asp.net验证码生成类，C#语言

using System;

using System.Drawing;

using System.Drawing.Imaging;

using System.Web.UI;

using System.Drawing.Drawing2D;

using System.IO;

namespace Validate

{

/// <summary>

/// 生成验证码的类

/// </summary>

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;

}

}

}

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