makecheckcode.txt

在网站的登录网页表单中生成需要填写中校验码

第一步：定义一个生成验证码的类；

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Web.UI;
using System.Drawing.Drawing2D;
using System.IO;
/// <summary>
/// 生成验证码的类
///
public class ValidateNumber
{
public ValidateNumber()
{
}
/// <summary>
/// 验证码的最大长度
/// </summary>
public int MaxLength
{
?? get{return 10;}
}
/// <summary>
/// 验证码的最小长度
/// </summary>
public int MinLength
{
?? get{return 1;}
}
/// <summary>
/// 生成验证码
/// </summary>
/// <param name="length">指定验证码的长度</param>
/// <returns></returns>
public string CreateValidateNumber(int length)
{
?? int[] randMembers=new int[length];
?? int[] validateNums=new int[length];
?? string validateNumberStr="";
?? //生成起始序列值
?? int seekSeek=unchecked((int)DateTime.Now.Ticks);
?? Random seekRand=new Random(seekSeek);
?? int beginSeek=(int)seekRand.Next(0,Int32.MaxValue-length*10000);
?? int[] seeks=new int[length];
?? for(int i=0;i<length;i++)
?? {
??? beginSeek+=10000;
??? seeks[i]=beginSeek;
?? }
?? //生成随机数字
?? for(int i=0;i<length;i++)
?? {
??? Random rand=new Random(seeks[i]);
??? int pownum=1*(int)Math.Pow(10,length);
??? randMembers[i]=rand.Next(pownum,Int32.MaxValue);
?? }
?? //抽取随机数字
?? for(int i=0;i<length;i++)
?? {
??? string numStr=randMembers[i].ToString();
??? int numLength=numStr.Length;
??? Random rand=new Random();
??? int numPosition=rand.Next(0,numLength-1);
??? validateNums[i]=Int32.Parse(numStr.Substring(numPosition,1));
?? }
?? //生成验证码
?? for(int i=0;i<length;i++)
?? {
??? validateNumberStr+=validateNums[i].ToString();
?? }
?? return validateNumberStr;
}
/// <summary>
/// 创建验证码的图片
/// </summary>
/// <param name="containsPage">要输出到的page对象</param>
/// <param name="validateNum">验证码</param>
public void CreateValidateGraphic(Page containsPage,string validateNum)
{
?? Bitmap image=new Bitmap((int)Math.Ceiling(validateNum.Length*12.5),22);
?? Graphics g=Graphics.FromImage(image);
?? try
?? {
??? //生成随机生成器
??? Random random=new Random();
??? //清空图片背景色
??? g.Clear(Color.White);
??? //画图片的干扰线
??? for(int i=0;i<25;i++)
??? {
???? int x1=random.Next(image.Width);
???? int x2=random.Next(image.Width);
???? int y1=random.Next(image.Height);
???? int y2=random.Next(image.Height);
???? g.DrawLine(new Pen(Color.Silver),x1,y1,x2,y2);
??? }
??? Font font=new Font("Arial",12,(FontStyle.Bold|FontStyle.Italic));
??? LinearGradientBrush brush=new LinearGradientBrush(new Rectangle(0,0,image.Width,image.Height),
???? Color.Blue,Color.DarkRed,1.2f,true);
??? g.DrawString(validateNum,font,brush,3,2);
??? //画图片的前景干扰点
??? for(int i=0;i<100;i++)
??? {
???? int x=random.Next(image.Width);
???? int y=random.Next(image.Height);
???? image.SetPixel(x,y,Color.FromArgb(random.Next()));
??? }
??? //画图片的边框线
??? g.DrawRectangle(new Pen(Color.Silver),0,0,image.Width-1,image.Height-1);
??? //保存图片数据
??? MemoryStream stream=new MemoryStream();
??? image.Save(stream,ImageFormat.Jpeg);
??? //输出图片
??? containsPage.Response.Clear();
??? containsPage.Response.ContentType="image/jpeg";
??? containsPage.Response.BinaryWrite(stream.ToArray());
?? }
?? finally
?? {
??? g.Dispose();
??? image.Dispose();
?? }
}
/// <summary>
/// 得到验证码图片的长度
/// </summary>
/// <param name="validateNumLength">验证码的长度</param>
/// <returns></returns>
public static int GetImageWidth(int validateNumLength)
{
?? return (int)(validateNumLength*12.5);
}
/// <summary>
/// 得到验证码的高度
/// </summary>
/// <returns></returns>
public static double GetImageHeight()
{
?? return 22.5;
}
}