用波浪动画填充椭圆

Question

我已经在Windows Phone 8.1 Silverlight App和UWP中创建了一个椭圆,我想用动画波填充它,为此,我正在遵循这个解决方案

但它适用于WPF,所以我无法使用像"Visual Brush"这样的控件.

我想用类似于此的波填充椭圆(忽略图像中的50%) -

这是我的eliipse

<Ellipse Name="WaveEllipse" Grid.Column="1" Grid.Row="0" VerticalAlignment="Top"
         Stroke="{StaticResource PhoneAccentBrush}"
         StrokeThickness="4"
         Width="225"
         Height="225">
</Ellipse>

视觉刷上的任何替代品？主要是我想在Windows Phone 8.1 Silverlight中实现它,但是如果它在WP平台上不可用,我将切换到UWP

Answer 1

在给你代码之前,看看下面这个动画gif,试着理解如何创建这个动画.

有道理,对吧？我们需要做的就是创建一个这样的形状,为其偏移X(无限)和Y(水位)设置动画,最后用椭圆剪切它.

首先,您需要使用Adobe Illustrator或类似工具来创建此形状.在AI中,有一个Zig Zag效果(见下面的截图),这是完美的.你只需要确保起点与结束点的位置相同,所以当你重复动画时,它会觉得它永远不会结束.

UWP中目前缺少的是能够剪切UIElement非矩形形状,因此我们必须将其导出为png(否则我们将其导出为svg并用于Path显示它).

同样出于同样的原因,剪辑部分需要大量的工作.就像Je​​t Chopper的答案一样,那就是大量的代码surfaceBrush!更不用说您还需要手动处理设备丢失和应用程序生命周期.

值得庆幸的是,在创建者更新(即15063)中,有一个新的API被称为通过图像uri LoadedImageSurface创建一个CompositionSurfaceBrush带有几行代码的UI.在我下面的代码示例中,您将看到我使用它,这意味着,如果您想支持旧版本的Windows 10,则需要将其替换为Jet的答案中的内容.

码

我们的想法是创建一个UserControl,它调用WaveProgressControl封装所有动画逻辑并公开一个Percent控制水位的依赖属性.

该WaveProgressControl控制- XAML

<UserControl x:Class="WaveProgressControlRepo.WaveProgressControl"
             Height="160"
             Width="160">

    <Grid x:Name="Root">
        <Ellipse x:Name="ClippedImageContainer"
                 Fill="White"
                 Margin="6" />
        <Ellipse x:Name="CircleBorder"
                 Stroke="#FF0289CD"
                 StrokeThickness="3" />
        <TextBlock Foreground="#FF0289CD"
                   FontSize="36"
                   FontWeight="SemiBold"
                   TextAlignment="Right"
                   VerticalAlignment="Center"
                   Width="83"
                   Margin="0,0,12,0">
            <Run Text="{x:Bind Percent, Mode=OneWay}" />
            <Run Text="%"
                 FontSize="22" />
        </TextBlock>
    </Grid>
</UserControl>

该WaveProgressControl控制-代码隐藏

private readonly Compositor _compositor;
private readonly CompositionPropertySet _percentPropertySet;

public WaveProgressControl()
{
    InitializeComponent();

    _compositor = Window.Current.Compositor;

    _percentPropertySet = _compositor.CreatePropertySet();
    _percentPropertySet.InsertScalar("Value", 0.0f);

    Loaded += OnLoaded;
}

public double Percent
{
    get => (double)GetValue(PercentProperty);
    set => SetValue(PercentProperty, value);
}
public static readonly DependencyProperty PercentProperty =
    DependencyProperty.Register("Percent", typeof(double), typeof(WaveProgressControl),
        new PropertyMetadata(0.0d, (s, e) =>
        {
            var self = (WaveProgressControl)s;
            var propertySet = self._percentPropertySet;
            propertySet.InsertScalar("Value", Convert.ToSingle(e.NewValue) / 100);
        }));

private void OnLoaded(object sender, RoutedEventArgs e)
{
    CompositionSurfaceBrush imageSurfaceBrush;

