WPF - IsEnabled 绑定到 DependencyProperty 无法正常工作

Question

我在窗口中定义了一个依赖属性，如下所示：

public static readonly DependencyProperty IsGenericUserProperty = DependencyProperty.Register("IsGenericUser", typeof (bool), typeof (MainWindow));
public bool IsGenericUser
{
    get { return (bool) GetValue(IsGenericUserProperty); }
    set { SetValue(IsGenericUserProperty, value); }
}

在窗口的构造函数上，我设置了包含按钮的容器的数据上下文：

QuickListButtonsStackPanel.DataContext = this;

我将依赖属性绑定到按钮的 IsEnabled 属性：

<Button IsEnabled="{Binding IsGenericUser}" .../>

启动时 IsGenericUser 为 true，因此按钮已启用。 当我将 IsGenericUser 设置为 false 时，该按钮将被禁用。 但是，如果我再次将 IsGenericUser 设置为 true，则该按钮不会发生任何变化，并且它仍然处于禁用状态。 我究竟做错了什么？

谢谢！

编辑： 这是我使用按钮的样式。 这种样式导致了问题（如果按钮没有自定义样式，则可以正常工作）：

<Style x:Key="BlackButtonStyle" TargetType="{x:Type Button}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Button}">
                <ControlTemplate.Resources>
                    <Storyboard x:Key="MouseOverActivating">
                        <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="rectangle" Storyboard.TargetProperty="(Shape.Fill).(GradientBrush.GradientStops)[1].(GradientStop.Color)">
                            <SplineColorKeyFrame KeyTime="00:00:00" Value="#FF2F2F2F"/>
                            <SplineColorKeyFrame KeyTime="00:00:00.1270000" Value="#FF2391FF"/>
                        </ColorAnimationUsingKeyFrames>
                    </Storyboard>
                    <Storyboard x:Key="MouseOverDeactivating">
                        <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="(Shape.Fill).(GradientBrush.GradientStops)[1].(GradientStop.Color)" Storyboard.TargetName="rectangle">
                            <SplineColorKeyFrame KeyTime="00:00:00" Value="#FF2391FF"/>
                            <SplineColorKeyFrame KeyTime="00:00:00.2200000" Value="#FF2F2F2F"/>

                        </ColorAnimationUsingKeyFrames>
                    </Storyboard>
                    <Storyboard x:Key="PressActivating">
                        <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="rectangle" Storyboard.TargetProperty="(Shape.Fill).(GradientBrush.GradientStops)[1].(GradientStop.Color)">
                            <SplineColorKeyFrame KeyTime="00:00:00" Value="#FF2391FF"/>
                            <SplineColorKeyFrame KeyTime="00:00:00.1370000" Value="#FF48D6FF"/>
                        </ColorAnimationUsingKeyFrames>
                    </Storyboard>
                    <Storyboard x:Key="PressedDeactivating" FillBehavior="Stop" >
                        <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="(Shape.Fill).(GradientBrush.GradientStops)[1].(GradientStop.Color)" Storyboard.TargetName="rectangle">
                            <SplineColorKeyFrame KeyTime="00:00:00" Value="#FF48D6FF"/>
                            <SplineColorKeyFrame KeyTime="00:00:00.2370000" Value="#FF2391FF"/>
                        </ColorAnimationUsingKeyFrames>
                    </Storyboard>
                    <Storyboard x:Key="DisableActivating">
                        <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="rectangle" Storyboard.TargetProperty="(Shape.Fill).(GradientBrush.GradientStops)[1].(GradientStop.Color)">
                            <SplineColorKeyFrame KeyTime="00:00:00" Value="#FFA7A7A7"/>
                        </ColorAnimationUsingKeyFrames>
                    </Storyboard>
                </ControlTemplate.Resources>
                <Grid>
                    <Rectangle Stroke="Transparent" RadiusX="5" RadiusY="5" x:Name="rectangle">
                        <Rectangle.Fill>
                            <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                <GradientStop Color="#FF000000" Offset="0"/>
                                <GradientStop Color="#FF2F2F2F" Offset="1"/>
                            </LinearGradientBrush>
                        </Rectangle.Fill>
                    </Rectangle>
                    <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" RecognizesAccessKey="True" OpacityMask="{x:Null}"/>
                    <Rectangle Stroke="Transparent" RadiusX="5" RadiusY="5" x:Name="WhiteGlow">
                        <Rectangle.Fill>
                            <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                <GradientStop Color="#5BFFFFFF" Offset="0"/>
                                <GradientStop Color="#00FFFFFF" Offset="0.5"/>
                            </LinearGradientBrush>
                        </Rectangle.Fill>
                    </Rectangle>
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsCancel" Value="False"/>
                    <EventTrigger RoutedEvent="FrameworkElement.Loaded"/>
                    <Trigger Property="IsFocused" Value="True">
                        <Trigger.ExitActions>
                            <BeginStoryboard Storyboard="{StaticResource MouseOverActivating}" x:Name="MouseOverActivating_BeginStoryboard2"/>
                        </Trigger.ExitActions>
                        <Trigger.EnterActions>
                            <BeginStoryboard Storyboard="{StaticResource MouseOverActivating}" x:Name="MouseOverActivating_BeginStoryboard1"/>
                        </Trigger.EnterActions>
                    </Trigger>
                    <Trigger Property="IsDefaulted" Value="True"/>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Trigger.ExitActions>
                            <BeginStoryboard Storyboard="{StaticResource MouseOverDeactivating}" x:Name="MouseOverDeactivating_BeginStoryboard"/>
                        </Trigger.ExitActions>
                        <Trigger.EnterActions>
                            <BeginStoryboard Storyboard="{StaticResource MouseOverActivating}" x:Name="MouseOverActivating_BeginStoryboard"/>
                        </Trigger.EnterActions>
                    </Trigger>
                    <Trigger Property="IsPressed" Value="True">
                        <Trigger.EnterActions>
                            <BeginStoryboard x:Name="PressActivating_BeginStoryboard" Storyboard="{StaticResource PressActivating}"/>
                        </Trigger.EnterActions>
                        <Trigger.ExitActions>
                            <BeginStoryboard x:Name="PressedDeactivating_BeginStoryboard" Storyboard="{StaticResource PressedDeactivating}"/>
                        </Trigger.ExitActions>
                    </Trigger>
                    <Trigger Property="IsEnabled" Value="False">
                        <Trigger.EnterActions>
                            <BeginStoryboard Storyboard="{StaticResource DisableActivating}" x:Name="DisableActivating_BeginStoryboard"/>
                        </Trigger.EnterActions>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Answer 1

