C#小例子之验证码

来源：互联网发布：linux 启动nginx命令编辑：程序博客网时间：2024/06/01 12:53

前言

我们注册某个账号或者登录某个页面的时候经常会遇到让输入验证码，那么什么是验证码？点这里它是怎么产生的？又有什么作用呢？下面介绍一种简单的验证码且看它是如何一步步演变的。

代码1.0：

namespace _02生成验证码{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void picString_Click(object sender, EventArgs e)        {            Random r = new Random();           // int num = r.Next(10);            string strNumber = "";            for (int i = 0; i < 5; i++)            {                int num = r.Next(10);                // 把随机数都存到这个字符串中                strNumber += num;            }           // Graphics g = this.CreateGraphics();            Bitmap bm = new Bitmap(110, 30);            Graphics g = Graphics.FromImage(bm);            //需要五种字体            string[] fontName = new string[] { "幼圆", "华文行楷", "楷体", "宋体", "华文新魏" };            //需要五种颜色            Color []color=new Color[]{Color .Red ,Color .Blue ,Color .Green ,Color .Pink ,Color .Black };            for (int i = 0; i < 5; i++)            {                Point point = new Point(i *20,0);                g.DrawString(strNumber[i].ToString(), new Font(fontName [i ], 20), new SolidBrush (color [i]),point  );            }                       picString.Image = bm;                   }    }}

运行结果：

看着也有点儿那么个意思，可是总觉得这些字符有点儿太清楚了，达不到要的效果需要添加点儿干扰......

代码1.1

namespace _02生成验证码{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void picString_Click(object sender, EventArgs e)        {            Random r = new Random();            // int num = r.Next(10);            string strNumber = "";            for (int i = 0; i < 5; i++)            {                int num = r.Next(10);                // 把随机数都存到这个字符串中                strNumber += num;            }            // Graphics g = this.CreateGraphics();            Bitmap bm = new Bitmap(110, 30);            Graphics g = Graphics.FromImage(bm);            //需要五种字体            string[] fontName = new string[] { "幼圆", "华文行楷", "楷体", "宋体", "华文新魏" };            //需要五种颜色            Color[] color = new Color[] { Color.Red, Color.Blue, Color.Green, Color.Pink, Color.Black };            for (int i = 0; i < 5; i++)            {                Point point = new Point(i * 20, 0);                g.DrawString(strNumber[i].ToString(), new Font(fontName[i], 20), new SolidBrush(color[i]), point);            }           <span style="color:#ff6600;"> //画线            for (int i = 0; i < 25; i++)            {                Point p_1 = new Point(r.Next(bm.Width), r.Next(bm.Height));                Point p_2 = new Point(r.Next(bm.Width), r.Next(bm.Height));                g.DrawLine(new Pen(Brushes.Gray), p_1, p_2);            }            //画点            for (int i = 0; i < 50; i++)            {                Point p_1 = new Point(r.Next(bm.Width), r.Next(bm.Height));                bm.SetPixel(p_1.X, p_1.Y, Color.Yellow);            }</span>            picString.Image = bm;        }    }}

运行结果:

这样看起来不至于太清楚也不至于看不清，朦朦胧胧、模模糊糊这样一种新鲜的验证码便“出炉了”！！犹如犹抱琵琶半遮面。

总结：

验证码的产生对于我们来说其实是有好处的，希望下次在看到它的时候能够体会它的用意，不要产生厌烦的情绪！

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