    SetupClippedWaveImage();
    SetupEndlessWaveAnimationOnXAxis();
    SetupExpressionAnimationOnYAxisBasedOnPercentValue();

    void SetupClippedWaveImage()
    {
        // Note LoadedImageSurface is only available in 15063 onward.
        var imageSurface = LoadedImageSurface.StartLoadFromUri(new Uri(BaseUri, "/Assets/wave.png"));
        imageSurfaceBrush = _compositor.CreateSurfaceBrush(imageSurface);
        imageSurfaceBrush.Stretch = CompositionStretch.None;
        imageSurfaceBrush.Offset = new Vector2(120, 248);

        var maskBrush = _compositor.CreateMaskBrush();
        var maskSurfaceBrush = ClippedImageContainer.GetAlphaMask(); // CompositionSurfaceBrush
        maskBrush.Mask = maskSurfaceBrush;
        maskBrush.Source = imageSurfaceBrush;

        var imageVisual = _compositor.CreateSpriteVisual();
        imageVisual.RelativeSizeAdjustment = Vector2.One;
        ElementCompositionPreview.SetElementChildVisual(ClippedImageContainer, imageVisual);

        imageVisual.Brush = maskBrush;
    }

    void SetupEndlessWaveAnimationOnXAxis()
    {
        var waveOffsetXAnimation = _compositor.CreateScalarKeyFrameAnimation();
        waveOffsetXAnimation.InsertKeyFrame(1.0f, -80.0f, _compositor.CreateLinearEasingFunction());
        waveOffsetXAnimation.Duration = TimeSpan.FromSeconds(1);
        waveOffsetXAnimation.IterationBehavior = AnimationIterationBehavior.Forever;
        imageSurfaceBrush.StartAnimation("Offset.X", waveOffsetXAnimation);
    }

    void SetupExpressionAnimationOnYAxisBasedOnPercentValue()
    {
        var waveOffsetYExpressionAnimation = _compositor.CreateExpressionAnimation("Lerp(248.0f, 120.0f, Percent.Value)");
        waveOffsetYExpressionAnimation.SetReferenceParameter("Percent", _percentPropertySet);
        imageSurfaceBrush.StartAnimation("Offset.Y", waveOffsetYExpressionAnimation);
    }
}

该 MainPage

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <Grid.RowDefinitions>
        <RowDefinition />
        <RowDefinition Height="Auto" />
    </Grid.RowDefinitions>

    <local:WaveProgressControl x:Name="WaveProgressControl" />

    <Slider Grid.Row="1"
            Margin="24"
            Value="{x:Bind WaveProgressControl.Percent, Mode=TwoWay}" />
</Grid>

我已将所有内容都放入此示例项目中,下面是一个现场演示.请享用!:)

Answer 2

这是UWP样本.您可以根据需要进行调整:

<Canvas>
    <Ellipse x:Name="Ellipse" Width="256" Height="256" Fill="DarkViolet" Stroke="DeepSkyBlue" StrokeThickness="8"/>
    <Border x:Name="VisualBorder" Opacity="0.5"/>
</Canvas>

和代码背后:

    private async void CreateVisuals()
    {
        var compositor = ElementCompositionPreview.GetElementVisual(this).Compositor;

        var bitmap = await CanvasBitmap.LoadAsync(CanvasDevice.GetSharedDevice(),
            new Uri("ms-appx:///Assets/Wave-PNG-Transparent-Picture.png"));

        var drawingSurface =
            CanvasComposition.CreateCompositionGraphicsDevice(compositor, CanvasDevice.GetSharedDevice())
                .CreateDrawingSurface(bitmap.Size,
                    DirectXPixelFormat.B8G8R8A8UIntNormalized, DirectXAlphaMode.Premultiplied);
        using (var ds = CanvasComposition.CreateDrawingSession(drawingSurface))
        {
            ds.Clear(Colors.Transparent);
            ds.DrawImage(bitmap);
        }

        var surfaceBrush = compositor.CreateSurfaceBrush(drawingSurface);
        surfaceBrush.Stretch = CompositionStretch.None;

        var maskedBrush = compositor.CreateMaskBrush();
        maskedBrush.Mask = Ellipse.GetAlphaMask();
        maskedBrush.Source = surfaceBrush;

        var sprite = compositor.CreateSpriteVisual();
        sprite.Size = new Vector2((float)Ellipse.Width, (float)Ellipse.Height);
        sprite.Brush = maskedBrush;
        sprite.CenterPoint = new Vector3(sprite.Size / 2, 0);
        sprite.Scale = new Vector3(0.9f);

        ElementCompositionPreview.SetElementChildVisual(VisualBorder, sprite);

        var offsetAnimation = compositor.CreateScalarKeyFrameAnimation();
        offsetAnimation.InsertKeyFrame(0, 0);
        offsetAnimation.InsertKeyFrame(1, 256, compositor.CreateLinearEasingFunction());
        offsetAnimation.Duration = TimeSpan.FromMilliseconds(1000);
        offsetAnimation.IterationBehavior = AnimationIterationBehavior.Forever;

        surfaceBrush.StartAnimation("Offset.X", offsetAnimation);
    }
}

这是它的样子: