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
          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易盾网络。
