.net c#动态生成随机饼状图报表

如果项目为了安全,不引入第三方dll,则可以使用Graphics自己画图,的情况下,
首先建一个实体:

        public class StatCount
        {
            /// <summary>
            /// 名称
            /// </summary>
            public string name { get; set; }
            /// <summary>
            /// 数量
            /// </summary>
            public int count { get; set; }
        }

从数据库中读取实体集合:

        public static Image Draw(List<StatCount> list, Image imgfont, int width = 500, int height = 500)
        {
            System.Drawing.Bitmap image = new System.Drawing.Bitmap(width, height);
            //创建Graphics类对象,用来画饼状图
            Graphics g = Graphics.FromImage(image);
            Pen p = new Pen(new SolidBrush(Color.Blue));
            Point p1 = new Point(0, 0);
            Size s = new Size(width, height);
            Rectangle trct = new Rectangle(p1, s);
            g.FillEllipse(new SolidBrush(Color.Red), trct);
            Font font = new Font("宋体", 10, FontStyle.Regular);
            int total = list.Sum((w) => { return w.count; });

            //写文字
            Graphics gfont = Graphics.FromImage(imgfont);
            int fontspan = 15;

            for (int i = 0; i < list.Count; i++)
            {
                //画大饼
                Color color = ColorIndex(i);
                float f = float.Parse(list[i].count.ToString()) / float.Parse(total.ToString());
                //写文字
                fontspan = fontspan + 15;
                //绘制小矩形
                gfont.FillRectangle(new SolidBrush(color), 0, fontspan, 20, 10);
                //写百分比文字
                gfont.DrawString(list[i].name + " " + FormatCentStr(total, list[i].count), font, new SolidBrush(Color.Blue), 30, fontspan);
            }
            return image;
        }

调用并测试画饼状图.

        public void DrawPie()
        {
            //年某商品走势
            List<GraPie.StatCount> list = new List<GraPie.StatCount>();
            int count = GraPie.Random().Next(2, 6);
            for (int i = 1; i <= count; i++)
            {
                list.Add(new GraPie.StatCount() { name = i.ToString() + "月", count = GraPie.Random(1, 1000) });
            }
            Image imgfont = new System.Drawing.Bitmap(zpictwo.Width, zpictwo.Height);
            zpic.BackgroundImage = GraPie.Draw(list, imgfont, zpic.Width, zpic.Height);
            zpictwo.BackgroundImage = imgfont;
        }

实现效果如下: