c# - WPF 中的数据触发条件检查

Question

是否可以在 DataTrigger 上给出条件？

<DataTrigger Binding="{Binding MessageBoxImage}" Value="{x:Static MessageBoxImage.Error}">
    <Setter Property="Source" Value="../Images/Error48.png"></Setter>
</DataTrigger>
<DataTrigger Binding="{Binding MessageBoxImage}" Value="{x:Static MessageBoxImage.Hand}">
    <Setter Property="Source" Value="../Images/Error48.png"></Setter>
</DataTrigger>
<DataTrigger Binding="{Binding MessageBoxImage}" Value="{x:Static MessageBoxImage.Stop}">
    <Setter Property="Source" Value="../Images/Error48.png"></Setter>
</DataTrigger>

所以，这是我的 Xaml 代码，在那个 Error、Hand、Stop 中都设置了相同的图像

我的问题是可以为这三个值给出 OR 条件吗？ (或一行语句)

谢谢，

Answer 1

您可以使用 MultiDataTrigger对于 AND 条件。至于 OR 条件，您可以使用转换器。

<Window.Resources>
   <someNs:ORConverter x:Key = "ORConverter"/>
</Window.Resources>

....

<DataTrigger Value="True">
   <DataTrigger.Binding>
        <Binding Path="MessageBoxImage" Converter="{StaticResource ORConverter}">
            <Binding.ConverterParameter>
                <x:Array Type="MessageBoxImage">
                     <x:Static MemberType="MessageBoxImage" Member="Error" />
                     <x:Static MemberType="MessageBoxImage" Member="Information" />
                     <x:Static MemberType="MessageBoxImage" Member="Question" />
                </x:Array>
            </Binding.ConverterParameter>
        </Binding>
   </DataTrigger.Binding>

   <Setter Property="Source" Value="../Images/Error48.png"></Setter>
</DataTrigger>

和转换器的代码:

public class ORConverter : IValueConverter
{
    public object Convert(object value, Type targetType, 
           object parameter, System.Globalization.CultureInfo culture)
    {
         var list = parameter as IList;
         if (list == null)
             return false;

         foreach (var o in list)
         {
             if (Equals(o, value))
                return true;
         }

         return false;
    }

    public object ConvertBack(object value, Type targetType, 
           object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotSupportedException("Cannot convert back");
    }
}