C#制作一个随机生成验证码程序

作者：@大木瓜
本文为作者原创，转载请注明出处：https://www.cnblogs.com/damugua/p/16743903.html

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制作一个随机生成验证码程序

一、验证码类

namespace RVaildateCode
{
    public class Class1
    {
        public void CreateCheckCodeImage(PictureBox pbox)
        {
            int number;
            char code;
            string checkCode = String.Empty;
            Random rnd = new Random();
            for (int i = 0; i < 4; i++)
            {
                number = rnd.Next();
                if (number % 2 == 0)
                    code = (char)('0' + (char)(number % 10));
                else
                    code = (char)('A' + (char)(number % 26));

                checkCode += code.ToString();
            }
            if (checkCode == null || checkCode.Trim() == String.Empty)
                return;
            Bitmap image = new Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);
            Graphics g = Graphics.FromImage(image);
            //生成随机生成器
            Random random = new Random();
            //清空图片背景色
            g.Clear(Color.White);
            //画图片的背景噪音线
            for (int i = 0; i < 2; i++)
            {
                int x1 = random.Next(image.Width);
                int x2 = random.Next(image.Width);
                int y1 = random.Next(image.Height);
                int y2 = random.Next(image.Height);
                g.DrawLine(new Pen(Color.Black), x1, y1, x2, y2);
            }
            Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));
            System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
            g.DrawString(checkCode, font, brush, 2, 2);
            //画图片的前景噪音点
            for (int i = 0; i < 100; i++)
            {
                int x = random.Next(image.Width);
                int y = random.Next(image.Height);
                image.SetPixel(x, y, Color.FromArgb(random.Next()));
            }
            //画图片的边框线
            g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width, image.Height);
            pbox.Image = image;
        }
    }
}

二、Winform代码

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

        Class1 myClass = new Class1();//实例化随机生成验证码类对象
        private void Form1_Load(object sender, EventArgs e)
        {
            myClass.CreateCheckCodeImage(pictureBox1);//生成验证码并显示
        }

        private void pictureBox1_Click(object sender, EventArgs e)
        {
            myClass.CreateCheckCodeImage(pictureBox1);//生成验证码并显示
        }
    }

三、效果图