如何淡化WPF背景图片？

Question

如何淡化背景WPF图像？

我的XAML看起来像这样：

    <Grid.Background>
        <ImageBrush ImageSource="themes\backpic.png" Stretch="UniformToFill">
        </ImageBrush>
    </Grid.Background> 

我尝试过类似的事情：

 <Grid.Background>
        <ImageBrush ImageSource="pics\bl.png" Stretch="UniformToFill">
            <ImageBrush.Transform>
                <!-- some code here-->
            </ImageBrush.Transform>
        </ImageBrush>
    </Grid.Background>

Answer 1

启动ImageBrush的Opacity属性的DoubleAnimation：

<Grid>
    ...
    <Grid.Triggers>
        <EventTrigger RoutedEvent="Loaded">
            <BeginStoryboard>
                <Storyboard>
                    <DoubleAnimation
                        Storyboard.TargetProperty="Background.Opacity"
                        To="0" Duration="0:0:2"/>
                </Storyboard>
            </BeginStoryboard>
        </EventTrigger>
    </Grid.Triggers>
    ...
</Grid>