【转】网页验证码

又是验证码，上次用完就找不到了，唉~这毛病什么时候能改啊，转载一个被人的，感觉功能不错，又结合脚本完善了一下图片看不清情况下的刷新问题。不废话，看代码

引用

高山流水 的 c#验证码完美实现

一、函数(CheckCode.ASpx)

添加引用：

using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
using System.Text;    

/// <summary>
     /// 创建验证码,返回验证码字符串
    /// </summary>
     /// <param name="CodeLen">int CodeLe:验证码长度</param>
     /// <param name="CodeType">int CodeType:0纯数字;1纯字母;2数字与字母混合;3纯汉字</param>
     /// <returns></returns>
     /// 
    private string CreateCheckCode(int CodeLen, int CodeType)
    {
        /**参数说明：CodeLen(验证码长度）;CodeType(0纯数字，1纯字母,2,数字与字母混合，3,纯汉字)**/
        if (CodeType > 3)
        {
            CodeType = 3;
        }
        string codestring = "";
        //定义验证图片的长度与宽度
        int Clen=30*CodeLen, Cheight=40;
        //定义验证图片的背景颜色
        Color CBcolor = Color .FromArgb(200,200,200);
        string[] font = { "Bell MT", "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体","幼圆", "楷体_GB2312","仿宋_GB2312" };
        Font Cfont = new Font("Arial", 20, FontStyle.Bold);
        //产生随机验证码---------------------------------------------------------------------------------------------------
        switch (CodeType)
        {
//纯数字
            case 0:
                Random random1 = new Random();
                codestring = random1.Next((int)System.Math.Pow(10,CodeLen-1),(int) System.Math.Pow(10,CodeLen)-1).ToString();
                break;
//纯数字
//纯字母
            case 1:
              string   Vchar1 = "A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,W,X,Y,Z,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z";
                String[] VcArray1 = Vchar1.Split(',');
            int vclen1 = VcArray1.Length;
            int vcindex1;
            Random random2 = new Random();
            for (int i = 0; i < CodeLen; i++)
            {
                vcindex1 = random2.Next(vclen1);
                codestring = codestring + VcArray1[vcindex1];
            }
                break;
            case 2:
                string Vchar2 = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,W,X,Y,Z,0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z";
                String[] VcArray2 = Vchar2.Split(',');
            int vclen2 = VcArray2.Length;
            int vcindex2;
            Random random3 = new Random();
            for (int i = 0; i < CodeLen; i++)
            {
                vcindex2 = random3.Next(vclen2);
                codestring = codestring + VcArray2[vcindex2];
            }
                break;
//纯字母
//纯汉字
            case 3:
                //定义一个字符串数组储存汉字编码的组成元素 
                string[] rBase = new String[16] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

                Random rnd = new Random();
                int strlength = CodeLen*2;
                //定义一个object数组用来 
                object[] bytes = new object[strlength];

                /**/
                /*每循环一次产生一个含两个元素的十六进制字节数组，并将其放入bject数组中 
     每个汉字有四个区位码组成 
     区位码第1位和区位码第2位作为字节数组第一个元素 
     区位码第3位和区位码第4位作为字节数组第二个元素 
     */
                for (int i = 0; i < strlength; i++)
                {
                    //区位码第1位 
                    int r1 = rnd.Next(11, 14);
                    string str_r1 = rBase[r1].Trim();

                    //区位码第2位 
                    rnd = new Random(r1 * unchecked((int)DateTime.Now.Ticks) + i);//更换随机数发生器的种子避免产生重复值 
                    int r2;
                    if (r1 == 13)
                    {
                        r2 = rnd.Next(0, 7);
                    }
                    else
                    {
                        r2 = rnd.Next(0, 16);
                    }
                    string str_r2 = rBase[r2].Trim();

                    //区位码第3位 
                    rnd = new Random(r2 * unchecked((int)DateTime.Now.Ticks) + i);
                    int r3 = rnd.Next(10, 16);
                    string str_r3 = rBase[r3].Trim();

                    //区位码第4位 
                    rnd = new Random(r3 * unchecked((int)DateTime.Now.Ticks) + i);
                    int r4;
                    if (r3 == 10)
                    {
                        r4 = rnd.Next(1, 16);
                    }
                    else if (r3 == 15)
                    {
                        r4 = rnd.Next(0, 15);
                    }
                    else
                    {
                        r4 = rnd.Next(0, 16);
                    }
                    string str_r4 = rBase[r4].Trim();

