ASP.NET 验证码绘制

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing;
using System.Drawing.Imaging;  

namespace Tyog.admin.html
{
    public partial class Vcode : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            Vcode v = new Vcode();
            string code = v.CreateVerifyCode();            //取随机码
            v.CreateImageOnPage(code, this.Context);       // 输出图片
            Session["CheckCode"] = code;
        }

        #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 = 40;
        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,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,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";
        public string CodeSerial{
            get {return codeSerial;}set{ codeSerial = value;}}#endregion#region 产生波形滤镜效果privateconstdouble PI =3.1415926535897932384626433832795;privateconstdouble 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>    publicSystem.Drawing.BitmapTwistImage(Bitmap srcBmp, bool bXDir,double dMultValue,double dPhase){System.Drawing.Bitmap destBmp =newBitmap(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(newSolidBrush(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publicBitmapCreateImageCode(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 =newSystem.Drawing.Bitmap(imageWidth, imageHeight);Graphics g =Graphics.FromImage(image);

            g.Clear(BackgroundColor);Random rand =newRandom();//给背景添加随机生成的燥点    if(this.Chaos){Pen pen =newPen(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 =newSystem.Drawing.Font(Fonts[findex], fSize,System.Drawing.FontStyle.Bold);
                b =newSystem.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(newPen(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,8,4);return image;}#endregion#region 将创建好的图片输出到页面publicvoidCreateImageOnPage(string code,HttpContext context){System.IO.MemoryStream ms =newSystem.IO.MemoryStream();Bitmap image =this.CreateImageCode(code);

            image.Save(ms,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publicstringCreateVerifyCode(int codeLen){if(codeLen ==0){
                codeLen =Length;}string[] arr =CodeSerial.Split(',');string code ="";int randValue =-1;Random rand =newRandom(unchecked((int)DateTime.Now.Ticks));for(int i =0; i < codeLen; i++){
                randValue = rand.Next(0, arr.Length-1);

                code += arr[randValue];}return code;}publicstringCreateVerifyCode(){returnCreateVerifyCode(0);}#endregion}}