C# 登陆验证码工具类VerifyCode

using System; using System.Collections.Generic; using System.Drawing; using System.Drawing.Imaging; using System.IO; using System.Linq; using System.Text; using System.Threading.Tasks; namespace 落地页测试代码 { public class VerifyCode { public byte[] GetVerifyCode() { int codeW = 80; int codeH = 30; int fontSize = 16; string chkCode = string.Empty; //颜色列表，用于验证码、噪线、噪点  Color[] color = { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue }; //字体列表，用于验证码  string[] font = { "Times New Roman" }; //验证码的字符集，去掉了一些容易混淆的字符  char[] character = { '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'd', 'e', 'f', 'h', 'k', 'm', 'n', 'r', 'x', 'y', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' }; Random rnd = new Random(); //生成验证码字符串  for (int i = 0; i < 4; i++) { chkCode += character[rnd.Next(character.Length)]; } //写入Session、验证码MD5加密 WebHelper.WriteSession("nfine_session_verifycode", Md5.md5(chkCode.ToLower(), 16)); //创建画布 Bitmap bmp = new Bitmap(codeW, codeH); Graphics g = Graphics.FromImage(bmp); g.Clear(Color.White); //画噪线  for (int i = 0; i < 3; i++) { int x1 = rnd.Next(codeW); int y1 = rnd.Next(codeH); int x2 = rnd.Next(codeW); int y2 = rnd.Next(codeH); Color clr = color[rnd.Next(color.Length)]; g.DrawLine(new Pen(clr), x1, y1, x2, y2); } //画验证码字符串  for (int i = 0; i < chkCode.Length; i++) { string fnt = font[rnd.Next(font.Length)]; Font ft = new Font(fnt, fontSize); Color clr = color[rnd.Next(color.Length)]; g.DrawString(chkCode[i].ToString(), ft, new SolidBrush(clr), (float)i * 18, (float)0); } //将验证码图片写入内存流，并将其以 "image/Png" 格式输出  MemoryStream ms = new MemoryStream(); try { bmp.Save(ms, ImageFormat.Png); return ms.ToArray(); } catch (Exception) { return null; } finally { g.Dispose(); bmp.Dispose(); } } } }