Skiasharp 文本渲染脱离画布

Question

我正在使用skiasharp 和xamarin 表单创建自定义控件。我遇到的情况是，当我尝试在画布的左上角绘制文本时，我必须偏移 y 坐标才能使文本在画布中呈现。我希望文本的 x y 坐标与矩形的 x y 坐标处于相同的位置。我错过了什么？

使用 Skiasharp.View.Forms - v1.68.1 off nuget

谢谢！

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

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

  canvas.Clear();
  canvas.Save();

  using var paint = new SKPaint {IsAntialias = true, Color = Color.Black.ToSKColor(), Style = SKPaintStyle.Stroke};

  canvas.DrawRect(0, 0, info.Width, info.Height, paint);

  canvas.DrawText("Off screen", 0, 0, paint);
  canvas.DrawText("On screen", 0, 10, paint);

  canvas.Restore();
}

Answer 1

你可以设置y坐标为SKPaint.FontSpacing，这是推荐的行距。

 canvas.DrawText("SKCanvasView Height and Width:", 0, paint.FontSpacing, paint);

参考https://github.com/xamarin/xamarin-forms-samples/blob/f7cc661331b5db605e64e7efe83ef2b9fc644afb/SkiaSharpForms/Demos/Demos/SkiaSharpFormsDemos/Basics/SurfaceSizePage.cs#L38