WPF XAML动画实现窗体加载时的渐变显示效果,其中动画的故事面板目标属性(Storyboard.TargetProperty) 的值为 OpacityMask.(GradientBrush.GradientStops)[2].Offset ,想知道这样的写法是什么含义?为什么需要这样写,而不是 OpacityMask.GradientBrush.GradientStops[2].Offset ?有没有相关资料介绍出处提供?期望各位的赐教,谢谢!
网上摘录的一段代码
<Grid.Triggers>
<EventTrigger RoutedEvent="Loaded">
<EventTrigger.Actions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation From="1" To="0" Duration="0:0:1.5" Storyboard.TargetProperty="OpacityMask.(GradientBrush.GradientStops)[1].Offset"/>
<DoubleAnimation From="1" To="0" Duration="0:0:1" BeginTime="0:0:0.5" Storyboard.TargetProperty="OpacityMask.(GradientBrush.GradientStops)[2].Offset"/>
<ColorAnimation To="#FF000000" Duration="0" Storyboard.TargetProperty="OpacityMask.(GradientBrush.GradientStops)[2].Color"/>
</Storyboard>
</BeginStoryboard>
</EventTrigger.Actions>
</EventTrigger>
</Grid.Triggers>