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图片 ,系统提供2中生成验证码的函数

选择字号: 超大 标准 发布时间:2009-8-17 23:48:56 | 作者:admin | 0个评论 | 人浏览

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;
using System.IO;

namespace CA_Web.UIadmin
{
    public partial class checkCode : System.Web.UI.Page
    {
        private void Page_Load(object sender, System.EventArgs e)
        {
            CreatePic2();
        }

        #region 第一个方法
        public void CreatePic()
        {
            // 在此处放置用户代码以初始化页面
            string vnum;
            vnum = GetByRndNum(6);
            Response.ClearContent(); //需要输出图象信息 要修改HTTP头
            Response.ContentType = "image/Png";
            Response.BinaryWrite(GetByValidateCode(vnum).ToArray());

        }
        public MemoryStream GetByValidateCode(string VNum)//返回内存流
        {
            Bitmap Img = null;
            Graphics g = null;
            MemoryStream ms = null;
            Random random = new Random();
            int gheight = VNum.Length * 12;
            Img = new Bitmap(gheight, 24);
            g = Graphics.FromImage(Img);
            Font f = new Font("Arial", 12, FontStyle.Bold);

            g.Clear(GetByRandColor(204, 255));//设定背景色
            Pen blackPen = new Pen(Color.Ivory, 3);
            for (int i = 0; i < 155; i++)// 随机产生干扰线,使图象中的认证码不易被其它程序探测到
            {
                int x = random.Next(gheight);
                int y = random.Next(20);
                int xl = random.Next(6);
                int yl = random.Next(2);
                g.DrawLine(blackPen, x, y, x + xl, y + yl);
            }
            SolidBrush s = new SolidBrush(Color.SandyBrown);
            g.DrawString(VNum, f, s, 3, 3);
            ms = new MemoryStream();
            Img.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
            g.Dispose();
            Img.Dispose();
            return ms;
        }
        //-----------------给定范围获得随机颜色------------
        Color GetByRandColor(int fc, int bc)
        {
            Random random = new Random();

            if (fc > 255) fc = 255;
            if (bc > 255) bc = 255;
            //if(ac>255) ac=255;
            int r = fc + random.Next(bc - fc);
            int g = fc + random.Next(bc - fc);
            int b = fc + random.Next(bc - bc);
            Color rs = Color.FromArgb(r, g, b);
            return rs;
        }
        //-----------------------取随机产生的认证码(6位数字)
        public string GetByRndNum(int VcodeNum)
        {
            string Vchar = "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";
            string[] VcArray = Vchar.Split(',');
            string VNum = "";
            int temp = -1;//记录上次随机数值,尽量避免生产几个一样的随机数
            //采用一个简单的算法以保证生成随机数的不同
            Random rand = new Random();
            for (int i = 1; i < VcodeNum + 1; i++)
            {
                if (temp != -1)
                {
                    rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks));
                }
                int t = rand.Next(35);
                if (temp != -1 && temp == t)
                {
                    return GetByRndNum(VcodeNum);
                }
                temp = t;
                VNum += VcArray[t];
            }
            return VNum;
        }
        #endregion

        #region 第二个方法

        protected void CreatePic2()
        {
            checkCode v = new checkCode();
            v.Length = this.length;
            v.FontSize = this.fontSize;
            v.Chaos = this.chaos;
            v.BackgroundColor = this.backgroundColor;
            v.ChaosColor = this.chaosColor;
            v.CodeSerial = this.codeSerial;
            v.Colors = this.colors;
            v.Fonts = this.fonts;
            v.Padding = this.padding;
            string code = v.CreateVerifyCode();                //取随机码
            v.CreateImageOnPage(code, this.Context);        // 输出图片
            Session["CheckCode"] = code;
            //Response.Cookies.Add(new HttpCookie("CheckCode", code.ToUpper()));// 使用Cookies取验证码的值
        }
        #region 验证码长度(默认6个验证码的长度)
        int length = 4;
        public int Length
        {
            get { return length; }
            set { length = value; }
        }
        #endregion

        #region 验证码字体大小(为了显示扭曲效果,默认40像素,可以自行修改)
        int fontSize = 10;
        public int FontSize
        {
            get { return fontSize; }
            set { fontSize = value; }
        }
        #endregion

        #region 边框补(默认1像素)
        int padding = 2;
        public int Padding
        {
            get { return padding; }
            set { padding = value; }
        }
        #endregion

        #region 是否输出燥点(默认不输出)
        bool chaos = true;
        public bool Chaos
        {
            get { return chaos; }
            set { chaos = value; }
        }
        #endregion

        #region 输出燥点的颜色(默认灰色)
        Color chaosColor = Color.LightGray;
        public Color ChaosColor
        {
            get { return chaosColor; }
            set { chaosColor = value; }
        }
        #endregion

        #region 自定义背景色(默认白色)
        Color backgroundColor = Color.White;
        public Color BackgroundColor
        {
            get { return backgroundColor; }
            set { backgroundColor = value; }
        }
        #endregion

        #region 自定义随机颜色数组
        Color[] colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };
        public Color[] Colors
        {
            get { return colors; }
            set { colors = value; }
        }
        #endregion

        #region 自定义字体数组
        string[] fonts = { "Arial", "Georgia" };
        public string[] Fonts
        {
            get { return fonts; }
            set { fonts = value; }
        }
        #endregion

