在SkiaSharp画布上以Xamarin形式居中对齐圆

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

public class CircleView : SKCanvasView
{
    protected override void OnPaintSurface(SKPaintSurfaceEventArgs e)
    {
        base.OnPaintSurface(e);

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

        canvas.Clear();

        // 计算圆的半径和位置
        float radius = Math.Min(info.Width, info.Height) / 2f;
        float x = (info.Width - radius) / 2f;
        float y = (info.Height - radius) / 2f;

        // 创建画笔并绘制圆
        using (SKPaint paint = new SKPaint())
        {
            paint.Style = SKPaintStyle.Fill;
            paint.Color = SKColors.Blue;

            canvas.DrawCircle(x + radius, y + radius, radius, paint);
        }
    }
}

public class MainPage : ContentPage
{
    public MainPage()
    {
        CircleView circleView = new CircleView();

        // 设置布局参数，使视图居中对齐
        circleView.HorizontalOptions = LayoutOptions.Center;
        circleView.VerticalOptions = LayoutOptions.Center;

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