使用YZMHelper帮助类即可

复制代码 代码如下:
using System;
using System.Web;
using System.Drawing;
using System.Security.Cryptography;

namespace ProjectWenDangManage.Framework
{
/// <summary>
/// 验证码类
/// </summary>
public class Rand
{
#region 生成随机数字
/// <summary>
/// 生成随机数字
/// </summary>
/// <param name="length">生成长度</param>
public static string Number(int Length)
{
return Number(Length, false);
}

/// <summary>
/// 生成随机数字
/// </summary>
/// <param name="Length">生成长度</param>
/// <param name="Sleep">是否要在生成前将当前线程阻止以避免重复</param>
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
/// <summary>
/// 生成随机字母与数字
/// </summary>
/// <param name="IntStr">生成长度</param>
public static string Str(int Length)
{
return Str(Length, false);
}

/// <summary>
/// 生成随机字母与数字
/// </summary>
/// <param name="Length">生成长度</param>
/// <param name="Sleep">是否要在生成前将当前线程阻止以避免重复</param>
public static string Str(int Length, bool Sleep)
{
if (Sleep) System.Threading.Thread.Sleep(3);
char[] Pattern = new char[] { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '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
/// <summary>
/// 生成随机纯字母随机数
/// </summary>
/// <param name="IntStr">生成长度</param>
public static string Str_char(int Length)
{
return Str_char(Length, false);
}

/// <summary>
/// 生成随机纯字母随机数
/// </summary>
/// <param name="Length">生成长度</param>
/// <param name="Sleep">是否要在生成前将当前线程阻止以避免重复</param>
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
}

/// <summary>
/// 验证图片类
/// </summary>
public class YZMHelper
{
#region 私有字段
private string text;
private Bitmap image;
private int letterCount = 4; //验证码位数
private int letterWidth = 16; //单个字体的宽度范围
private int letterHeight = 20; //单个字体的高度范围
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
/// <summary>
/// 验证码
/// </summary>
public string Text
{
get { return this.text; }
}

/// <summary>
/// 验证码图片
/// </summary>
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
/// <summary>
/// 获得下一个随机数
/// </summary>
/// <param name="max">最大值</param>
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;
}

/// <summary>
/// 获得下一个随机数
/// </summary>
/// <param name="min">最小值</param>
/// <param name="max">最大值</param>
private static int Next(int min, int max)
{
int value = Next(max - min) + min;
return value;
}
#endregion

#region 公共方法
/// <summary>
/// 绘制验证码
/// </summary>
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;
}

/// <summary>
/// 字体随机颜色
/// </summary>
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);
}

/// <summary>
/// 正弦曲线Wave扭曲图片
/// </summary>
/// <param name="srcBmp">图片路径</param>
/// <param name="bXDir">如果扭曲则选择为True</param>
/// <param name="nMultValue">波形的幅度倍数，越大扭曲的程度越高,一般为3</param>
/// <param name="dPhase">波形的起始相位,取值区间[0-2*PI)</param>
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
}
}

使用例子

复制代码 代码如下:
//实例化YZMHelper
YZMHelper y = new YZMHelper();
//然后通过CreateImage()绘制验证码
y.CreateImage();
//通过y.Text得到产生的验证码
TempData["Yzm"] = y.Text;
//通过y.Image得到产生的验证码图片
System.Drawing.Bitmap b = y.Image;
//将验证码突破保存到知道路径下
b.Save(path, System.Drawing.Imaging.ImageFormat.Png);