如何使用SkiaSharp在Xamarin中创建简单动画

using SkiaSharp;
using SkiaSharp.Views.Forms;
using Xamarin.Forms;

namespace YourNamespace
{
    public class AnimationView : SKCanvasView
    {
        private float angle = 0;

        protected override void OnPaintSurface(SKPaintSurfaceEventArgs e)
        {
            base.OnPaintSurface(e);

            SKImageInfo info = e.Info;
            SKSurface surface = e.Surface;
            SKCanvas canvas = surface.Canvas;

            canvas.Clear();

            using (SKPaint paint = new SKPaint())
            {
                paint.Style = SKPaintStyle.Fill;
                paint.IsAntialias = true;

                // 创建一个渐变色
                SKColor[] colors = { SKColors.Red, SKColors.Green, SKColors.Blue };
                SKShader shader = SKShader.CreateLinearGradient(
                    new SKPoint(0, 0),
                    new SKPoint(info.Width, info.Height),
                    colors,
                    null,
                    SKShaderTileMode.Clamp);
                paint.Shader = shader;

                // 绘制一个旋转的矩形
                SKRect rect = new SKRect(0, 0, info.Width, info.Height);
                canvas.RotateDegrees(angle, info.Width / 2, info.Height / 2);
                canvas.DrawRect(rect, paint);

                // 更新角度
                angle += 1;

                // 重新绘制
                InvalidateSurface();
            }
        }
    }

    public class MainPage : ContentPage
    {
        public MainPage()
        {
            AnimationView animationView = new AnimationView();

            Content = new StackLayout
            {
                Children = { animationView }
            };
        }
    }
}