ASP.NET输出绘制图形



protected void Page_Load(object sender, EventArgs e)
    {
        int[] data = { 100, 200, 300, 400,66,55,777,435,634,454,634,443,352,546,635,454,454,5,535, };
        //饼的颜色
        Color[] colors = { Color.Red, Color.LightCoral, Color.LightCyan, Color.LightGray, Color.LightGreen, Color.LightPink, Color.LightSeaGreen };

        //要绘制的对象
        Bitmap bm = new Bitmap(400, 400);
        Graphics g = Graphics.FromImage(bm);
        g.Clear(Color.Silver);
        g.DrawString("饼图测试", new Font("宋体", 16), Brushes.Red, new PointF(4, 4));

        float totalValue = 0;
        foreach (float i in data)
        {
            totalValue += i;
        }

        float sweepAngle = 0;//本次经过角度
        float startAngle = 0;//本次起始角度
        
        float x = 50f;//饼所在的矩形方位。
        float y = 50f;
        float width = 300;


        for(int i=0;i<data.Length;i++)
        {
            sweepAngle = data[i] / totalValue * 360;
            //
            g.FillPie(new SolidBrush(colors[i % colors.Length]), x, y, width, width, startAngle, sweepAngle);
            g.DrawPie(Pens.Indigo, x, y, width, width, startAngle, sweepAngle);
            startAngle += sweepAngle;

        }

        //图形输出方式
        bm.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Gif);

        g.Dispose();
    }