我希望能够平滑地绘制一个圆(椭圆),以便您可以在屏幕上看到它正在被绘制。
有没有可能使用DoubleAnimation来实现这一点?如果不行,有什么替代方法?
以下是我拥有的示例:
- 一个外部椭圆(黑色)
- 内部椭圆(白色)- 这是我想要动画的那个椭圆
代码:
<Ellipse Width="200" Height="200" Stroke="Black" StrokeThickness="20"/>
<Ellipse Width="190" Height="190" Stroke="White" StrokeThickness="10" Canvas.Left="5" Canvas.Top="5" x:Name="animatedEllipse">
<Ellipse.Triggers>
<EventTrigger RoutedEvent="Ellipse.Loaded">
<BeginStoryboard>
<Storyboard>
<DoubleAnimation/>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Ellipse.Triggers>
</Ellipse>
我查看了一些例子,例如:
- http://elegantcode.com/2009/08/21/a-simple-wpf-loading-animation/
- http://www.charlespetzold.com/blog/2012/03/The-Animated-Pie-Slice-in-Windows-8.html
- Ellipse Drawing WPF Animation
对于我这个初学者来说,前两个有点困惑。后一个被评为“正确答案”,但我遇到了错误:“the collection element StrokeDashArray[0] is not a dependency property”(而且我不想要虚线,尽管我按照上述文章的方法在椭圆上试了试,但仍然会出现此错误。
更新:
我使用代码得到的一个方法是这样的:
public static class ExtensionMethods
{
private static Action EmptyDelegate = delegate() { };
public static void Refresh(this UIElement uiElement)
{
uiElement.Dispatcher.Invoke(DispatcherPriority.Render, EmptyDelegate);
}
}
public partial class Page1 : Page
{
private void Page_Loaded_1(object sender, RoutedEventArgs e)
{
path = new Path();
group = new GeometryGroup();
path.Data = group;
path.Stroke = new SolidColorBrush(Colors.White);
path.StrokeThickness = 3;
canvas.Children.Add(path);
BackgroundWorker worker = new BackgroundWorker();
worker.DoWork += worker_DoWork;
worker.RunWorkerAsync();
}
void worker_DoWork(object sender, DoWorkEventArgs e)
{
int radius = 90;
for (double i = 0.0; i < 360.0; i += 1)
{
double angle = i * System.Math.PI / 180;
double x = (int)(100 + radius * System.Math.Cos(angle));
double y = (int)(100 + radius * System.Math.Sin(angle));
canvas.Dispatcher.Invoke(new Action(delegate
{
group.Children.Add(new EllipseGeometry(new Point(x, y), 5, 5));
}));
canvas.Refresh();
System.Threading.Thread.Sleep(1);
}
}