您如何将该属性设置为 False/True？ 如果我按原样复制您的代码，它会完美运行。 必须有其他你可能意想不到的事情发生，比如按钮上的动画或清除绑定的东西。 您是否可以发布更多代码来帮助阐明可能执行此操作的原因？

这也是我测试过的代码：

<Window x:Class="WpfApplication6.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1"
    Height="300"
    Width="300">
<Grid>
    <StackPanel x:Name="QuickListButtonsStackPanel">
        <Button IsEnabled="{Binding IsGenericUser}"
                Content="Bound Button" />
        <Button Content="Change Binding"
                Click="Button_Click" />
    </StackPanel>
</Grid>

public partial class Window1 : Window
{
    public Window1()
    {
        InitializeComponent();
        QuickListButtonsStackPanel.DataContext = this;
    }
    public static readonly DependencyProperty IsGenericUserProperty =
        DependencyProperty.Register(
            "IsGenericUser",
            typeof(bool),
            typeof(Window1));

    public bool IsGenericUser
    {
        get { return (bool)GetValue(IsGenericUserProperty); }
        set { SetValue(IsGenericUserProperty, value); }
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        IsGenericUser = !IsGenericUser;
    }
}

编辑：
您还可以添加一个文本框来查看它是否正常工作，

<Button x:Name="uiButton"
        IsEnabled="{Binding IsGenericUser}"
        Style="{StaticResource BlackButtonStyle}"
        Content="Bound Button"/>
<TextBlock Text="{Binding ElementName=uiButton, Path=IsEnabled}" />

看起来问题只是样式的故事板，如果您添加它，它是否仍然显示 IsEnabled 为 false，而它不应该是 false？

Answer 2

尝试

<Button IsEnabled={Binding Path=IsGenericUser}" ... />

Path= 不应该是必需的，但它可能会有所不同。

通过在数据上下文中使用 this，您确定这是正确的吗？ 这不会使控件本身适应上下文吗？ 我还没有看到你的其余代码，但这似乎不对。

Answer 3

1）创建一个名为DisableDeactivating的新故事板并设置FillBehavior =“Stop”（尼古拉斯的建议）
2）然后，在IsEnabled = false触发器的Trigger.ExitActions中添加一个用于DisableDeactivating的BeginStoryboard。

Answer 4

如果有人遇到同样的问题 - 很可能您的 DataContext 未设置或动态更改为另一个对象。 它发生在一些包含许多不同控件的模板中。