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C# winform登陆框验证码的实现方法

2020-01-24 00:33:04
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本文实例为大家分享了C# winform登陆框验证码的具体代码,供大家参考,具体内容如下

1、  新建一个简单的 windows 应用项目

在默认的 Form1 中添加如下控件:

1)  Label : text = “ 输入验证码 :”

2)  TextBox : name=” txtValidCode” 输入验证码的文本框

3)  Image : name=” picValidCode” 显示验证码的图片控件

4)  Button :单击事件进行验证码验证

 2、  新建一个产生验证码的核心类,并构建其一个实例:

ValidCode validCode = new ValidCode (5,ValidCode .CodeType .Numbers)

using System;using System.Collections.Generic;using System.Text;using System.IO;using System.Drawing;using System.Drawing.Drawing2D; namespace BigHorseLib.Security{  public class ValidCode  {    #region Private Fields    private const double PI = 3.1415926535897932384626433832795;    private const double PI2 = 6.283185307179586476925286766559;    //private readonly int _wordsLen = 4;    private int _len;    private CodeType _codetype;    private readonly Single _jianju = (float )18.0;    private readonly Single _height = (float )24.0;    private string _checkCode;    #endregion    #region Public Property    public string CheckCode    {      get      {        return _checkCode;      }    }    #endregion    #region Constructors    /// <summary>    /// public constructors    /// </summary>    /// <param name="len"> 验证码长度 </param>    /// <param name="ctype"> 验证码类型:字母、数字、字母+ 数字 </param>    public ValidCode(int len, CodeType ctype)    {      this ._len = len;      this ._codetype = ctype;    }    #endregion    #region Public Field     public enum CodeType {Words, Numbers, Characters, Alphas }    #endregion    #region Private Methods     private string GenerateNumbers()    {      string strOut = "" ;      System.Random random = new Random ();       for (int i = 0; i < _len; i++)      {        string num = Convert .ToString(random.Next(10000)%10);        strOut += num;      }      return strOut.Trim();    }     private string GenerateCharacters()    {      string strOut = "" ;      System.Random random = new Random ();      for (int i = 0; i < _len; i++)      {        string num = Convert .ToString((char )(65+random.Next(10000)%26));        strOut += num;      }      return strOut.Trim();    }    //    private string GenerateAlphas()    {      string strOut = "" ;      string num = "" ;      System.Random random = new Random ();      for (int i = 0; i < _len; i++)      {        if (random.Next(500) % 2 == 0)        {          num = Convert .ToString(random.Next(10000) % 10);        }        else        {          num = Convert .ToString((char )(65 + random.Next(10000) % 26));        }        strOut += num;      }      return strOut.Trim();    }     private System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)    {      System.Drawing.Bitmap destBmp = new Bitmap (srcBmp.Width, srcBmp.Height);       // 将位图背景填充为白色      System.Drawing.Graphics graph = System.Drawing.Graphics .FromImage(destBmp);      graph.FillRectangle(new SolidBrush (System.Drawing.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 ? (PI2 * (double )j) / dBaseAxisLen : (PI2 * (double )i) / dBaseAxisLen;          dx += dPhase;          double dy = Math .Sin(dx);           // 取得当前点的颜色          int nOldX = 0, nOldY = 0;          nOldX = bXDir ? i + (int )(dy * dMultValue) : i;          nOldY = bXDir ? j : j + (int )(dy * dMultValue);          System.Drawing.Color color = srcBmp.GetPixel(i, j);          if (nOldX >= 0 && nOldX < destBmp.Width           && nOldY >= 0 && nOldY < destBmp.Height)          {            destBmp.SetPixel(nOldX, nOldY, color);          }        }      }       return destBmp;    }    #endregion    #region Public Methods    public Stream CreateCheckCodeImage()    {      string checkCode;      switch (_codetype){        case CodeType .Alphas:          checkCode = GenerateAlphas();          break ;        case CodeType .Numbers:          checkCode = GenerateNumbers();           break ;        case CodeType .Characters:          checkCode = GenerateCharacters();          break ;        default :          checkCode = GenerateAlphas();          break ;      }       this ._checkCode = checkCode;      MemoryStream ms = null ;      //      if (checkCode == null || checkCode.Trim() == String .Empty)        return null ;      Bitmap image = new System.Drawing.Bitmap ((int )Math .Ceiling((checkCode.Length * _jianju)), (int )_height);      Graphics g = Graphics .FromImage(image);      try      {        Random random = new Random ();        g.Clear(Color .White);        // 画图片的背景噪音线        for (int i = 0; i < 18; i++)        {          int x1 = random.Next(image.Width);          int x2 = random.Next(image.Width);          int y1 = random.Next(image.Height);           int y2 = random.Next(image.Height);          g.DrawLine(new Pen (Color .FromArgb(random.Next()),1), x1, y1, x2, y2);        }        Font font = new System.Drawing.Font ("Times New Roman" , 14, System.Drawing.FontStyle .Bold);        LinearGradientBrush brush = new LinearGradientBrush (new Rectangle (0, 0, image.Width, image.Height), Color .Blue, Color .DarkRed, 1.2f, true );        if (_codetype != CodeType .Words)        {          for (int i = 0; i < checkCode.Length; i++)          {            g.DrawString(checkCode.Substring(i, 1), font, brush, 2 + i * _jianju, 1);          }        }else {          g.DrawString(checkCode, font, brush, 2, 2);        }        // 画图片的前景噪音点        for (int i = 0; i < 150; i++)        {          int x = random.Next(image.Width);          int y = random.Next(image.Height);          image.SetPixel(x, y, Color .FromArgb(random.Next()));        }        // 画图片的波形滤镜效果        if (_codetype != CodeType .Words)        {          image = TwistImage(image, true , 3, 1);        }        // 画图片的边框线        g.DrawRectangle(new Pen (Color .Silver), 0, 0, image.Width - 1, image.Height - 1);         ms = new System.IO.MemoryStream ();        image.Save(ms, System.Drawing.Imaging.ImageFormat .Gif);      }      finally      {        g.Dispose();        image.Dispose();      }      return ms;    }    #endregion  }} 

3、  图片加载验证码、验证码验证

// 图片加载验证码picValidCode.Image = Bitmap .FromStream(validCode.CreateCheckCodeImage())// 验证  if (!this .txtValidCode.Text.Equals(_validCode.CheckCode))   {     MessageBox .Show(" 请输入正确的验证码!" , this .Text);     this .txtValidCode.Focus();     return ; }

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持武林网。

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