Xamarin 使用 Skiasharp 形成虚线圆

Question

我们如何使用 Skia Sharp 在 xamarin 表单中创建一个虚线圆圈，我尝试了很多，但我无法实现，有人可以帮我解决这个问题。

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

        canvas.Clear();

        SKPaint paint = new SKPaint
        {
            Style = SKPaintStyle.Stroke,
            Color = Color.Red.ToSKColor(),
            StrokeWidth = 10
        };
        canvas.DrawCircle(info.Width / 3, info.Height / 2, 100, paint);

Answer 1

你很接近。你只需要了解你在做什么。您是否正确设置了页面的构造函数？你必须

1. 创建一个 SKCanvasView 实例并将其添加到页面的内容中。
2. 因此，假设您的类或页面的名称是 SimpleCirclePage.cs，您需要在其中添加它以及其他项目。
3. 向 SKCanvasView 实例的 PaintSurface 事件添加事件处理程序。

构造函数

public SimpleCirclePage()
{
        SKCanvasView canvasView = new SKCanvasView();
        canvasView.PaintSurface += OnCanvasViewPaintSurface;
        Content = canvasView;
}

事件处理程序

void OnCanvasViewPaintSurface(object sender, SKPaintSurfaceEventArgs args)
{
        SKImageInfo info = args.Info;
        SKSurface surface = args.Surface;
        SKCanvas canvas = surface.Canvas;

        canvas.Clear();

        // Creating the Outline of the circle with Black
        SKPaint paint = new SKPaint
        {
                Style = SKPaintStyle.Stroke,
                Color = Color.Black.ToSKColor(),
                StrokeWidth = 22
        };
        canvas.DrawCircle(info.Width / 2, info.Height / 2, 100, paint);

        // Filling the circle with red
        paint.Style = SKPaintStyle.Fill;
        paint.Color = SKColors.Red;
        canvas.DrawCircle(info.Width / 2, info.Height / 2, 100, paint);
}