                    //定义两个字节变量存储产生的随机汉字区位码 
                    byte byte1 = Convert.ToByte(str_r1 + str_r2, 16);
                    byte byte2 = Convert.ToByte(str_r3 + str_r4, 16);
                    //将两个字节变量存储在字节数组中 
                    byte[] str_r = new byte[] { byte1, byte2 };

                    //将产生的一个汉字的字节数组放入object数组中 
                    bytes.SetValue(str_r, i);

                } 
                Encoding gb = Encoding.GetEncoding("gb2312");
         //根据汉字编码的字节数组解码出中文汉字 
                for(int i=0;i<strlength/2;i++)
                {
                    codestring =codestring+ gb.GetString((byte[])Convert.ChangeType(bytes[i], typeof(byte[])));
                }
                break;
 //纯汉字
        }

        //显示验证码-----------------------------------------------------------------------------------------------------
        //创建一个图像
        //定义画笔，用于绘制文字
            Brush brush1 = new SolidBrush(Color.Black);
        Bitmap bitmap1 = new System.Drawing.Bitmap(Clen,Cheight);
        //从图像获取一个绘画面
        Graphics graphics1 = Graphics.FromImage(bitmap1);
        //清除整个绘图画面并用颜色填充
        graphics1.Clear(CBcolor);
        PointF Cpoint1=new PointF(5,5);
        Random rnd1 = new Random();
        int x1 = 0, y1 = 0;
        //绘制边框
        graphics1.DrawRectangle(new Pen(Color.Silver), 0, 0, bitmap1.Width - 1, bitmap1.Height - 1);

        //绘制文字
        for (int i = 0; i < codestring.Length; i++)
        {
            //随机字符位置
            x1 = rnd1.Next(10)+25*i;
            y1 = rnd1.Next(bitmap1.Height/4);
            Cpoint1 = new PointF(x1, y1);
            //随机字符颜色,应根据背景作适当调整以免显示模糊不清
            brush1 = new SolidBrush(Color.FromArgb(rnd1.Next(100), rnd1.Next(100), rnd1.Next(100)));
            Cfont=new Font(font[rnd1.Next(font.Length-1)],16,FontStyle.Bold);
            //随机倾斜字符
            graphics1.TranslateTransform(10, 0);
            Matrix transform = graphics1.Transform;
            transform.Shear(Convert.ToSingle( rnd1.NextDouble()-0.5),0.001f);
            graphics1.Transform = transform;
            graphics1.DrawString(codestring.Substring(i,1) , Cfont, brush1, Cpoint1);
            graphics1.ResetTransform();

        }
        //绘制干扰点
        rnd1 = new Random();
        for (int i = 0; i < 50*CodeLen; i++)
        {
            //随机干扰位置
            x1 = rnd1.Next(bitmap1.Width);
            y1 = rnd1.Next(bitmap1.Height);
            bitmap1.SetPixel(x1, y1, Color.FromArgb(rnd1.Next(50), rnd1.Next(50), rnd1.Next(50)));
        }
        //绘制干扰线
        rnd1 = new Random();
        for (int i = 0; i < 10; i++)
        {
            //随机干扰位置
            x1 = rnd1.Next(bitmap1.Width);
            y1 = rnd1.Next(bitmap1.Height);
            int x2 = rnd1.Next(bitmap1.Width);
            int y2 = rnd1.Next(bitmap1.Height);
            //随机干扰线颜色
            Pen pen1 = new Pen(Color.FromArgb(rnd1.Next(100, 255), rnd1.Next(100, 255), rnd1.Next(100, 255)));
            graphics1.DrawLine(pen1, x1, y1, x2, y2);
        }
        bitmap1.Save(Response.OutputStream, ImageFormat.Jpeg);
        bitmap1.Dispose();
        graphics1.Dispose();
        return codestring;
    }

二、调用(CheckCode.ASpx)

 protected void Page_Load(object sender, EventArgs e)
    {
        int clen = 4,ctype = 0;;
        try
        {
            clen = Convert.ToInt16(Request.QueryString["Len"].ToString().Trim());
            ctype = Convert.ToInt16(Request.QueryString["Type"].ToString().Trim());
        }
        catch
        { }
        string checkcodestr=CreateCheckCode(clen,ctype);
        //对checkcodestr进行加密
        Session["CheckStr"] = checkcodestr;
    }

三、应用(Login.aspx)

<script language="javascritp">
function reloadcode()
{
   var timenow = new Date().getMillisconds();
   document.getElementById("safecode").src="CheckCode.aspx?len=4&type=3"+timenow;
   alert("图片已更新！");
}
</script>

<a href="javascript:reloadcode();" ><img alt=点击更换图片" src="CheckCode.aspx?len=4&type=3“ /></a>

~~End ~~