wpf - 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>

我希望如果鼠标悬停在 Adorner 上，那么 Popup 会打开，但IsOpen="{Binding ElementName=Adorner, Path=IsMouseOver}不起作用...

Answer 1

添加Mode=OneWay到绑定。IsOpenTwoWay默认情况下，只读属性不允许TwoWay绑定。

Answer 2

我对你的风格做了一些改变。添加了几个故事板以弹出打开...并在装饰元素上触发故事板

<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 3

如果你不遵循 MVVM 模式，你可以x:code在你的 xaml 中指定你可以在哪里处理 MouseOver 事件，并使用EventSetter它来附加它。