winform 验证码的实现代码

我这边给大家介绍两种方式

首先：放控件一个PictureBox，一个TextBox

第一种比较简单

 //private void CheckIdentifyingCde()
        //{
        //    Random r = new Random();
        //   string str = "";
        //    for (int i = 0; i < 5; i++)
        //    {
        //        int a = r.Next(0, 10);
        //        str += a;//将数字连接到一块
        //    }

        //    Bitmap bm = new Bitmap(150, 90);//创建位图对象
        //    Graphics g = Graphics.FromImage(bm);//在bm中重新画图

        //    //创建字体跟颜色数组
        //    string[] font = { "楷体", "黑体", "宋体", "斜体", "新宋体" };
        //    Color[] colors = { Color.Red, Color.Blue, Color.Green, Color.Yellow, Color.YellowGreen };

        //    //开始画图 
        //    for (int i = 0; i < 5; i++)
        //    {
        //        Point p = new Point(i * 20, 0);
        //        g.DrawString(str[i].ToString(), new Font(font[i], 20, FontStyle.Bold), new SolidBrush(colors[i]), p);
        //    }
        //    pictureBox1.Image = bm;//将位图显示到picture上
        //}

要是想要变化验证码显示的文字，直接添加一个图片的的点击事件记载该方法就可以 CheckIdentifyingCde()；

第一种自己操作看看效果，比较简单就不给大家演示啦

第二种

首先拖控件，第一种提到的两个

然后创建一个类ValidCode

最后再你要显示的页面实例化 ValidCode Code = new ValidCode(5, ValidCode.CodeType.Alphas);

第二个参数的话就是验证码的类型验证码类型：字母、数字、字母+ 数字

要是要改变验证码文字还是load加载事件哦，代码参考如下

_{^{// 图片加载验证码}}
_{^{pictureBox1.Image = Bitmap.FromStream(Code.CreateCheckCodeImage());}}

下面这步就是到你需要验证的地方验证一下就ok

// 验证
if (!this.txt_yz.Text.ToUpper().Equals(Code.CheckCode.ToUpper()))
{

MessageBox.Show(" 请输入正确的验证码!", this.Text);

this.txt_yz.Focus();

return;

}

 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



    }