C#结合GDI的问题： load，click，和paint的问题

Question

gdic#

Answer 1

原文代码在这儿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;namespace wangshang
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        int a = 0;
        private void button1_Click(object sender, EventArgs e)
        {
            a = 1;
            //Invalidate();
        }        private void button2_Click(object sender, EventArgs e)
        {
            a = 0;
            Invalidate();
        }        private void Form1_Paint_1(object sender, PaintEventArgs e)
        {
            if (a == 1)
            {
                Graphics g = this.CreateGraphics();
                Pen pen1 = new Pen(Color.Blue, 2);
                float y = 150, y1, x1, x2;
                for (int x = 10; x < 1100; x++)
                {
                    x1 = (float)x;
                    x2 = (float)(x + 1);
                    y1 = (float)(150 - 50 * Math.Sin((3.14159 / 180.0) * (x - 9)));
                    g.DrawLine(pen1, x1, y, x2, y1);
                    y = y1;
                }
                System.Drawing.Drawing2D.AdjustableArrowCap linecap = new System.Drawing.Drawing2D.AdjustableArrowCap(6, 6, false);
                Pen pen2 = new Pen(Color.Blue, 3);                pen2.CustomEndCap = linecap;
                g.DrawLine(pen2, 10, 300, 10, 0);
                g.DrawLine(pen2, 10, 150, 1120, 150);
            }
        }
    }
}