private void Canvas_SizeChanged(object sender, SizeChangedEventArgs e)
{
Center.X = e.NewSize.Width / 2;
Center.Y = e.NewSize.Height / 2;
Radius = Math.Min(e.NewSize.Width, e.NewSize.Height) / 2 - ThumbSize / 2;
Ellipse.Width = Ellipse.Height = Radius * 2;
Canvas.SetLeft(Ellipse, Center.X - Radius);
Canvas.SetTop(Ellipse, Center.Y - Radius);
Rotation = rotation;
AngleChange?.Invoke(this, Rotation / 180 * Math.PI, Rotation); //用户控件：Value改变
}
//滚轮
private void Wheel_Changed(Point p, double d)
{
Rotation += d / 100;
AngleChange?.Invoke(this, Rotation / 180 * Math.PI, Rotation); //用户控件：Value改变
}
private void Complete(Point p)
{
Rotation = Method.点角度(Center, p);
AngleChange?.Invoke(this, Rotation / 180 * Math.PI, Rotation); //用户控件：Value改变
}
