背景 ImageBrush 的 XAML 故事板 [英] XAML Storyboard for Background ImageBrush

问题描述

我有以下 XAML 网格:

I have the following XAML Grid:

 <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淡出"动画并从 ImageBrush 更改图像，然后启动淡入"动画，如下所示:

I want to programmatically start the "FadeOut" animation and change the Image from ImageBrush, then start the "FadeIn" animation, like this:

private void t_Tick(object sender, object e)
    {
        try
        {
            FadeOut.Begin();
            this.DefaultViewModel["BackgroundImage"] = BackgroundImage;
            FadeIn.Begin();
        }
        catch { }
    }

但是图像在没有任何动画的情况下发生变化.我想问题在于我如何访问 ImageBrush 的Opacity"属性.我尝试了以下语法TargetProperty 属性:

However the image is changing without any animation. I guess the problem is about how I'm accessing the "Opacity" property of the ImageBrush. I tried the following syntax for the TargetProperty attribute:

(Control.Background).(ImageBrush.Opacity)

如 msdn 所示:http://msdn.microsoft.com/en-us/library/windows/apps/windows.ui.xaml.media.animation.storyboard.settargetproperty.aspx 但它似乎没有上班.有人可以帮我解决这个问题吗?

as msdn shows here: http://msdn.microsoft.com/en-us/library/windows/apps/windows.ui.xaml.media.animation.storyboard.settargetproperty.aspx but it doesn't seem to work. Can someone help me with this problem?

推荐答案

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:

The solution was to create an image control rather than drawing the image with ImageBrush and then defining visual states for fading:

<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>

这篇关于背景 ImageBrush 的 XAML 故事板的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！