C#生成随机验证码
使用YZMHelper帮助类即可
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
//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);