Xaml 如何防止选中单选按钮后不选中？

我有这样一个枚举：

public enum DLTypeEnum
{
    Others = 1, People = 2, Company = 4,
}

private DLTypeEnum _DLType;
public DLTypeEnum DLType
{
    get { return _DLType; }
    set { SetProperty(ref _DLType, value); }
}

我的ViewModel中有如下属性：

public enum DLTypeEnum
{
    Others = 1, People = 2, Company = 4,
}

private DLTypeEnum _DLType;
public DLTypeEnum DLType
{
    get { return _DLType; }
    set { SetProperty(ref _DLType, value); }
}

这是我的xaml：

选中RadioButton后，我不希望取消选中它，除非它选择了另一个RadioButton，即必须始终选择一个RadioButton。

请尝试以下代码：

<WrapPanel  Grid.Row="3" Grid.Column="1">
    <WrapPanel.Resources>
        <Converter:EnumToBoolConverter x:Key="EnumToBooleanConverter" />
    </WrapPanel.Resources>
    <RadioButton GroupName="DLType" IsChecked="{Binding Path=DLType,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged, Converter={StaticResource EnumToBooleanConverter}, ConverterParameter={x:Static dlAccount:DLTypeEnum.Others}}" Unchecked="RadioButton_Unchecked"/>
    <RadioButton GroupName="DLType" IsChecked="{Binding Path=DLType,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged, Converter={StaticResource EnumToBooleanConverter}, ConverterParameter={x:Static dlAccount:DLTypeEnum.People}}" Unchecked="RadioButton_Unchecked"/>
    <RadioButton GroupName="DLType" IsChecked="{Binding Path=DLType,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged, Converter={StaticResource EnumToBooleanConverter}, ConverterParameter={x:Static dlAccount:DLTypeEnum.Company}}" Unchecked="RadioButton_Unchecked"/>
 </WrapPanel>

---

除非我遗漏了什么，否则你只需要通过GroupName确定他们是一个组。我仍然有问题。

private void RadioButton_Unchecked(object sender, RoutedEventArgs e)
{
    if((_viewModel.DLss.CurrentItem as DL).DLType == 0)
      ((RadioButton)sender).IsChecked = true;
}