protected override HandleRef BuildWindowCore(HandleRef hwndParent)
{
var wndclass = new User32.WNDCLASSEX();
wndclass.cbSize = Marshal.SizeOf <User32.WNDCLASSEX>();
wndclass.style = 0;
wndclass.hInstance = Kernel32.GetModuleHandle(null).DangerousGetHandle();
User32.RegisterClassEx(ref wndclass);
var windowHandle = User32.CreateWindowEx((User32.WindowStylesEx)WS_EX_NOREDIRECTIONBITMAP, "static", "", User32.WindowStyles.WS_CHILD | User32.WindowStyles.WS_CLIPCHILDREN | User32.WindowStyles.WS_VISIBLE, 0, 0, (int)Width, (int)Height, hwndParent.Handle, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero);
User32.SetWindowPos(windowHandle, hwndParent.Handle, 0, 0, (int)Width, (int)Height, User32.SetWindowPosFlags.SWP_SHOWWINDOW);
ANGLE.InitializeContext((int)Width, (int)Height, true, windowHandle, User32.GetDC(windowHandle).DangerousGetHandle());
var angleInterface = GRGlInterface.CreateAngle(ANGLE.AngleGetProcAddress);
var grContext = GRContext.CreateGl(angleInterface);
var buffer = ANGLE.GetFrameBuffer();
var fbinfo = new GRGlFramebufferInfo(buffer, ANGLE.GetFramebufferFormat());
var backendRT = new GRBackendRenderTarget((int)Width, (int)Height, 4, 8, fbinfo);
var surfaceprops = new SKSurfaceProperties(SKSurfacePropsFlags.UseDeviceIndependentFonts, SKPixelGeometry.Unknown);
var surface = SKSurface.Create(grContext, backendRT, GRSurfaceOrigin.BottomLeft, SKColorType.Rgba8888, null, surfaceprops);
var canvas = surface.Canvas;
canvas.Clear(SKColor.Empty);
SKPaint paint = new SKPaint();
paint.Style = SKPaintStyle.Fill;
paint.IsAntialias = true;
paint.StrokeWidth = 4;
paint.Color = new SKColor(0xff4285f4);
SKRect rect = SKRect.Create(10, 10, 100, 160);
canvas.DrawRect(rect, paint);
SKRoundRect oval = new SKRoundRect();
oval.SetOval(rect);
oval.Offset(40, 80);
paint.Color = new SKColor(0xffdb4437);
canvas.DrawRoundRect(oval, paint);
paint.Color = new SKColor(0xff0f9d58);
canvas.DrawCircle(180, 50, 25, paint);
rect.Offset(80, 50);
paint.Color = new SKColor(0xfff4b400);
paint.Style = SKPaintStyle.Stroke;
canvas.DrawRoundRect(rect, 10, 10, paint);
canvas.Flush();
ANGLE.Swap();
return(new HandleRef(this, windowHandle));
}
