如何将wpf弹出窗口中的IsOpen属性设置为True？

Question

我有这种 wpf 风格：

<Style x:Key="RequiredControlTemplate">
    <Style.Setters>
        <Setter Property="Validation.ErrorTemplate">
            <Setter.Value>
                <ControlTemplate>
                    <StackPanel>
                        <Popup IsOpen="{Binding ElementName=Adorner, Path=IsMouseOver}">
                            <TextBlock Text="{Binding ElementName=Adorner, Path=AdornedElement.(Validation.Errors)[0].ErrorContent}" />
                        </Popup>
                        <Border Grid.Column="1" BorderBrush="Red" BorderThickness="1" HorizontalAlignment="Stretch">
                            <AdornedElementPlaceholder Name="Adorner"/>
                        </Border>
                    </StackPanel>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style.Setters>
</Style>

我希望如果鼠标位于 Adorner 上，则 Popup 打开，但 IsOpen="{Binding ElementName=Adorner, Path=IsMouseOver} 不起作用...

Answer 1

我对你的风格做了一些改变。
添加了几个故事板来玩弹出打开...并触发装饰元素上的故事板

<Style x:Key="RequiredControlTemplate">
            <Style.Setters>
                <Setter Property="Validation.ErrorTemplate">
                    <Setter.Value>
                        <ControlTemplate>
                            <StackPanel>
                                <StackPanel.Resources>
                                    <Storyboard x:Key="OnMouseEnter1">
                                        <BooleanAimationUsingKeyFrames Storyboard.TargetProperty="(Popup.IsOpen)" Storyboard.TargetName="popup">
                                            <DiscreteBooleanKeyFrame KeyTime="0" Value="True"/>
                                        </BooleanAnimationUsingKeyFrames>
                                    </Storyboard>
                                    <Storyboard x:Key="OnMouseLeave1">
                                        <BooleanAnimationUsingKeyFrames Storyboard.TargetProperty="(Popup.IsOpen)" Storyboard.TargetName="popup">
                                            <DiscreteBooleanKeyFrame KeyTime="0" Value="True"/>
                                            <DiscreteBooleanKeyFrame KeyTime="0:0:0.1" Value="False"/>
                                        </BooleanAnimationUsingKeyFrames>
                                    </Storyboard>
                                </StackPanel.Resources>
                                <Popup  Name="popup">
                                    <TextBlock Text="{Binding ElementName=Adorner, Path=AdornedElement.(Validation.Errors)[0].ErrorContent}" />
                                </Popup>
                                <Border Grid.Column="1" BorderBrush="Red" BorderThickness="1" HorizontalAlignment="Stretch">
                                    <AdornedElementPlaceholder Name="Adorner">
                                        <AdornedElementPlaceholder.Triggers>
                                            <EventTrigger RoutedEvent="Mouse.MouseLeave" SourceName="Adorner">
                                                <BeginStoryboard x:Name="OnMouseLeave1_BeginStoryboard" Storyboard="{StaticResource OnMouseLeave1}"/>
                                            </EventTrigger>
                                            <EventTrigger RoutedEvent="Mouse.MouseEnter" SourceName="Adorner">
                                                <BeginStoryboard Storyboard="{StaticResource OnMouseEnter1}"/>
                                            </EventTrigger>
                                        </AdornedElementPlaceholder.Triggers>
                                    </AdornedElementPlaceholder>
                                </Border>
                            </StackPanel>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style.Setters>
        </Style>

Answer 2

将 Mode=OneWay 添加到绑定中。 IsOpen 默认为 TwoWay，只读属性不允许 TwoWay 绑定。

Answer 3

如果您不遵循 MVVM 模式，您可以在 xaml 中指定 x:code ，您可以在其中处理 MouseOver 事件，并使用 EventSetter 附加它。