-------随机码生成页面 suiji.ashx
<%@ WebHandler Language="C#" Class="suiji" %>
using System; using System.Web; using System.Drawing; using System.Web.SessionState; //为了用到session 继承了IReadOnlySessionState才能用context.Session否则回出错 public class suiji : IHttpHandler, IReadOnlySessionState { public void ProcessRequest (HttpContext context) { context.Response.Cache.SetCacheability(HttpCacheability.NoCache); //特别注意，如不加，单击验证图片＇看不清换一张＇，无效果． this.CreateCheckCodeImage(GenerateCheckCode(context, "Session"), context);
}
/// <summary> /// 生成随机码图片 /// </summary> /// <param name="checkCode">随机码</param> /// <param name="context"></param> private void CreateCheckCodeImage(string checkCode, HttpContext context) { if (checkCode == null || checkCode.Trim() == String.Empty) return; System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22); Graphics g = Graphics.FromImage(image);
try { Random random = new Random(); // //生成随机生成器 g.Clear(Color.White); //清空图片背景色 for (int i = 0; i < 25; i++) //画图片的背景噪音线 { 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 System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic)); System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true); g.DrawString(checkCode, font, brush, 2, 2); for (int i = 0; i < 100; i++) //画图片的前景噪音点 { int x = random.Next(image.Width); int y = random.Next(image.Height);
image.SetPixel(x, y, Color.FromArgb(random.Next())); } g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1); //画图片的边框线 System.IO.MemoryStream ms = new System.IO.MemoryStream(); image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif); context.Response.ClearContent(); context.Response.ContentType = "image/Gif"; context.Response.BinaryWrite(ms.ToArray()); } finally { g.Dispose(); image.Dispose(); }
}
/// <summary> /// 生成随机码 /// </summary> /// <param name="context"></param> /// <param name="type">如果随机码保存在Cookie里，那么填写Cookie ； 如果保存在Session里，那么填写Session</param> /// <returns></returns> private string GenerateCheckCode(HttpContext context , string type) { int number; char code; string checkCode = String.Empty; System.Random random = new Random(); for (int i = 0; i < 4; i++) { number = random.Next();
if (number % 2 == 0) code = (char)('0' + (char)(number % 10)); else if (number % 3 == 0) code = (char)('A' + (char)(number % 26)); else code = (char)('a' + (char)(number % 26)); checkCode += code.ToString(); } if (type == "Cookie") { context.Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));//存到Cookie里． } else if (type == "Session") { context.Session["CheckCode"] = checkCode; //存到Seesion里． } return checkCode; }
public bool IsReusable { get { return false; } }
}
------jquery代码 js/default.js
$("#picsuiji").bind( "click", function(){ $("#picsuiji").attr("src","suiji.ashx?id="+Math.random()); } );
------前台页面代码
<img src="suiji.ashx" id="picsuiji" width="100" height="40" title="看不清楚换一张" /> <script src="js/Default.js" type="text/javascript" ></script>
本文转载自：http://licheng3222.blog.163.com/blog/static/610993672009161726353/
