利用wpf写一个loading动画

以下是一个简单的WPF Loading动画的代码：

<Window x:Class="LoadingAnimationWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="LoadingAnimationWindow" Height="150" Width="350">
    <Grid>
        <Ellipse x:Name="Ellipse1" Width="30" Height="30" Fill="LightBlue">
            <Ellipse.RenderTransform>
                <TranslateTransform X="0" Y="0"/>
            </Ellipse.RenderTransform>
            <Ellipse.Triggers>
                <EventTrigger RoutedEvent="Loaded">
                    <BeginStoryboard>
                        <Storyboard>
                            <DoubleAnimation Storyboard.TargetProperty="(Ellipse.RenderTransform).(TranslateTransform.X)"
                                             From="0" To="200" Duration="0:0:1" RepeatBehavior="Forever"/>
                        </Storyboard>
                    </BeginStoryboard>
                </EventTrigger>
            </Ellipse.Triggers>
        </Ellipse>
        <Ellipse x:Name="Ellipse2" Width="30" Height="30" Fill="LightBlue">
            <Ellipse.RenderTransform>
                <TranslateTransform X="0" Y="0"/>
            </Ellipse.RenderTransform>
            <Ellipse.Triggers>
                <EventTrigger RoutedEvent="Loaded">
                    <BeginStoryboard>
                        <Storyboard>
                            <DoubleAnimation Storyboard.TargetProperty="(Ellipse.RenderTransform).(TranslateTransform.X)"
                                             From="0" To="-200" Duration="0:0:1" RepeatBehavior="Forever"/>
                        </Storyboard>
                    </BeginStoryboard>
                </EventTrigger>
            </Ellipse.Triggers>
        </Ellipse>
    </Grid>
</Window>

这个Loading动画使用了两个椭圆（Ellipse）来表示动画，每个椭圆都有一个 `TranslateTransform` 作为其渲染变换（Render Transform），并在其 `Loaded` 事件中启动一个 `Storyboard`，使用 `DoubleAnimation` 来改变 `TranslateTransform` 的 X 坐标值，从而实现椭圆的移动。两个椭圆的移动方向相反，从而形成动画效果。