Question

我有几个从DockPanel，ToggleButton，ComboBox等派生的自定义控件。我有一个类Props，我想在每个派生类中用作依赖属性。所有这些类都需要具有相同的依赖属性（包含在Props中），并且可能具有自己的几个独特属性（例如，仅在Dock Panel中）。示例用例是属性ExistsInConfig和RightVisible。我希望控件只有在两者都设置为true时才可见。这个逻辑应该可以在我的所有自定义派生控件中使用。

DockPanel.cs：

public class DockPanel : System.Windows.Controls.DockPanel
{
    public DockPanel()
    {
        Props = new Props();
    }

    public Props Props
    {
        get
        {
            return (Props)GetValue(Properties);
        }
        set
        {
            SetValue(Properties, value);
        }
    }

    public static readonly DependencyProperty Properties =
    DependencyProperty.Register("Props", typeof(Props), typeof(DockPanel), new PropertyMetadata(null));
}

Props.cs：

public class Props: DependencyObject
{
    public Props(){}

    public bool RightVisible { get; set;}

    public bool ExistsInConfig { get; set; }

    public static readonly DependencyProperty RightVisibleProperty =
    DependencyProperty.Register("RightVisible", typeof(bool), typeof(Props), new FrameworkPropertyMetadata(true, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault));

    public static readonly DependencyProperty ExistsInConfigProperty =
    DependencyProperty.Register("ExistsInConfig", typeof(bool), typeof(Props), new FrameworkPropertyMetadata(true, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault));

    public static bool GetExistsInConfig(DependencyObject obj)
    {
        return (bool)obj.GetValue(ExistsInConfigProperty);
    }

    public static void SetExistsInConfig(DependencyObject obj, bool value)
    {
       obj.SetValue(ExistsInConfigProperty, value);
    }

    public static bool GetRightVisible(DependencyObject obj)
    {
        return (bool)obj.GetValue(RightVisibleProperty);
    }

    public static void SetRightVisible(DependencyObject obj, bool value)
    {
        obj.SetValue(RightVisibleProperty, value);
    }
}

DockPanel的样式：

<Style x:Key="CustomDockPanelStyle" TargetType="custom:DockPanel">
    <Setter Property="Visibility">
        <Setter.Value>
            <MultiBinding Converter="{StaticResource MultipleBooleanToVisibilityConverter}">
                <Binding RelativeSource="{RelativeSource Self}" Path="Props.ExistsInConfig" NotifyOnSourceUpdated="True" NotifyOnTargetUpdated="True" UpdateSourceTrigger="PropertyChanged"/>
                <Binding RelativeSource="{RelativeSource Self}" Path="Props.RightVisible" NotifyOnSourceUpdated="True" NotifyOnTargetUpdated="True" UpdateSourceTrigger="PropertyChanged" />
            </MultiBinding>
        </Setter.Value>
    </Setter>
</Style>

在XAML中使用控件：

<Window.Resources>
    <Style TargetType="{x:Type custom:DockPanel}" BasedOn={StaticResource CustomDockPanelStyle}"
</Window.Resources>

<custom:DockPanel 
custom:Props.ExistsInConfig="{Binding ElementName=ToggleCombinedVisibility, Path=IsChecked, Mode=OneWay, NotifyOnTargetUpdated=True, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}" 
custom:Props.RightVisible="{Binding ElementName=ToggleCombinedVisibility, Path=IsChecked, Mode=OneWay, NotifyOnTargetUpdated=True, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}">

<ToggleButton x:Name="ToggleCombinedVisibility" IsChecked="True" />

问题是，绑定不起作用。 MultipleBooleanToVisibilityConverter仅在加载视图时调用，而不是在我尝试使用按钮切换可见性时调用。如果我在RightVisible和ExistsInConfig的PropertyMetadata中指定回调，则在切换按钮后会调用它们，但转换器不会。

我是否必须让DockPanel知道Props已更改？我该怎么做？我无法找到在两个类中实现INotifyPropertyChanged的方法。

Answer 1

Style中的绑定路径错误。

附加属性应该用括号和自定义附加属性包围，并且应该在命名空间别名之前。

这应该有效：

<Style x:Key="CustomDockPanelStyle" TargetType="custom:DockPanel">
    <Setter Property="Visibility">
        <Setter.Value>
            <MultiBinding Converter="{StaticResource MultipleBooleanToVisibilityConverter}">
                <Binding RelativeSource="{RelativeSource Self}" Path="(custom:Props.ExistsInConfig)" NotifyOnSourceUpdated="True" NotifyOnTargetUpdated="True" UpdateSourceTrigger="PropertyChanged"/>
                <Binding RelativeSource="{RelativeSource Self}" Path="(custom:Props.RightVisible)" NotifyOnSourceUpdated="True" NotifyOnTargetUpdated="True" UpdateSourceTrigger="PropertyChanged" />
            </MultiBinding>
        </Setter.Value>
    </Setter>
</Style>

绑定到自定义控件的嵌套依赖项属性

1 个答案: