[FAQ] drawing concentric circles

Q:

Use GDI + to draw an image such

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);       }   }}

Parameter information:

G: drawing surface
X, Y: Drawing position
RADIUS: concentric circle radius
Angle: offset angle (based on the innermost concentric circle)
Layer: Number of concentric circles

Test cases:

Renderellipses (E. Graphics, 220,220, 50, 60, 4 );