在 XAML 中投射 WPF 属性

Question

I'm wondering if it's possible to cast properties in WPF?

I've this code

<Window.Triggers>
    <EventTrigger RoutedEvent="Window.Loaded">
        <BeginStoryboard>
            <Storyboard>
                <DoubleAnimation Storyboard.TargetProperty="(Window.Opacity)" From="0.0" To="0.92" Duration="0:0:0.15" AutoReverse="False" />
            </Storyboard>
        </BeginStoryboard>
    </EventTrigger>
</Window.Triggers>

and i want to modify my window background opacity but i need to cast Window.Background to SolidColorBrush that's why i'm wondering if it's possible and if yes how to do it (and if not if you have a good way to do it)

Thanks for your help:)

Answer 1

This will work, as a replacement for the DoubleAnimation in your question. You were very close. There's usually no need for type casting in XAML. It's "duck typed". However, lankitha's excellent answer illustrates how it's done in a property path: (Window.Background).(SolidColorBrush.Color) . Or (Window.Background).(SolidColorBrush.Opacity) here. But that's not necessary in this case.

<DoubleAnimation
    Storyboard.TargetProperty="Background.Opacity"
    From="0.0" 
    To="0.92" 
    Duration="0:0:0.15" 
    AutoReverse="False" 
    />

If you want to make your window to be actually transparent by making the background transparent, you'll need the following as well on the Window element itself:

AllowsTransparency="True"
WindowStyle="None"

Answer 2

Please try ColorAnimation functionality. Usually, #00000000 stands for transparent a hex colour with additional two zeros for the opacity at the start, in the format of aRGB . Set the colour of the window to the colour mentioned above. and in the colour animation set it to the desired colour.

try this

<EventTrigger RoutedEvent="Window.Loaded">
            <BeginStoryboard>
                <Storyboard>
                    <ColorAnimation To="#FF000000" 
                                    Storyboard.TargetProperty="(Window.Background).(SolidColorBrush.Color)" 
                                    FillBehavior="Stop" 
                                    Duration="0:0:0.15"/>
                </Storyboard>
            </BeginStoryboard>
        </EventTrigger>

Hope this helps.