        #region 自定义随机码字符串序列(使用逗号分隔)
        string codeSerial = "0,1,2,3,4,5,6,7,8,9";
        public string CodeSerial
        {
            get { return codeSerial; }
            set { codeSerial = value; }
        }
        #endregion

        #region 产生波形滤镜效果

        private const double PI = 3.1415926535897932384626433832795;
        private const double PI2 = 6.283185307179586476925286766559;

        /// <summary>
        /// 正弦曲线Wave扭曲图片(Edit By 51aspx.com)
        /// </summary>
        /// <param name="srcBmp">图片路径</param>
        /// <param name="bXDir">如果扭曲则选择为True</param>
        /// <param name="nMultValue">波形的幅度倍数,越大扭曲的程度越高,一般为3</param>
        /// <param name="dPhase">波形的起始相位,取值区间[0-2*PI)</param>
        /// <returns></returns>
        public System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)
        {
            System.Drawing.Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height);

            // 将位图背景填充为白色
            System.Drawing.Graphics graph = System.Drawing.Graphics.FromImage(destBmp);
            graph.FillRectangle(new SolidBrush(System.Drawing.Color.White), 0, 0, destBmp.Width, destBmp.Height);
            graph.Dispose();

            double dBaseAxisLen = bXDir ? (double)destBmp.Height : (double)destBmp.Width;

            for (int i = 0; i < destBmp.Width; i++)
            {
                for (int j = 0; j < destBmp.Height; j++)
                {
                    double dx = 0;
                    dx = bXDir ? (PI2 * (double)j) / dBaseAxisLen : (PI2 * (double)i) / dBaseAxisLen;
                    dx += dPhase;
                    double dy = Math.Sin(dx);

                    // 取得当前点的颜色
                    int nOldX = 0, nOldY = 0;
                    nOldX = bXDir ? i + (int)(dy * dMultValue) : i;
                    nOldY = bXDir ? j : j + (int)(dy * dMultValue);

                    System.Drawing.Color color = srcBmp.GetPixel(i, j);
                    if (nOldX >= 0 && nOldX < destBmp.Width
                     && nOldY >= 0 && nOldY < destBmp.Height)
                    {
                        destBmp.SetPixel(nOldX, nOldY, color);
                    }
                }
            }

            return destBmp;
        }


        #endregion

        #region 生成校验码图片
        public Bitmap CreateImageCode(string code)
        {
            int fSize = FontSize;
            int fWidth = fSize + Padding;

            int imageWidth = (int)(code.Length * fWidth) + 4 + Padding * 2;
            int imageHeight = fSize * 2 + Padding;

            System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth, imageHeight);

            Graphics g = Graphics.FromImage(image);

            g.Clear(BackgroundColor);

            Random rand = new Random();

            //给背景添加随机生成的燥点
            if (this.Chaos)
            {

                Pen pen = new Pen(ChaosColor, 0);
                int c = Length * 10;

                for (int i = 0; i < c; i++)
                {
                    int x = rand.Next(image.Width);
                    int y = rand.Next(image.Height);

                    g.DrawRectangle(pen, x, y, 1, 1);
                }
            }

            int left = 0, top = 0, top1 = 1, top2 = 1;

            int n1 = (imageHeight - FontSize - Padding * 2);
            int n2 = n1 / 4;
            top1 = n2;
            top2 = n2 * 2;

            Font f;
            Brush b;

            int cindex, findex;

            //随机字体和颜色的验证码字符
            for (int i = 0; i < code.Length; i++)
            {
                cindex = rand.Next(Colors.Length - 1);
                findex = rand.Next(Fonts.Length - 1);

                f = new System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold);
                b = new System.Drawing.SolidBrush(Colors[cindex]);

                if (i % 2 == 1)
                {
                    top = top2;
                }
                else
                {
                    top = top1;
                }

                left = i * fWidth;

                g.DrawString(code.Substring(i, 1), f, b, left, top);
            }

            //画一个边框 边框颜色为Color.Gainsboro
            g.DrawRectangle(new Pen(Color.Gainsboro, 0), 0, 0, image.Width - 1, image.Height - 1);
            g.Dispose();

            //产生波形(Add By 51aspx.com)
            image = TwistImage(image, true, 2, 1);

            return image;
        }
        #endregion

        #region 将创建好的图片输出到页面
        public void CreateImageOnPage(string code, HttpContext context)
        {
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            Bitmap image = this.CreateImageCode(code);

            image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);

            context.Response.ClearContent();
            context.Response.ContentType = "image/Jpeg";
            context.Response.BinaryWrite(ms.GetBuffer());

            ms.Close();
            ms = null;
            image.Dispose();
            image = null;
        }
        #endregion

        #region 生成随机字符码
        public string CreateVerifyCode(int codeLen)
        {
            if (codeLen == 0)
            {
                codeLen = Length;
            }

            string[] arr = CodeSerial.Split(',');

            string code = "";

            int randValue = -1;

            Random rand = new Random(unchecked((int)DateTime.Now.Ticks));

            for (int i = 0; i < codeLen; i++)
            {
                randValue = rand.Next(0, arr.Length - 1);

                code += arr[randValue];
            }

            return code;
        }
        public string CreateVerifyCode()
        {
            return CreateVerifyCode(0);
        }
        #endregion

 

        #endregion
    }
}

标签:图片  系统提供2中生成验证码的函数  

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