1.生成驗證碼字元串 2.繪製干擾線 3.生成驗證碼 4.前段獲取驗證碼 5.後臺驗證 ...
1.生成驗證碼字元串
// 隨機生成指定長度的驗證碼字元串
private string RandomCode(int length) { string s = "0123456789zxcvbnmasdfghjklqwertyuiop"; StringBuilder sb = new StringBuilder(); Random rand = new Random(); int index; for(int i = 0; i < length; i++) { index = rand.Next(0, s.Length); sb.Append(s[index]); } return sb.ToString(); }
2.繪製干擾線
private void PaintInterLine(Graphics g,int num,int width,int height) { Random r = new Random(); int startX, startY, endX, endY; for(int i = 0; i < num; i++) { startX = r.Next(0, width); startY = r.Next(0, height); endX = r.Next(0, width); endY = r.Next(0, height); g.DrawLine(new Pen(Brushes.Red), startX, startY, endX, endY); } }
3.生成驗證碼
public ActionResult GetValidateCode() { byte[] data = null; string code = RandomCode(5); TempData["code"] = code; //定義一個畫板 MemoryStream ms = new MemoryStream(); using(Bitmap map=new Bitmap(100, 40)) { //畫筆,在指定畫板畫板上畫圖 //g.Dispose(); using (Graphics g = Graphics.FromImage(map)) { g.Clear(Color.White); g.DrawString(code,new Font("黑體",18.0F),Brushes.Blue,new Point(10,8)); //繪製干擾線 PaintInterLine(g, 30, map.Width, map.Height); } map.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); } data = ms.GetBuffer(); return File(data, "image/jpeg"); }
4.前段獲取驗證碼
<form method="post" id="form1" action="/ValidateCode/login"> <div class="code"> <input type="text" name="code" /> <img id="code" src="/ValidateCode/GetValidateCode/" /> <a style="text-decoration:none; cursor:pointer" id="chCode">看不清?換一個</a> </div> <div > <input type="submit" value="登錄" /> </div> </form>
5.後臺驗證
public ActionResult Login() { string code = Request.Form["code"].ToString(); if (string.IsNullOrEmpty(code)) { return Content("驗證輸不能為空"); } if (!code.Equals(TempData["code"])) { return Content("驗證輸不正確"); } return Content("驗證輸入正確"); }