WPF 可见性绑定(bind)到具有多个变量的 bool 表达式

Question

我有两个 bool 值，我想根据它们的值显示图像，如下所示:

   <Window.Resources>
    <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
</Window.Resources>

<Image Visibility="{Binding (Boolean1 && Boolean2),Converter={StaticResource BooleanToVisibilityConverter}}" />

注意 Boolean1 和 Boolean2 表达式。

Answer 1

XAML 中没有定义 && 运算符，但您可以绑定(bind)到多个属性并使用 IMultiValueConverter:

<Image>
    <Image.Visibility>
        <MultiBinding Converter="{StaticResource YourMultiConverter}">
            <Binding Path="Boolean1" />
            <Binding Path="Boolean2" />
        </MultiBinding>
    </Image.Visibility>
</Image>

<小时/>

public class YourMultiValueConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        bool a = (bool)values[0];
        bool b = (bool)values[1];

        return a && b ? Visibility.Visible : Visibility.Collapsed;
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

或者您可以使用带条件的 Image 样式:

<Image>
    <Image.Style>
        <Style TargetType="Image">
            <Setter Property="Visibility" Value="Collapsed" />
            <Style.Triggers>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding Boolean1}" Value="True" />
                        <Condition Binding="{Binding Boolean2}" Value="True" />
                    </MultiDataTrigger.Conditions>
                    <Setter Property="Visibility" Value="Visible" />
                </MultiDataTrigger>
            </Style.Triggers>
        </Style>
    </Image.Style>
</Image>