验证码控件

彩色验证码控件：VerifyCode.cs
using System;
using System.Web;
using System.IO;
using System.Drawing;

namespace JJS_BMT
{
 /// <summary>
 /// VerifyCode 的摘要说明。
 /// </summary>
 public class VerifyCode
 {
  // Properties

  #region 验证码长度(默认4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(默认12像素)
  int fontSize = 12;
  public int FontSize
  {
   get{ return fontSize; }
   set{ fontSize = value; }
  }
  #endregion

  #region 边框补(默认2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 = false;
  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

  // Methods

  #region 生成校验码图片
  /// <summary>
  /// 生成校验码图片
  /// </summary>
  /// <param name="code">已经生成的随机码</param>
  /// <returns>位图</returns>
  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
   g.DrawRectangle(new Pen(Color.Black,0), 0, 0, image.Width-1, image.Height-1);

   g.Dispose();

   return image;
  }
  #endregion

  #region 将创建好的图片输出到页面
  /// <summary>
  /// 将创建好的图片输出到页面
  /// </summary>
  /// <param name="code">已经生成的随机码</param>
  /// <param name="context">Web上下文</param>
  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
  /// <summary>
  /// 生成随机字符码
  /// </summary>
  /// <param name="codeLen">随机码长度</param>
  /// <returns>产生的随机码</returns>
  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

 }
}
图片：CheckCode.aspx
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace JJS_OMT.Member
{
 /// <summary>
 /// CheckCode 的摘要说明。
 /// </summary>
 public class CheckCode : System.Web.UI.Page
 {

  #region 验证码长度(默认4个验证码的长度)
  int length = 4;
  #endregion

  #region 验证码字体大小(默认12像素)
  int fontSize = 12;
  #endregion

  #region 边框补(默认2像素)
  int padding = 1;
  #endregion

  #region 是否输出燥点(默认不输出)
  bool chaos = true;
  #endregion

  #region 输出燥点的颜色(默认灰色)
  Color chaosColor = System.Drawing.Color.Pink;
  #endregion

  #region 自定义背景色(默认白色)
  Color backgroundColor = Color.White;
  #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};
  #endregion

  #region 自定义字体数组
  string[] fonts = {"Arial", "Georgia"};
  #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";
  #endregion

  private void Page_Load(object sender, System.EventArgs e)
  {
   JJS_BMT.VerifyCode v = new JJS_BMT.VerifyCode();
   
   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.ToLower();   // 使用Session["CheckCode"]取验证码的值
   
  }

  #region Web 窗体设计器生成的代码
  override protected void OnInit(EventArgs e)
  {
   //
   // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
   //
   InitializeComponent();
   base.OnInit(e);
  }
  
  /// <summary>
  /// 设计器支持所需的方法 - 不要使用代码编辑器修改
  /// 此方法的内容。
  /// </summary>
  private void InitializeComponent()
  {   
   this.Load += new System.EventHandler(this.Page_Load);
  }
  #endregion
 }
}