WPF 控件變色

1.控件按時間灰色

<!--改變控件Fill 屬性值-->
<Ellipse x:Name="spot1" StrokeThickness="1" Width="10" Height="10" Margin="3">
   <Ellipse.Triggers>
         <EventTrigger RoutedEvent="UserControl.Loaded">
             <BeginStoryboard>
                 <Storyboard RepeatBehavior="Forever" Duration="0:0:04"><!-- Duration="0:0:04" 循環時間是4秒-->
                     <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="spot1" Storyboard.TargetProperty="Fill.GradientStops[0].Color">
                         <DiscreteColorKeyFrame KeyTime="0:0:0" Value="Red"/>
                         <DiscreteColorKeyFrame KeyTime="0:0:1" Value="Gray"/>
                         <DiscreteColorKeyFrame KeyTime="0:0:2" Value="Gray"/>
                         <DiscreteColorKeyFrame KeyTime="0:0:3" Value="Gray"/>
                     </ColorAnimationUsingKeyFrames>
                 </Storyboard>
             </BeginStoryboard>
         </EventTrigger>
     </Ellipse.Triggers>
     <Ellipse.Fill>
         <RadialGradientBrush>
             <GradientStop Color="Red" />
         </RadialGradientBrush>
     </Ellipse.Fill>
 </Ellipse>

<!--改變控件Opacity 屬性值-->
  <DoubleAnimation BeginTime="0" Storyboard.TargetName="ellipse" Storyboard.TargetProperty="(UIElement.Opacity)" From="1" To="0" Duration="00:00:01" />
  
   <!--改變控件Visibility屬性值-->
   <ObjectAnimationUsingKeyFrames BeginTime="0" FillBehavior="HoldEnd" Storyboard.TargetName="ellipse" Storyboard.TargetProperty="(UIElement.Visibility)" Duration="00:00:02">
        <DiscreteObjectKeyFrame KeyTime="0" Value="{x:Static Visibility.Visible}"/>
        <DiscreteObjectKeyFrame KeyTime="0:0:1" Value="{x:Static Visibility.Hidden}"/>
    </ObjectAnimationUsingKeyFrames>