又一个验证码程序

一个验证码程序，今天在网上无意中看到的，先收藏了：





ValidCode

using System;

using System.Drawing;

using System.IO;

using System.Text;

using System.Drawing.Imaging;

using System.Security.Cryptography;

using System.Drawing.Drawing2D;

public partial class ValidCode : System.Web.UI.Page

{

protected override void OnInit(EventArgs e)

{

base.OnInit(e);

string authStr = CreateAuthStr(4);

VerifyImage verifyimg = new VerifyImage(authStr, 90, 50);

System.Drawing.Bitmap image = verifyimg.Image;

System.Web.HttpContext.Current.Response.ContentType = "image/pjpeg";

//Session["AuthStr"] = authStr.ToLower();

image.Save(this.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);

}

/**//// <summary>

/// 产生验证码

/// </summary>

/// <returns>验证码</returns>

public static string CreateAuthStr(int len)

{

int number;

StringBuilder checkCode = new StringBuilder();

Random random = new Random();

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

{

number = random.Next();

if (number % 2 == 0)

{

checkCode.Append((char)('0' + (char)(number % 10)));

}

else

{

checkCode.Append((char)('A' + (char)(number % 26)));

}

}

return checkCode.ToString();

}

}

/**//// <summary>

/// 验证码图片类

/// </summary>

public class VerifyImage

{

/**//// <summary>

/// 要显示的文字

/// </summary>

public string Text

{

get { return this.text; }

}

/**//// <summary>

/// 图片

/// </summary>

public Bitmap Image

{

get { return this.image; }

}

/**//// <summary>

/// 宽度

/// </summary>

public int Width

{

get { return this.width; }

}

/**//// <summary>

/// 高度

/// </summary>

public int Height

{

get { return this.height; }

}

private string text;

private int width;

private int height;

private Bitmap image;

private static byte[] randb = new byte[4];

private static RNGCryptoServiceProvider rand = new RNGCryptoServiceProvider();

/**//// <summary>

/// 构造函数

/// </summary>

/// <param name="code">要显示的验证码</param>

/// <param name="width">宽度</param>

/// <param name="height">高度</param>

public VerifyImage(string code, int width, int height)

{

this.text = code;

this.width = width;

this.height = height;

this.GenerateImage();

}

~VerifyImage()

{

Dispose(false);

}

public void Dispose()

{

GC.SuppressFinalize(this);

this.Dispose(true);

}

protected virtual void Dispose(bool disposing)

{

if (disposing)

this.image.Dispose();

}

private FontFamily[] fonts = {

new FontFamily("Times New Roman"),

new FontFamily("Georgia"),

new FontFamily("Arial"),

new FontFamily("Comic Sans MS")

};

public static int Next()

{

rand.GetBytes(randb);

int value = BitConverter.ToInt32(randb, 0);

if (value < 0) value = -value;

return value;

}

public static int Next(int max)

{

rand.GetBytes(randb);

int value = BitConverter.ToInt32(randb, 0);

value = value % (max + 1);

if (value < 0) value = -value;

return value;

}

public static int Next(int min, int max)

{

int value = Next(max - min) + min;

return value;

}

/**//// <summary>

/// 生成验证码图片

/// </summary>

private void GenerateImage()

{

Bitmap bitmap = new Bitmap(this.width, this.height, PixelFormat.Format32bppArgb);

Graphics g = Graphics.FromImage(bitmap);

Rectangle rect = new Rectangle(0, 0, this.width, this.height);

g.SmoothingMode = SmoothingMode.AntiAlias;

g.Clear(Color.White);

int emSize = Next(3) + 18;//(int)((this.width - 20) * 2 / text.Length);

FontFamily family = fonts[Next(fonts.Length - 1)];

Font font = new Font(family, emSize, FontStyle.Bold);

SizeF measured = new SizeF(0, 0);

SizeF workingSize = new SizeF(this.width, this.height);

while (emSize > 2 && (measured = g.MeasureString(text, font)).Width > workingSize.Width || measured.Height > workingSize.Height)

{

font.Dispose();

font = new Font(family, emSize -= 2);

}

SolidBrush drawBrush = new SolidBrush(Color.FromArgb(Next(100), Next(100), Next(100)));

for (int x = 0; x < 3; x++)

{

Pen linePen = new Pen(Color.FromArgb(Next(150), Next(150), Next(150)), 1);

g.DrawLine(linePen, new PointF(0.0F + Next(20), 0.0F + Next(this.height)), new PointF(0.0F + Next(this.width), 0.0F + Next(this.height)));

}

for (int x = 0; x < this.text.Length; x++)

{

drawBrush.Color = Color.FromArgb(Next(150) + 20, Next(150) + 20, Next(150) + 20);

PointF drawPoint = new PointF(0.0F + Next(4) + x * 15, 8.0F + Next(4));

g.DrawString(this.text[x].ToString(), font, drawBrush, drawPoint);

}

double distort = Next(5, 10) * (Next(10) == 1 ? 1 : -1);

using (Bitmap copy = (Bitmap)bitmap.Clone())

{

for (int y = 0; y < height; y++)

{

for (int x = 0; x < width; x++)

{

int newX = (int)(x + (distort * Math.Sin(Math.PI * y / 84.0)));

int newY = (int)(y + (distort * Math.Cos(Math.PI * x / 54.0)));

if (newX < 0 || newX >= width) newX = 0;

if (newY < 0 || newY >= height) newY = 0;

bitmap.SetPixel(x, y, copy.GetPixel(newX, newY));

}

}

}

//g.DrawRectangle(new Pen(Color.Silver), 0, 0, bitmap.Width - 1, bitmap.Height - 1);

font.Dispose();

drawBrush.Dispose();

g.Dispose();

this.image = bitmap;

}

}