验证码

（1）使用前需要New一下这个类

namespace PMPOrganization.Models

{

public class ValidateCode

{



//生成随机生成器

private Random random = new Random();



//验证码的最大长度

public int MaxLength

{

get { return 10; }

}



//验证码的最小长度

public int MinLength

{

get { return 1; }

}



#region 随机生成验证码(数字)

/// <summary>

/// 随机生成验证码(数字)

/// </summary>

/// <param name="length">指定验证码的长度</param>

/// <returns></returns>

public string CreateValidateCodeByShuZi(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;

}

#endregion



#region 随机生成验证码（大小写字母+数字）

/// <summary>

/// 随机生成验证码（大、小写字母+数字）

/// </summary>

/// <param name="yzmlength">验证码的长度</param>

/// <returns></returns>

public string CreateValidateCodeByShuZiAndZiMu(int yzmlength)

{

string yanzhengma = string.Empty;

var random = new Random((int)DateTime.Now.Ticks);

const string textArray = "ABCDEFGHG23KLMNPQRSTU45VWXYZ89abcdefghijk67mnpqrstuvwxyz";

for (var i = 0; i < yzmlength; i++)

{

yanzhengma = yanzhengma + textArray.Substring(random.Next() % textArray.Length, 1);

}

return yanzhengma;

}

#endregion



#region 随机生成验证码（大写字母+数字 或者是小写字母+数字）

/// <summary>

/// 随机生成验证码（大写字母+数字 或者是小写字母+数字）

/// </summary>

/// <param name="yzmlength">验证码长度</param>

/// <returns></returns>

private string CreateValidateCodeByShuZiAndZiMu2(int yzmlength)

{

int number;

char code;

string checkcode = string.Empty;

Random random = new Random();

for (int i = 0; i < 4; i++)

{

number = random.Next();

if (number % 2 == 0)

{

code = (char)('0' + (char)(number % 10));

}

else

{

code = (char)('A' + (char)(number % 26));

}

checkcode += code.ToString();

}

return checkcode;

}

#endregion



#region 随机生成颜色



private Color GetColor()

{

var corlors = new[] { Color.DarkSeaGreen, Color.Gray, Color.DarkSalmon, Color.Lavender };

return corlors[random.Next(corlors.Length)];

}

private Color GetColor2()

{

var corlors = new[] { Color.Blue, Color.Green, Color.HotPink, Color.MediumOrchid, Color.Olive, Color.Peru, };

return corlors[random.Next(corlors.Length)];

}



#endregion



#region 创建验证码的图片

/// <summary>

/// 创建验证码的图片

/// </summary>

/// <param name="validateCode">验证码</param>

/// <param name="width">width</param>

/// <param name="height">height</param>

public byte[] CreateValidateGraphic(string validateCode, int width, int height)

{

//Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 13.0),20);

Bitmap image = new Bitmap(width, height);

Graphics g = Graphics.FromImage(image);

try

{



//清空图片背景色

g.Clear(Color.White);

//画图片的干扰线

for (int i = 0; i < 15; 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(GetColor(), 1.7f), x1, y1, x2, y2);

}



var font = new Font("微软雅黑", 15, (FontStyle.Bold | FontStyle.Italic));

var brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),

GetColor2(), GetColor2(), 1.5f, true);

g.DrawString(validateCode, font, brush, 5, 13);



//画图片的边框线

g.DrawRectangle(new Pen(Color.White), 0, 0, image.Width - 1, image.Height - 1);

//保存图片数据

var stream = new MemoryStream();

image.Save(stream, ImageFormat.Jpeg);

//输出图片流

return stream.ToArray();

}

finally

{

g.Dispose();

image.Dispose();

}

} 

#endregion



#region 得到验证码图片的长度

/// <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 * 16.0);

} 

#endregion



//得到验证码的高度

public static double GetImageHeight()

{

return 100;

}



}

}







//生成验证码

public void ShowValidateCodeImage()

{

try

{

Session["YanZhengMa"] = null;

var code = new ValidateCode();

var yanzhengma = code.CreateValidateCodeByShuZiAndZiMu(5);

var imagebytes = code.CreateValidateGraphic(yanzhengma, 90, 50);

Response.OutputStream.Write(imagebytes, 0, imagebytes.Length);

Session["YanZhengMa"] = yanzhengma;

}

catch (Exception ex)

{

Log.Error(ex, "PMPOrganization.Login::void ShowValidateCodeImage()");

}

}



 html页中<img src="/login/showValidateCodeImage" id=h/>

  jquery中$("#").attr("src", "/login/showValidateCodeImage?rom=" + Math.random());