我有以下XAML网格:
<Grid Style="{StaticResource LayoutRootStyle}" x:Name="mainGrid">
<Grid.Resources>
<Storyboard x:Name="FadeOut">
<DoubleAnimation Duration="3" To="0.0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="gridBackgroundImageBrush" d:IsOptimized="True"/>
</Storyboard>
<Storyboard x:Name="FadeIn">
<DoubleAnimation Duration="3" To="0.35" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="gridBackgroundImageBrush" d:IsOptimized="True"/>
</Storyboard>
</Grid.Resources>
<Grid.Background>
<ImageBrush x:Name="gridBackgroundImageBrush" ImageSource="{Binding BackgroundImage}" Opacity="0.35">
</ImageBrush>
</Grid.Background>
我想以编程方式启动“FadeOut”动画并从ImageBrush更改Image,然后启动“FadeIn”动画,如下所示:
private void t_Tick(object sender, object e)
{
try
{
FadeOut.Begin();
this.DefaultViewModel["BackgroundImage"] = BackgroundImage;
FadeIn.Begin();
}
catch { }
}
然而,图像在没有任何动画的情况下发生变化。我想问题是关于我如何访问ImageBrush的“Opacity”属性。我尝试了以下语法 TargetProperty属性:
(Control.Background).(ImageBrush.Opacity)
正如msdn在此处所示:http://msdn.microsoft.com/en-us/library/windows/apps/windows.ui.xaml.media.animation.storyboard.settargetproperty.aspx但它似乎不起作用。有人可以帮我解决这个问题吗?
答案 0 :(得分:2)
解决方案是创建一个图像控件,而不是使用ImageBrush绘制图像,然后定义淡入淡出的视觉状态:
<Grid Style="{StaticResource LayoutRootStyle}" x:Name="mainGrid">
<Image Grid.RowSpan="2" x:Name="gridBackgroundImageBrush" Source="{Binding BackgroundImage}" />
</Grid>
<VisualStateGroup x:Name="FadeStates">
<VisualState x:Name="FadeOutState">
<Storyboard>
<DoubleAnimation Duration="{Binding fadeDuration}" From="0.5" To="0.0" x:Name="fadeOutAnimation"
Storyboard.TargetProperty="Opacity"
Storyboard.TargetName="gridBackgroundImageBrush" />
</Storyboard>
</VisualState>
<VisualState x:Name="FadeInState">
<Storyboard>
<DoubleAnimation Duration="{Binding fadeDuration}" From="0.0" To="0.5" x:Name="fadeInAnimation"
Storyboard.TargetProperty="Opacity"
Storyboard.TargetName="gridBackgroundImageBrush" />
</Storyboard>
</VisualState>
</VisualStateGroup>