WPF实现的加载动画

2020-09-03 09:43:30

xaml代码 

  <Grid x:Name="LayoutRoot" Background="Transparent"  ToolTip="Searching...."  HorizontalAlignment="Center"  VerticalAlignment="Center">   <Canvas RenderTransformOrigin="0.5,0.5"   HorizontalAlignment="Center"   VerticalAlignment="Center" Width="120"   Height="120" Loaded="HandleLoaded"   Unloaded="HandleUnloaded" >    <Ellipse x:Name="C0" Width="20" Height="20"     Canvas.Left="0"     Canvas.Top="0" Stretch="Fill"     Fill="#bbc3de" Opacity="1.0"/>    <Ellipse x:Name="C1" Width="20" Height="20"     Canvas.Left="0"     Canvas.Top="0" Stretch="Fill"     Fill="#bbc3de" Opacity="0.9"/>    <Ellipse x:Name="C2" Width="20" Height="20"     Canvas.Left="0"     Canvas.Top="0" Stretch="Fill"     Fill="#bbc3de" Opacity="0.8"/>    <Ellipse x:Name="C3" Width="20" Height="20"     Canvas.Left="0"     Canvas.Top="0" Stretch="Fill"     Fill="#bbc3de" Opacity="0.7"/>    <Ellipse x:Name="C4" Width="20" Height="20"     Canvas.Left="0"     Canvas.Top="0" Stretch="Fill"     Fill="#bbc3de" Opacity="0.6"/>    <Ellipse x:Name="C5" Width="20" Height="20"     Canvas.Left="0"     Canvas.Top="0" Stretch="Fill"     Fill="#bbc3de" Opacity="0.5"/>    <Ellipse x:Name="C6" Width="20" Height="20"     Canvas.Left="0"     Canvas.Top="0" Stretch="Fill"     Fill="#bbc3de" Opacity="0.4"/>    <Ellipse x:Name="C7" Width="20" Height="20"     Canvas.Left="0"     Canvas.Top="0" Stretch="Fill"     Fill="#bbc3de" Opacity="0.3"/>    <Ellipse x:Name="C8" Width="20" Height="20"     Canvas.Left="0"     Canvas.Top="0" Stretch="Fill"     Fill="#bbc3de" Opacity="0.2"/>    <Canvas.RenderTransform>     <RotateTransform x:Name="SpinnerRotate"     Angle="0" />    </Canvas.RenderTransform>   </Canvas>  </Grid>

　　后台代码

 public partial class UserControlLoad : UserControl {  public UserControlLoad()  {   InitializeComponent();   animationTimer = new DispatcherTimer(DispatcherPriority.ContextIdle, Dispatcher);   animationTimer.Interval = new TimeSpan(0, 0, 0, 0, 75);   Start();  }  private readonly DispatcherTimer animationTimer;  #region Private Methods  public void Start()  {   Mouse.OverrideCursor = Cursors.Wait;   animationTimer.Tick += HandleAnimationTick;   animationTimer.Start();  }  private void Stop()  {   animationTimer.Stop();   Mouse.OverrideCursor = Cursors.Arrow;   animationTimer.Tick -= HandleAnimationTick;  }  private void HandleAnimationTick(object sender, EventArgs e)  {   SpinnerRotate.Angle = (SpinnerRotate.Angle + 36) % 360;  }  private void HandleLoaded(object sender, RoutedEventArgs e)  {   const double offset = Math.PI;   const double step = Math.PI * 2 / 10.0;   SetPosition(C0, offset, 0.0, step);   SetPosition(C1, offset, 1.0, step);   SetPosition(C2, offset, 2.0, step);   SetPosition(C3, offset, 3.0, step);   SetPosition(C4, offset, 4.0, step);   SetPosition(C5, offset, 5.0, step);   SetPosition(C6, offset, 6.0, step);   SetPosition(C7, offset, 7.0, step);   SetPosition(C8, offset, 8.0, step);  }  private void SetPosition(Ellipse ellipse, double offset,   double posOffSet, double step)  {   ellipse.SetValue(Canvas.LeftProperty, 50.0    + Math.Sin(offset + posOffSet * step) * 50.0);   ellipse.SetValue(Canvas.TopProperty, 50    + Math.Cos(offset + posOffSet * step) * 50.0);  }  private void HandleUnloaded(object sender, RoutedEventArgs e)  {   Stop();  }  private void HandleVisibleChanged(object sender,   DependencyPropertyChangedEventArgs e)  {   bool isVisible = (bool)e.NewValue;   if (isVisible)    Start();   else    Stop();  }