1" Margin="0,0,10,0" Text="{Binding AppleProperty1}"/>
      <TextBox x:Name="AppleProperty2" Margin="10,0,10,0" Text="{Binding AppleProperty2}"/>
   </StackPanel>
   <StackPanel x:Name="stackPanelOrange" Orientation="Horizontal" Margin="0,0,0,20"
               Visibility="{Binding Text, ElementName=TxtFruit, Converter={StaticResource EqualityToVisibilityConverter}, ConverterParameter=Orange}">
      <TextBox x:Name="OrangeProperty1" Margin="0,0,10,0" Text="{Binding OrangeProperty1}"/>
      <TextBox x:Name="OrangeProperty1" Margin="10,0,10,0" Text="{Binding OrangeProperty2}"/>
   </StackPanel>
</StackPanel>

---

在视图模型中不需要执行此操作。您可以使用样式中的数据触发器来解决此问题，例如：

<Style TargetType="{x:Type StackPanel}">
   <Setter Property="Visibility" Value="Collapsed"/>
   <Style.Triggers>
      <DataTrigger Binding="{Binding Text, ElementName=TxtFruit}" Value="Apple">
         <Setter Property="Visibility" Value="Visible"/>
      </DataTrigger>
   </Style.Triggers>
</Style>

在任何资源中创建转换器的实例，例如在应用程序资源字典中

<local:EqualityToVisibilityConverter x:Key="EqualityToVisibilityConverter"/>

然后，您可以轻松地重用转换器来绑定可见性，而无需样式

<TextBox x:Name="TxtFruit" Text="{Binding CurrentFruit}"/>
<StackPanel>
   <StackPanel x:Name="stackPanelApple" Orientation="Horizontal" Margin="0,0,0,20"
               Visibility="{Binding Text, ElementName=TxtFruit, Converter={StaticResource EqualityToVisibilityConverter}, ConverterParameter=Apple}">
      <TextBox x:Name="AppleProperty1" Margin="0,0,10,0" Text="{Binding AppleProperty1}"/>
      <TextBox x:Name="AppleProperty2" Margin="10,0,10,0" Text="{Binding AppleProperty2}"/>
   </StackPanel>
   <StackPanel x:Name="stackPanelOrange" Orientation="Horizontal" Margin="0,0,0,20"
               Visibility="{Binding Text, ElementName=TxtFruit, Converter={StaticResource EqualityToVisibilityConverter}, ConverterParameter=Orange}">
      <TextBox x:Name="OrangeProperty1" Margin="0,0,10,0" Text="{Binding OrangeProperty1}"/>
      <TextBox x:Name="OrangeProperty1" Margin="10,0,10,0" Text="{Binding OrangeProperty2}"/>
   </StackPanel>
</StackPanel>

这就像一个符咒。但我需要一个更像非xaml的解决方案。太谢谢你了，这很有魅力。但我需要一个更像非xaml的解决方案。非常感谢，太棒了！使用

数据触发器

可以。但我还是坚持使用

值转换器
方法。我非常感谢你的帮助。太棒了！使用
数据触发器
可以。但我还是坚持使用
值转换器
方法。我非常感谢你的帮助。