C# _NETMVC數字圖片驗證
阿新 • • 發佈：2020-07-20
生成圖片的幫助類
using System; using System.Drawing; using System.Drawing.Drawing2D; using System.Drawing.Imaging; using System.IO; namespace WebApplication1.Controllers { public class ValidateCode { 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; } //C# MVC 升級版 /// <summary> /// 建立驗證碼的圖片 /// </summary> /// <param name="containsPage">要輸出到的page物件</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); //儲存圖片資料 MemoryStream stream = new MemoryStream(); image.Save(stream, ImageFormat.Jpeg); //輸出圖片流 return stream.ToArray(); } finally { g.Dispose(); image.Dispose(); } } /// <summary> /// 得到驗證碼圖片的長度 /// </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> /// 得到驗證碼的高度 /// </summary> /// <returns></returns> public static double GetImageHeight() { return 22.5; } } }
控制器的寫法 (控制器名稱LoginController)
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; namespace WebApplication1.Controllers { public class LoginController : Controller { // GET: Login public ActionResult Index() { return View(); } /// <summary> /// 驗證碼的校驗 /// </summary> /// <param name="context"></param> /// <returns></returns> public ActionResult CheckCode() { //生成驗證碼 ValidateCode validateCode = new ValidateCode(); string code = validateCode.CreateValidateCode(4); Session["ValidateCode"] = code; byte[] bytes = validateCode.CreateValidateGraphic(code); return File(bytes, @"image/jpeg"); } /// <summary> /// 驗證驗證碼是否正確 /// </summary> /// <param name="num"></param> /// <returns></returns> public bool CheckValidateCode(string num) { string cnum = Session["ValidateCode"] == null ? "" : Session["ValidateCode"].ToString(); if (num == cnum && !string.IsNullOrEmpty(num)) { return true; } else { return false; } } /// <summary> /// 登入頁面 /// </summary> /// <returns></returns> public ActionResult Login() { return View(); } /// <summary> /// 登入驗證方法 /// </summary> /// <param name="Info">info為存使用者的實體,把使用者資訊與驗證資訊一起提交到這個方法裡</param> /// <returns></returns> [HttpPost] public ActionResult Login(UserInfo Info) { ///Info.Str前段傳入的驗證字串用CheckValidateCode()進行驗證 if (!CheckValidateCode(Info.Str)) { return Content("<script>javascript:alert('驗證碼輸入不正確');location.href='/Login/Login';</script>"); } ///寫個假的使用者資訊 if (Info.UserName=="張三"&&Info.PassWord=="111") { return Content("<script>javascript:alert('登入成功');location.href='/Login/Index';</script>"); } else { return Content("<script>javascript:alert('登入失敗');location.href='/Login/Login';</script>"); } } } }
前段MVC的寫法
@{ ViewBag.Title = "Login"; } <h2>Login</h2> <script> function ClickRemoveChangeCode() { var code = $("#imgCode").attr("src"); $("#imgCode").attr("src", code + "1"); } </script> @using (Html.BeginForm("Login", "Login", "post")) { <table class="table active"> <tr> <td> 使用者名稱 </td> <td> <input type="text" name="UserName" value="" /> </td> </tr> <tr> <td> 密碼 </td> <td> <input type="text" name="PassWord" value="" /> </td> </tr> <tr> <td> 驗證碼 </td> <td> <input type="text" name="Str" value="" /> </td> </tr> <tr> <td>驗證碼：</td> <td> <img src="/Login/CheckCode?ID=1" id="imgCode" alt="單擊可重新整理" onclick="ClickRemoveChangeCode()" /> <div style="float:right; margin-top: 5px;"> <a href="javascript:void(0)" onclick="ClickRemoveChangeCode();return false;">看不清，換一張</a> </div> </td> </tr> <tr> <td colspan="2"> <input type="submit" value="登入" /> </td> </tr> </table> }