快速生成折线图及代码详解

快速生成折线图时，只需要修改代码中的以下数据：

1、Y轴刻度个数：Ycounts

2、Y轴最小刻度数：YminValue

3、横坐标：数组mouth

4、标题：strTopic

5、用户数据：数组d

6、[可选]修改背景色：代码中27行改为所需要的颜色即可

完整代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace Test11
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Paint(object sender, PaintEventArgs e)
        {
            int Ycounts = 9;//Y轴刻度个数
            int YminValue = 20;//Y轴最小值
            string[] month = new string[8] { "1至3天", "4至7天", "8至14天", "15至21天", "22至28天", "29至39天", "36至42天", "42天以后" };
            float[] d = new float[8] { 36, 35, 33.5F, 31.5F, 29, 27, 26, 21 };
            //画图初始化
            Bitmap bMap = new Bitmap(500, 500);
            Graphics gph = Graphics.FromImage(bMap);
            gph.Clear(Color.White);
            PointF cPt = new PointF(40, 420);//中心点
            PointF[] xPt = new PointF[3] { new PointF(cPt.Y + 15, cPt.Y), new PointF(cPt.Y, cPt.Y - 8), new PointF(cPt.Y, cPt.Y + 8) };//X轴三角形
            PointF[] yPt = new PointF[3] { new PointF(cPt.X, cPt.X - 15), new PointF(cPt.X - 8, cPt.X), new PointF(cPt.X + 8, cPt.X) };//Y轴三角形
            string strTopic = "畜禽温度时刻图表";
            gph.DrawString(strTopic, new Font("宋体", 14), Brushes.Black, new PointF((cPt.Y-strTopic.Length*14)/2, cPt.X*2f/3));//图表标题,居中对齐
            //画X轴
            gph.DrawLine(Pens.Black, cPt.X, cPt.Y, cPt.Y, cPt.Y);
            gph.DrawPolygon(Pens.Black, xPt);
            gph.FillPolygon(new SolidBrush(Color.Black), xPt);
            gph.DrawString("天数", new Font("宋体", 12), Brushes.Black, new PointF(cPt.Y + 12, cPt.Y + 12));//12为字体大小
            //画Y轴
            gph.DrawLine(Pens.Black, cPt.X, cPt.Y, cPt.X, cPt.X);
            gph.DrawPolygon(Pens.Black, yPt);
            gph.FillPolygon(new SolidBrush(Color.Black), yPt);
            gph.DrawString("单位(摄氏度)", new Font("宋体", 12), Brushes.Black, new PointF(0, 6));//6为字体大小的一半

            for (int i = 0; i < Ycounts; i++)
            {
                //画Y轴刻度
                string strY = (i * 2 + YminValue).ToString();//Y轴刻度值
                gph.DrawString(strY, new Font("宋体", 11), Brushes.Black, new PointF(cPt.X - strY.Length*11, cPt.Y - i * (cPt.Y-cPt.X)/Ycounts-11*2f/3));//11为字体大小
                if (i != 0)
                {
                    gph.DrawLine(Pens.Black, cPt.X + 3, cPt.Y - i * (cPt.Y - cPt.X) / Ycounts , cPt.X, cPt.Y - i * (cPt.Y - cPt.X) / Ycounts);
                }
            }

            for (int i = 1; i <= month.Length; i++)
            {
                //画X轴项目
                int positionWordTian=month[i-1].IndexOf("天");
                int positionWordZhi = month[i - 1].IndexOf("至");
                int py = 0;
                if (positionWordZhi > 0)
                {
                    gph.DrawString(month[i - 1].Substring(0, positionWordZhi).PadLeft(2), new Font("宋体", 11), Brushes.Black, new PointF(cPt.X + (i - 1) * (cPt.Y-cPt.X)/month.Length-11, cPt.Y));
                    gph.DrawString(month[i - 1].Substring(positionWordZhi, 1), new Font("宋体", 11), Brushes.Black, new PointF(cPt.X + (i - 1) * (cPt.Y - cPt.X) / month.Length-11, cPt.Y + 15));//15为字体比例大小，下同
                    gph.DrawString(month[i - 1].Substring(positionWordZhi + 1, positionWordTian - positionWordZhi - 1).PadLeft(2), new Font("宋体", 11), Brushes.Black, new PointF(cPt.X + (i - 1) * (cPt.Y - cPt.X) / month.Length-11, cPt.Y + 30));
                    py = 30;
                }
                else
                {
                    gph.DrawString(month[i - 1].Substring(0, positionWordTian), new Font("宋体", 11), Brushes.Black, new PointF(cPt.X + (i - 1) * (cPt.Y - cPt.X) / month.Length-11, cPt.Y));
                }
                for (int j = positionWordTian; j < month[i - 1].Length;j++ )
                    gph.DrawString(month[i - 1].Substring(j, 1), new Font("宋体", 11), Brushes.Black, new PointF(cPt.X + (i - 1) * (cPt.Y - cPt.X) / month.Length-11, cPt.Y + (j - positionWordTian + 1) * 15 + py));
                //画X轴刻度
                if (i != 0)
                {
                    gph.DrawLine(Pens.Black, cPt.X + (i - 1) * (cPt.Y - cPt.X) / month.Length, cPt.Y-3, cPt.X + (i - 1) * (cPt.Y - cPt.X) / month.Length, cPt.Y);
                }
                //画点
                float YpointPosition = (cPt.Y - cPt.X) / (Ycounts * 2f);
                gph.DrawEllipse(Pens.Black, cPt.X + (i - 1) * (cPt.Y - cPt.X) / month.Length, cPt.Y - (d[i - 1] - YminValue) * YpointPosition - 1.5F, 3, 3);
                gph.FillEllipse(new SolidBrush(Color.Black), cPt.X + (i - 1) * (cPt.Y - cPt.X) / month.Length, cPt.Y - (d[i - 1] - YminValue) * YpointPosition - 1.5F, 3, 3);
                //画折线
                if (i > 1) gph.DrawLine(Pens.Red, cPt.X + (i - 2) * (cPt.Y - cPt.X) / month.Length, cPt.Y - (d[i - 2] - YminValue) * YpointPosition - 1.5F, cPt.X + (i - 1) * (cPt.Y - cPt.X) / month.Length, cPt.Y - (d[i - 1] - YminValue) * YpointPosition - 1.5F);
            }
            pictureBox1.Image = bMap;
        }
    }
}

 效果图如下：