C#系統登陸隨機驗證碼生成及其調用方法

時間 2019-12-05

標籤 c# 系統登陸隨機驗證碼生成及其調用方法欄目 C# 简体版

原文原文鏈接

話很少說，直接上代碼javascript

 public ValidateCode()
        {
        }
        /// <summary>
        /// 驗證碼的最大長度
        /// </summary>
        public int MaxLength
        {
            get { return 10; }
        }
        /// <summary>
        /// 驗證碼的最小長度
        /// </summary>
        public int MinLength
        {
            get { return 1; }
        }
        /// <summary>
        /// 生成驗證碼
        /// </summary>
        /// <param name="length">指定驗證碼的長度</param>
        /// <returns></returns>
        public string CreateValidateCode(int length)
        {
            int[] randMembers = new int[length];
            int[] validateNums = new int[length];
            string validateNumberStr = "";
            //生成起始序列值
            int seekSeek = unchecked((int)DateTime.Now.Ticks);
            Random seekRand = new Random(seekSeek);
            int beginSeek = (int)seekRand.Next(0, Int32.MaxValue - length * 10000);
            int[] seeks = new int[length];
            for (int i = 0; i < length; i++)
            {
                beginSeek += 10000;
                seeks[i] = beginSeek;
            }
            //生成隨機數字
            for (int i = 0; i < length; i++)
            {
                Random rand = new Random(seeks[i]);
                int pownum = 1 * (int)Math.Pow(10, length);
                randMembers[i] = rand.Next(pownum, Int32.MaxValue);
            }
            //抽取隨機數字
            for (int i = 0; i < length; i++)
            {
                string numStr = randMembers[i].ToString();
                int numLength = numStr.Length;
                Random rand = new Random();
                int numPosition = rand.Next(0, numLength - 1);
                validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));
            }
            //生成驗證碼
            for (int i = 0; i < length; i++)
            {
                validateNumberStr += validateNums[i].ToString();
            }
            return validateNumberStr;
        }
        /// <summary>
        /// 建立驗證碼的圖片
        /// </summary>
        /// <param name="context">要輸出到的page對象</param>
        /// <param name="validateNum">驗證碼</param>
        public void CreateValidateGraphic(string validateCode, HttpContext context)
        {
            Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), 22);
            Graphics g = Graphics.FromImage(image);
            try
            {
                //生成隨機生成器
                Random random = new Random();
                //清空圖片背景色
                g.Clear(Color.White);
                //畫圖片的干擾線
                for (int i = 0; i < 25; 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.Silver), x1, y1, x2, y2);
                }
                Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));
                LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),
                 Color.Blue, Color.DarkRed, 1.2f, true);
                g.DrawString(validateCode, font, brush, 3, 2);
                //畫圖片的前景干擾點
                for (int i = 0; i < 100; i++)
                {
                    int x = random.Next(image.Width);
                    int y = random.Next(image.Height);
                    image.SetPixel(x, y, Color.FromArgb(random.Next()));
                }
                //畫圖片的邊框線
                g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
                //保存圖片數據
                MemoryStream stream = new MemoryStream();
                image.Save(stream, ImageFormat.Jpeg);
                //輸出圖片流
                context.Response.Clear();
                context.Response.ContentType = "image/jpeg";
                context.Response.BinaryWrite(stream.ToArray());
            }
            finally
            {
                g.Dispose();
                image.Dispose();
            }
        }
        /// <summary>
        /// 獲得驗證碼圖片的長度
        /// </summary>
        /// <param name="validateNumLength">驗證碼的長度</param>
        /// <returns></returns>
        public static int GetImageWidth(int validateNumLength)
        {
            return (int)(validateNumLength * 12.0);
        }
        /// <summary>
        /// 獲得驗證碼的高度
        /// </summary>
        /// <returns></returns>
        public static double GetImageHeight()
        {
            return 22.5;
        }



        //C# MVC 升級版
        /// <summary>
        /// 建立驗證碼的圖片
        /// </summary>
        /// <param name="containsPage">要輸出到的page對象</param>
        /// <param name="validateNum">驗證碼</param>
        public byte[] CreateValidateGraphic(string validateCode)
        {
            Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), 22);
            Graphics g = Graphics.FromImage(image);
            try
            {
                //生成隨機生成器
                Random random = new Random();
                //清空圖片背景色
                g.Clear(Color.White);
                //畫圖片的干擾線
                for (int i = 0; i < 25; 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.Silver), x1, y1, x2, y2);
                }
                Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));
                LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),
                 Color.Blue, Color.DarkRed, 1.2f, true);
                g.DrawString(validateCode, font, brush, 3, 2);
                //畫圖片的前景干擾點
                for (int i = 0; i < 100; i++)
                {
                    int x = random.Next(image.Width);
                    int y = random.Next(image.Height);
                    image.SetPixel(x, y, Color.FromArgb(random.Next()));
                }
                //畫圖片的邊框線
                g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
                //保存圖片數據
                MemoryStream stream = new MemoryStream();
                image.Save(stream, ImageFormat.Jpeg);
                //輸出圖片流
                return stream.ToArray();
            }
            finally
            {
                g.Dispose();
                image.Dispose();
            }
        }

其中有兩個根據數字和字母生成圖片驗證碼的方法，相信你們可以明白，第一種是常規的WebForm後臺調用的方法，能夠i直接返回相應的驗證碼圖片，第二種則是專門爲ASP.NET準備的方法，其實就是篩檢了一點東西，而後傳入參數也發生了相應的變化，固然，還有點擊「看不清，換一張」的時候，會異步獲取新的數據，實現方法在文章末尾。java

在MVC中的Controller中以下調用：dom

 public ActionResult ShowVCode()
        {
            ValidateCode vliateCode = new ValidateCode();
            string code = vliateCode.CreateValidateCode(4);//產生驗證碼
            Session["validateCode"] = code;
            byte[] buffer = vliateCode.CreateValidateGraphic(code);//將驗證碼畫到畫布上.
            return File(buffer, "image/jpeg");
        }

前臺頁面中以下調用：異步

<tr>
                                <td>
                                    驗證碼：
                                </td>
                                <td align="left">
                                    <input type="text" class="login-text" id="code" name="vCode" value="1" />
                                </td>
                            </tr>
                            <tr>
                                <td></td>
                                <td>
                                    <img id="imgCode" src="/Login/ShowVCode?id=2" style="float: left; height: 24px;" />
                                    <div style="float: left; margin-left: 5px; margin-top: 10px;">
                                        <a href="javascript:void(0)" onclick="changeCheckCode();return false;">看不清，換一張</a>
                                    </div>
                                </td>
                            </tr>

實現的效果以下圖所示：spa

點擊「看不清換一張」切換驗證碼代碼以下：code

    <script type="text/javascript">
        $(function () {
            $("#imgCode").click(changeCheckCode);

        });
        //改變當前圖片地址
        function changeCheckCode() {
            var old = $("#imgCode").attr("src");
            var now = new Date();
            var str = old + 
            now.getDay() + 
            now.getSeconds()  +
            now.getMilliseconds();
            $("#imgCode").attr("src",str );
        }
    </script>

若是對你們有幫助，但願點個贊哈哈orm

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