正弦波

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
namespace CoordinateSystem
{
    public partial class Form1 : Form
    {
        int orgX = 20;
        int orgY = 20;//原点距离边框左，下距离
        int move = 20;//格子间隔
        int timerI = 0;
       
        public Form1()
        {
            InitializeComponent();
            timer1.Interval = 1000;
            timer1.Enabled = true;
        }
       
        private void panel1_Paint(object sender, PaintEventArgs e)
        {
           
          

            Draw draw = new Draw();
            draw.DrawX(move,panel1,orgX,orgY);
            draw.DrawY(move, panel1, orgX, orgY);
           
        }

     

        private void button1_Click(object sender, EventArgs e)
        {
            panel1.Refresh();
            Graphics g = panel1.CreateGraphics();
          
            Pen pen = new Pen(Color.Red, 1);
            double x1 = panel1.Width/2;
            double y1 = 0;
          
            for (double x = 1; x < panel1.Width; x++)//这一块就是画正弦波的位置  panel1.width/2是偏移波到坐标系0点起始的作用。
            {
                //SIN最大值为1,而我图上用了100像素,所以有
                //100/1=100 故而y要乘100;
                // x/180*Math.PI 这个表达式把角度换成弧度值
                double y = Math.Sin(x / 180 * Math.PI) * 60;
                //SIN值一个循环为360度，而我图上用了200像素表示，所以有：
                //360/200=1.8 故而x值要除1.8

                //Matrix myMatrix = new Matrix(1, 0, 0, -1, 0, 0);
                //g.Transform = myMatrix;
                //g.TranslateTransform(0, (float)panel1.Height / 2);//画图前发这个，移动到X,Y位置
                g.DrawLine(pen, (float)x1, (float)y1 + 60, (float)(x / 1.8) + panel1.Width / 2, (float)y + 60);
                x1 = x / 1.8 + panel1.Width / 2;
                y1 = y;
            }
            //pictureBoxFrequencyDomain.Image = bitmap;

            // Graphics g = panel1.CreateGraphics();
            // g.DrawEllipse(new Pen(Color.Red, 2), panel1.Width / 2 - 50, panel1.Height / 2 - 50, 100, 100);//红色不填充圆
            // g.FillEllipse(new SolidBrush(Color.Red), panel1.Width / 2 - 50, panel1.Height / 2 - 50, 100, 100);//红色填充圆
        }
    }
    public class Draw
    {
        //X轴方法
        public void DrawX(int move,Panel panel,int orgX,int orgY)//画X轴上分格
        {
           
          
            int a = (panel.Width/2) / move;//X轴有多少格
            Graphics g = panel.CreateGraphics();
           
            g.DrawLine(new Pen(Color.Black, 3), new Point(panel.Width/2, panel.Height),//画X轴长线
                                                new Point(panel.Width/2, 0));

            for (int i = 0; i < a; i++)

            {
                g.DrawLine(new Pen(Color.Black, 3), new Point(panel.Width/2+ move * i, panel.Height/2),
                           new Point(panel.Width / 2 + move * i, panel.Height / 2 - 4));//划分+格子
                g.DrawLine(new Pen(Color.Black, 3),new Point(panel.Width / 2 - move * i, panel.Height / 2),
                            new Point(panel.Width / 2 - move * i, panel.Height / 2 - 4));//划分-格子
                g.DrawString(i.ToString(), new Font("宋体", 8f), Brushes.Black, panel.Width / 2 + move * i,
                                                                      panel.Height / 2 + 4 );//写X轴+的数字

                if (i!=0)
                {
                    g.DrawString("-" + i.ToString(), new Font("宋体", 8f), Brushes.Black, panel.Width / 2 - move * i,
                                                                                          panel.Height / 2 + 4);//写X轴-的数字
                }
               
            }
            g.DrawString("X轴", new Font("宋体", 10f), Brushes.Black, panel.Width-30, panel.Height/2+20);

        }

        public void DrawY(int move,Panel pan,int orgX,int orgY)
        {
            Graphics g = pan.CreateGraphics();
            g.DrawLine(new Pen(Color.Black, 3), new Point(0, pan.Height/2),
                                                new Point(pan.Width, pan.Height / 2));//画Y轴长线

            int a = (pan.Height/2) / move;
            for (int i = 0; i < a; i++)
            {
                g.DrawLine(new Pen(Color.Black, 3), new Point(pan.Width/2, pan.Height/2 - move * i),
                           new Point(pan.Width / 2 + 4, pan.Height / 2 - move * i));
                g.DrawLine(new Pen(Color.Black, 3), new Point(pan.Width / 2, pan.Height / 2 + move * i),
                           new Point(pan.Width / 2 + 4, pan.Height / 2 + move * i));
                if (i!=0)
                {
                    g.DrawString(i.ToString(), new Font("宋体", 8f), Brushes.Black, pan.Width / 2 - 10,
                    pan.Height / 2  - move * i);
                    g.DrawString("-"+i.ToString(), new Font("宋体", 8f), Brushes.Black, pan.Width / 2 - 15,
                    pan.Height / 2 + move * i);
                }
               
            }
            g.DrawString("Y轴", new Font("宋体", 10f),Brushes.Black, orgX, orgY - 20);
           
        }
    }
}

 

以下是运行后的界面