[FAQ]繪製同心圓圖形

Q：

用GDI+繪製出如的圖形

refer：http://bbs.csdn.net/topics/390546290

A：

public void RenderEllipses(Graphics g, float x, float y, float radius, float angle, int layer){    float inflateRadius = -radius / 4;    for (int i = 1; i <= layer; i++)    {        float A = angle / i;        int count = (int)Math.Round(360 / A);        for (int j = 0; j < count; j++)        {            float R = radius * i;            float rx = (float)Math.Cos(A * Math.PI / 180 * j) * R + x;            float ry = (float)Math.Sin(A * Math.PI / 180 * j) * R + y;             RectangleF bound = new RectangleF(rx, ry, radius, radius);             using (Brush brush = new SolidBrush(Color.LightGray))                g.FillEllipse(brush, bound);            using (Pen pen = new Pen(Color.Black, 1))                g.DrawEllipse(pen, bound);             bound.Inflate(inflateRadius, inflateRadius);            using (Brush brush = new SolidBrush(Color.Orange))                g.FillEllipse(brush, bound);            using (Pen pen = new Pen(Color.Black, 1))                g.DrawEllipse(pen, bound);       }   }}

參數資訊：

g         ：繪圖表面
x,y       ：繪製位置
radius：同心圓半徑
angle ：位移角度(基於最內層同心圓)
layer   ：同心圓層數

測試案例：

RenderEllipses(e.Graphics, 220, 220, 50, 60, 4);