绘制验证码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace _127_绘制验证码
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        //用来记录验证码中的数字
        string correct = null;
        /// <summary>
        /// 点击PictureBox时验证码更换
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void pictureBoxCode_Click(object sender, EventArgs e)
        {
            Random r = new Random();
            string strCode = null;
            for (int i = 0; i < 5; i++)
            {
                int rNumber = r.Next(0, 10);
                strCode += rNumber;
            }
            //将正确数字记录下来
            correct = strCode;
            //创建随机数、干扰线和像素点的载体
            //创建GDI对象    (画图像)
            Bitmap bmp = new Bitmap(200, 50); //创建一个位图对象
            Graphics g = Graphics.FromImage(bmp);
            //将随机数画入bmp中
            for (int i = 0; i < 5; i++)
            {
                //字体，颜色，样式要求全随机
                string[] fonts = { "宋体", "微软雅黑", "幼圆", "华文行楷", "方正舒体", "华文彩云", "楷体" };
                Color[] colors = { Color.Yellow, Color.Red, Color.Green, Color.Blue, Color.Black, Color.Violet, Color.Orange, Color.Azure };
                FontStyle[] fStyle = { FontStyle.Regular, FontStyle.Bold, FontStyle.Italic, FontStyle.Underline, FontStyle.Strikeout };
                //五个数字的横坐标不能相同，纵坐标可以
                Point point = new Point(i * 30, 0);//在PictureBox中的坐标
                //画string   DrawString(str,font,brush,point)
                //DrawString()方法需要  string font brush point四个参数   (Font需要字体，大小，类型三个参数)                        //定义一种颜色的画笔，这个方法可以将color传入
                g.DrawString(strCode[i].ToString(), new Font(fonts[r.Next(0, fonts.Length)], r.Next(20, 55), fStyle[r.Next(0, fStyle.Length)]), new SolidBrush(colors[r.Next(0, colors.Length)]), point);
            }
            //画干扰线
            for (int i = 0; i < 70; i++)
            {
                Color[] colors = { Color.Yellow, Color.Red, Color.Green, Color.Blue, Color.Black, Color.Violet, Color.Orange, Color.Azure };
                Pen pen = new Pen(colors[r.Next(0, colors.Length)]);
                Point p1 = new Point(r.Next(0, bmp.Width), r.Next(0, bmp.Height));
                Point p2 = new Point(r.Next(0, bmp.Width), r.Next(0, bmp.Height));
                g.DrawLine(pen, p1, p2);
            }
            //生成像素粒
            for (int i = 0; i < 500; i++)
            {
                Point p = new Point(r.Next(0, bmp.Width), r.Next(0, bmp.Height));
                Color[] colors = { Color.Yellow, Color.Red, Color.Green, Color.Blue, Color.Black, Color.Violet, Color.Orange, Color.Azure };
                //在此Bitmap中设置指定像素的颜色
                bmp.SetPixel(p.X, p.Y, colors[r.Next(0, colors.Length)]);
            }
            //将图片镶嵌到PictureBox中
            pictureBoxCode.Image = bmp;
        }
        /// <summary>
        /// 点击时，判断验证码是否与用户输入的相同
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnEnter_Click(object sender, EventArgs e)
        {
            if (txtInput.Text == correct)
            {
                MessageBox.Show("输入正确");
                Object ob = new object();
                EventArgs ea = new EventArgs();
                pictureBoxCode_Click(ob, ea);
            }
            else
            {
                MessageBox.Show("输入错误，沙币");
            }
            //输入后清空文本
            txtInput.Clear();
            txtInput.Focus();
        }
        private void label1_Click(object sender, EventArgs e)
        {
            Object ob = new object();
            EventArgs ea = new EventArgs();
            pictureBoxCode_Click(ob, ea);
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            Object ob = new object();
            EventArgs ea = new EventArgs();
            pictureBoxCode_Click(ob, ea);
        }
    }
}