void DrawText(string text, ICanvas canvas, NGraphics.Point center, double radius, NGraphics.Font font, Xamarin.Forms.Color textColor, double middleRadian)
{
if (!string.IsNullOrWhiteSpace(text))
{
double textRadius = radius * 0.67;
NGraphics.Point centerText = new NGraphics.Point(center.X + Math.Cos(middleRadian) * textRadius, center.Y + Math.Sin(middleRadian) * textRadius);
const double width = 40;
const double height = 5;
Rect rect = new Rect(centerText.X - width / 2.0, centerText.Y, width, height);
canvas.DrawText(text, rect, font, NGraphics.TextAlignment.Center, new Pen(textColor.ToCross()), new SolidBrush(textColor.ToCross()));
}
}