using System;
using System.Web;
using System.Drawing;
using System.Security.Cryptography;
namespace DotNet.Utilities
{
///
/// 验证码类
///
public class Rand
{
#region 生成随机数字
///
/// 生成随机数字
///
public static string Number( int Length)
{
return Number(Length, false );
}
///
/// 生成随机数字
///
public static string Number( int Length, bool Sleep)
{
if (Sleep) System.Threading.Thread.Sleep(3);
string result = "" ;
System.Random random = new Random();
for ( int i = 0; i < Length; i++)
{
result += random.Next(10).ToString();
}
return result;
}
#endregion
#region 生成随机字母与数字
///
/// 生成随机字母与数字
///
public static string Str( int Length)
{
return Str(Length, false );
}
///
/// 生成随机字母与数字
///
public static string Str( int Length, bool Sleep)
{
if (Sleep) System.Threading.Thread.Sleep(3);
char [] Pattern = new char [] { Ɔ' , Ƈ' , ƈ' , Ɖ' , Ɗ' , Ƌ' , ƌ' , ƍ' , Ǝ' , Ə' , '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' };
string result = "" ;
int n = Pattern.Length;
System.Random random = new Random(~ unchecked (( int )DateTime.Now.Ticks));
for ( int i = 0; i < Length; i++)
{
int rnd = random.Next(0, n);
result += Pattern[rnd];
}
return result;
}
#endregion
#region 生成随机纯字母随机数
///
/// 生成随机纯字母随机数
///
public static string Str_char( int Length)
{
return Str_char(Length, false );
}
///
/// 生成随机纯字母随机数
///
public static string Str_char( int Length, bool Sleep)
{
if (Sleep) System.Threading.Thread.Sleep(3);
char [] Pattern = new char [] { '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' };
string result = "" ;
int n = Pattern.Length;
System.Random random = new Random(~ unchecked (( int )DateTime.Now.Ticks));
for ( int i = 0; i < Length; i++)
{
int rnd = random.Next(0, n);
result += Pattern[rnd];
}
return result;
}
#endregion
}
///
/// 验证图片类
///
public class YZMHelper
{
#region 私有字段
private string text;
private Bitmap image;
private int letterCount = 4;
private int letterWidth = 16;
private int letterHeight = 20;
private static byte [] randb = new byte [4];
private static RNGCryptoServiceProvider rand = new RNGCryptoServiceProvider();
private Font[] fonts =
{
new Font( new FontFamily( "Times New Roman" ),10 +Next(1),System.Drawing.FontStyle.Regular),
new Font( new FontFamily( "Georgia" ), 10 + Next(1),System.Drawing.FontStyle.Regular),
new Font( new FontFamily( "Arial" ), 10 + Next(1),System.Drawing.FontStyle.Regular),
new Font( new FontFamily( "Comic Sans MS" ), 10 + Next(1),System.Drawing.FontStyle.Regular)
};
#endregion
#region 公有属性
///
/// 验证码
///
public string Text
{
get { return this .text; }
}
///
/// 验证码图片
///
public Bitmap Image
{
get { return this .image; }
}
#endregion
#region 构造函数
public YZMHelper()
{
HttpContext.Current.Response.Expires = 0;
HttpContext.Current.Response.Buffer = true ;
HttpContext.Current.Response.ExpiresAbsolute = DateTime.Now.AddSeconds(-1);
HttpContext.Current.Response.AddHeader( "pragma" , "no-cache" );
HttpContext.Current.Response.CacheControl = "no-cache" ;
this .text = Rand.Number(4);
CreateImage();
}
#endregion
#region 私有方法
///
/// 获得下一个随机数
///
private 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;
}
///
/// 获得下一个随机数
///
private static int Next( int min, int max)
{
int value = Next(max - min) + min;
return value;
}
#endregion
#region 公共方法
///
/// 绘制验证码
///
public void CreateImage()
{
int int_ImageWidth = this .text.Length * letterWidth;
Bitmap image = new Bitmap(int_ImageWidth, letterHeight);
Graphics g = Graphics.FromImage(image);
g.Clear(Color.White);
for ( int i = 0; i < 2; i++)
{
int x1 = Next(image.Width - 1);
int x2 = Next(image.Width - 1);
int y1 = Next(image.Height - 1);
int y2 = Next(image.Height - 1);
g.DrawLine( new Pen(Color.Silver), x1, y1, x2, y2);
}
int _x = -12, _y = 0;
for ( int int_index = 0; int_index < this .text.Length; int_index++)
{
_x += Next(12, 16);
_y = Next(-2, 2);
string str_char = this .text.Substring(int_index, 1);
str_char = Next(1) == 1 ? str_char.ToLower() : str_char.ToUpper();
Brush newBrush = new SolidBrush(GetRandomColor());
Point thePos = new Point(_x, _y);
g.DrawString(str_char, fonts[Next(fonts.Length - 1)], newBrush, thePos);
}
for ( int i = 0; i < 10; i++)
{
int x = Next(image.Width - 1);
int y = Next(image.Height - 1);
image.SetPixel(x, y, Color.FromArgb(Next(0, 255), Next(0, 255), Next(0, 255)));
}
image = TwistImage(image, true , Next(1, 3), Next(4, 6));
g.DrawRectangle( new Pen(Color.LightGray, 1), 0, 0, int_ImageWidth - 1, (letterHeight - 1));
this .image = image;
}
///
/// 字体随机颜色
///
public Color GetRandomColor()
{
Random RandomNum_First = new Random(( int )DateTime.Now.Ticks);
System.Threading.Thread.Sleep(RandomNum_First.Next(50));
Random RandomNum_Sencond = new Random(( int )DateTime.Now.Ticks);
int int_Red = RandomNum_First.Next(180);
int int_Green = RandomNum_Sencond.Next(180);
int int_Blue = (int_Red + int_Green > 300) ? 0 : 400 - int_Red - int_Green;
int_Blue = (int_Blue > 255) ? 255 : int_Blue;
return Color.FromArgb(int_Red, int_Green, int_Blue);
}
///
/// 正弦曲线Wave扭曲图片
///
///波形的幅度倍数,越大扭曲的程度越高,一般为3 public System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)
{
double PI = 6.283185307179586476925286766559;
Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height);
Graphics graph = Graphics.FromImage(destBmp);
graph.FillRectangle( new SolidBrush(Color.White), 0, 0, destBmp.Width, destBmp.Height);
graph.Dispose();
double dBaseAxisLen = bXDir ? ( double )destBmp.Height : ( double )destBmp.Width;
for ( int i = 0; i < destBmp.Width; i++)
{
for ( int j = 0; j < destBmp.Height; j++)
{
double dx = 0;
dx = bXDir ? (PI * ( double )j) / dBaseAxisLen : (PI * ( double )i) / dBaseAxisLen;
dx += dPhase;
double dy = Math.Sin(dx);
int nOldX = 0, nOldY = 0;
nOldX = bXDir ? i + ( int )(dy * dMultValue) : i;
nOldY = bXDir ? j : j + ( int )(dy * dMultValue);
Color color = srcBmp.GetPixel(i, j);
if (nOldX >= 0 && nOldX < destBmp.Width
&& nOldY >= 0 && nOldY < destBmp.Height)
{
destBmp.SetPixel(nOldX, nOldY, color);
}
}
}
srcBmp.Dispose();
return destBmp;
}
#endregion
}
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