从网格中心展开动画

Question

我正在制作一个应用程序，当它打开时它会扩展。但它是从网格的一边扩展的，但我想让它从中心扩展。以下是xaml代码

<Window.Resources>
<Storyboard x:Key="ExpandingAnimation">
<DoubleAnimationUsingKeyFrames Storyboard.TargetName="ExpandingGrid" Storyboard.TargetProperty="(FrameworkElement.Height)">
<EasingDoubleKeyFrame KeyTime="00:00:00" Value="0"></EasingDoubleKeyFrame>
<EasingDoubleKeyFrame KeyTime="00:00:01" Value="0"></EasingDoubleKeyFrame>
<EasingDoubleKeyFrame KeyTime="00:00:03" Value="222"></EasingDoubleKeyFrame>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</Window.Resources>

<Grid x:Name="ExpandingGrid"> </Grid>

这是c#代码

public MainWindow()
{
InitializeComponent();
Storyboard ExpandingAnime = (Storyboard)TryFindResource("ExpandingAnimation");
ExpandingAnime.Begin();
}

下面是一个示例。

Answer 1

您可以使用ScaleTransform并动画其ScaleX和ScaleY属性:

<Storyboard x:Key="ExpandingAnimation">
<Storyboard>
<DoubleAnimation
Storyboard.TargetName="MyScaleTransform"
Storyboard.TargetProperty="(ScaleTransform.ScaleX)"
From="0" To ="1" Duration="0:0:3"/>
<DoubleAnimation
Storyboard.TargetName="MyScaleTransform"
Storyboard.TargetProperty="(ScaleTransform.ScaleY)"
From="0" To ="1" Duration="0:0:3"/>
</Storyboard>
</Storyboard>
...
<Grid x:Name="ExpandingGrid"
RenderTransformOrigin="0.5,0.5"
Height="222">
<Grid.RenderTransform>
<ScaleTransform x:Name="MyScaleTransform" ScaleX="0" ScaleY ="0" />
</Grid.RenderTransform>
</Grid>