具有行为的RadioButtons绑定到单个属性

Question

• 我有几个RadioButtons,我不想将它们中的每一个的"IsChecked"属性绑定到代码中的唯一属性.
• 我希望有一个像"CurrentSelected"这样的属性,并根据它来设置"IsChecked".
• 另外我不想使用转换器.

• 我试图使用行为"ChangePropertyAction",但它看起来只是以一种方式工作.这是我的代码:

  <RadioButton
      x:Name="UpRadioButton"
      Margin="5"
      Content="Up"
      >
      <i:Interaction.Triggers>
          <ei:DataTrigger Binding="{Binding IsChecked, ElementName=UpRadioButton}" Value="True">
              <ei:ChangePropertyAction TargetObject="{Binding Mode=OneWay}" PropertyName="SelectedDirection" Value="{x:Static Enums:DirectionEnum.Up}" />
          </ei:DataTrigger>
      </i:Interaction.Triggers>
  </RadioButton>
  
  <RadioButton
      x:Name="DownRadioButton"
      Margin="5"
      Content="Down"
      >
      <i:Interaction.Triggers>
          <ei:DataTrigger Binding="{Binding IsChecked, ElementName=DownRadioButton}" Value="True">
              <ei:ChangePropertyAction TargetObject="{Binding Mode=OneWay}" PropertyName="SelectedDirection" Value="{x:Static Enums:DirectionEnum.Down}" />
          </ei:DataTrigger>
      </i:Interaction.Triggers>
  </RadioButton>
  
  <RadioButton
      x:Name="LeftRadioButton"
      Margin="5"
      Content="Left"
      >
      <i:Interaction.Triggers>
          <ei:DataTrigger Binding="{Binding IsChecked, ElementName=LeftRadioButton}" Value="True">
              <ei:ChangePropertyAction TargetObject="{Binding Mode=OneWay}" PropertyName="SelectedDirection" Value="{x:Static Enums:DirectionEnum.Left}" />
          </ei:DataTrigger>
      </i:Interaction.Triggers>
  </RadioButton>
  
  <RadioButton
      x:Name="RightRadioButton"
      Margin="5"
      Content="Right"
      >
      <i:Interaction.Triggers>
          <ei:DataTrigger Binding="{Binding IsChecked, ElementName=RightRadioButton}" Value="True">
              <ei:ChangePropertyAction TargetObject="{Binding Mode=OneWay}" PropertyName="SelectedDirection" Value="{x:Static Enums:DirectionEnum.Right}" />
          </ei:DataTrigger>
      </i:Interaction.Triggers>
  </RadioButton>               
  

我的视图模型非常简单:MainViewModel.cs

public class MainViewModel : ViewModelBase
{ 
    private DirectionEnum _selectedDirection;

    public DirectionEnum SelectedDirection
    {
        get { return _selectedDirection; }
        set
        {
            if (_selectedDirection != value)
            {
                _selectedDirection = value;
                RaisePropertyChanged();
            }
        }
    }
    public MainViewModel()
    {     
        SelectedDirection = DirectionEnum.Up;            
    }  
}

从代码中可以看出,应该已经检查过"Up"RadioButton ......我错过了什么？

Answer 1

对我来说,一个常见的解决方案是使用包含选择行为的ListBox,并覆盖模板以将项目绘制为RadioButtons.

我的XAML模板通常看起来像这样:

<Style x:Key="RadioButtonListBoxStyle" TargetType="{x:Type ListBox}">
    <Setter Property="BorderBrush" Value="Transparent"/>
    <Setter Property="KeyboardNavigation.DirectionalNavigation" Value="Cycle" />
    <Setter Property="ItemContainerStyle">
        <Setter.Value>
            <Style TargetType="{x:Type ListBoxItem}" >
                <Setter Property="Margin" Value="2, 2, 2, 0" />
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate>
                            <Border Background="Transparent">
                                <RadioButton
                                    Content="{TemplateBinding ContentPresenter.Content}" VerticalAlignment="Center"
                                    IsChecked="{Binding Path=IsSelected,RelativeSource={RelativeSource TemplatedParent},Mode=TwoWay}"/>

                            </Border>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
        </Setter.Value>
    </Setter>
</Style>

样式应用如下:

<ListBox ItemsSource="{Binding Directions}"
         SelectedValue="{Binding SelectedDirection}"
         Style="{StaticResource RadioButtonListBoxStyle}" />

我发现管理分组RadioButton的选择行为比在代码隐藏或使用转换器中维护大量IsChecked属性要干净得多.