wpf - 如何延迟打开 WPF 弹出窗口？

Question

我只是想打开WPF Popup有延迟，有点像 ToolTip .

我怎样才能实现这个目标？

顺便说一下，Popup.PopupAnimation = PopupAnimation.Fade ...淡入得太快了。我想要至少半秒钟。

Answer 1

您可以通过以下方式创建要应用于弹出窗口的样式:

<Style x:Key="TooltipPopupStyle" TargetType="Popup">
    <Style.Triggers>
        <DataTrigger Binding="{Binding PlacementTarget.IsMouseOver, RelativeSource={RelativeSource Self}}" Value="True">
            <DataTrigger.EnterActions>
                <BeginStoryboard x:Name="OpenPopupStoryBoard" >
                    <Storyboard>
                        <BooleanAnimationUsingKeyFrames Storyboard.TargetProperty="IsOpen" FillBehavior="HoldEnd">
                            <DiscreteBooleanKeyFrame KeyTime="0:0:0.25" Value="True"/>
                        </BooleanAnimationUsingKeyFrames>
                    </Storyboard>
                </BeginStoryboard>
            </DataTrigger.EnterActions>
            <DataTrigger.ExitActions>
                <PauseStoryboard BeginStoryboardName="OpenPopupStoryBoard"/>
                <BeginStoryboard x:Name="ClosePopupStoryBoard">
                    <Storyboard>
                        <BooleanAnimationUsingKeyFrames Storyboard.TargetProperty="IsOpen" FillBehavior="HoldEnd">
                            <DiscreteBooleanKeyFrame KeyTime="0:0:1" Value="False"/>
                        </BooleanAnimationUsingKeyFrames>
                    </Storyboard>
                </BeginStoryboard>
            </DataTrigger.ExitActions>
        </DataTrigger>

        <Trigger Property="IsMouseOver" Value="True">
            <Trigger.EnterActions>
                <PauseStoryboard BeginStoryboardName="ClosePopupStoryBoard" />
            </Trigger.EnterActions>
            <Trigger.ExitActions>
                <PauseStoryboard BeginStoryboardName="OpenPopupStoryBoard"/>
                <ResumeStoryboard BeginStoryboardName="ClosePopupStoryBoard" />
            </Trigger.ExitActions>
        </Trigger>
    </Style.Triggers>
</Style>

然后，每当您想使用它时，您都可以编写与此类似的标记(注意 PlacementTarget 的绑定(bind)):

<TextBlock x:Name="TargetControl" Text="Hover over me!" />
<Popup PlacementTarget="{Binding ElementName=TargetControl}" Style="{StaticResource TooltipPopupStyle}">
    <Border BorderBrush="Red" BorderThickness="1" Background="White">
        <TextBlock Text="This is a Popup behaving somewhat like the tooltip!" Margin="10" />
    </Border>
</Popup>