注意网站与项目的区别 多了命名空间 预编译编码格式已响应报文为主 response.Charset="gb2312";无状态（对象销毁 连接断开）///viewstate 客户端 使用 一个页面使用 隐藏域自动保存值 有run="server"禁用viewstate状态(位置可以选择 页头page指令夹为全部) EnableViewState=“false” 可以用（）工具进行状态检测保存非单值元素 非表单元素状态 ViewState["num"] = num;（保存值） ----图片的序列和反序列化 ----using System.IO;using System.Runtime.Serialization.Formatters.Binary;--- //定义一个变量向页面传值 protected string str="" ; //页面加载 protected void Page_Load(object sender, EventArgs e) { //首次加载 if (!IsPostBack) { //图片保存到隐藏域中调用序列化方法 str = ImgToString(); } //提交时 else { string s = Request.Form["hd"]; //调用反序列化方法形成图片 System.Drawing.Image img = StrToImg(s); Response.ContentType = "image/jpeg"; //保存图片 img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg); } } private System.Drawing.Image StrToImg(string s) { //base64解码 byte[] buffer = Convert.FromBase64String(s); //反序列化 using (MemoryStream ms = new MemoryStream(buffer)) { BinaryFormatter bf = new BinaryFormatter(); System.Drawing.Image img = bf.Deserialize(ms) as System.Drawing.Image; return img; } } private string ImgToString() { //获取对象的路径 string path = Request.MapPath("img/IMG_4692.jpg"); //创建图片 System.Drawing.Image img = System.Drawing.Image.FromFile(path); using (MemoryStream ms = new MemoryStream()) { BinaryFormatter bf = new BinaryFormatter(); //把图片转化为流 bf.Serialize(ms, img); //序列化后的对象 写入字节数组 byte[] buffer = ms.ToArray(); //把字节数组，base64编码转换成字符串 return Convert.ToBase64String(buffer); } }------------------------------------------------------------------------------------cookie也是保存客户端 和域名相关 和浏览器相关 数据最好加密 把少量数据保存在客户端的内存或硬盘并读取出来的一种技术 cookie位置C:\user\admin\cookie 存在硬盘时会设置cookie的时间 反之在内存上 1、普通get请求无cookie 可以通过监视观察报文 2、服务器通过响应报文头里的set-cookie向浏览器设置cookie信息 3、浏览器通过请求报文里头的cookie传递浏览器存储的cookie信息 常用于登录和保存最近浏览的商品 cookie.Expires=datetime.now.addminutes(5) 设置cookie的保存时间 1、cookie的读写 //在内存中创建对象 HttpCookie hc = new HttpCookie("test"); hc.Value = DateTime.Now.ToString(); //设置过期时间 hc.Expires = DateTime.Now.AddDays(5); //输出 (并没有真正输出) Response.Cookies.Add(hc); //读cookie HttpCookie hc=Request.Cookies["test"]; if (hc != null) { Response.Write(hc.Value); } 2、cookie的删除 context.Response.ContentType = "text/plain"; //所有的cookie int count = context.Request.Cookies.Count; //遍历cookie for (int i = 0; i < count; i++) { HttpCookie hc=context.Request.Cookies[i]; //设置过期 hc.Expires = DateTime.Now.AddDays(-1); context.Response.Cookies.Add(hc); } //页面跳转 context.Response.Redirect("Login.aspx"); } 页面登录使用cookie <登陆页>if (IsPostBack) { //接收传值 string name = Request.Form["txtName"]; string pwd = Request.Form["txtPwd"]; //判断 if (name == "user" && pwd == "user") { //创建cookie对象 HttpCookie hc = new HttpCookie("name"); hc.Value = name;//赋值 设置销毁时间 hc.Expires = DateTime.Now.AddDays(7); //添加到集合 Response.Cookies.Add(hc); //页面跳转 Response.Redirect("06-LoginOver.aspx"); } } else { //页面第一次加载 if (Request.Cookies["name"] != null) { s = Request.Cookies["name"].Value; } } <登陆跳转页> if (Request.Cookies["test"] != null) { Response.Write("欢迎" + Request.Cookies["test"].Value.ToString()); } 问题： 输出同名cookie浏览器会重新赋值 反之添加 设置cookie的路径hc.Path="/文件"（根目录下的文件） cookie.Domain(域/域名)------------------------------------------------------------------------------------session服务端保存客户端的数据 在一般处理程序中必须实现接口IRequiresSessionState 添加system.web.sessionstate空间 session["name"]="";赋值 string str=session["name"].tostring();取值 销毁session.Abandon(); 对象并没有从池里销毁 Session.Clear();清空对象里的键值对 页面登录使用session sessionId 用cookie保存在浏览器的缓存内了 <页面登录> //点击提交 if (IsPostBack) { string code = Request.Form["txtCode"].ToLower(); //判断验证码是否正确 //因为session有过期机制，所以先判断是否为null if (Session["code"] !=null && code == Session["code"].ToString().ToLower()) { //当验证码正确，移除 Session.Remove("code"); string name = Request.Form["txtName"]; string pwd = Request.Form["txtPwd"]; if (name == "admin" && pwd == "admin") { //记录登录成功的状态 Session["user"] = name; Response.Redirect("08-LoginOver.aspx"); } } else { Response.Write("验证码错误"); } } <登陆跳转页> //判断是否登录 if (Session["user"] == null) { Response.Write("<script>alert('请登录');location.href='08-Login.aspx'</script>"); } else { Response.Write(Session.SessionID); Response.Write("欢迎"+Session["user"].ToString()); }-------验证码 <%@ WebHandler Language="C#" class="ValidateCode" %>using System;using System.Web;using System.Drawing;using System.Web.SessionState;public class ValidateCode : IHttpHandler,IRequiresSessionState { public void ProcessRequest(HttpContext context) { context.Response.ContentType = "image/jpeg"; string code = GetRndStr(); //保存在session上 context.Session["code"] = code; using (Bitmap img = CreateImages(code, "ch")) { img.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg); } } public bool IsReusable { get { return false; } } /// <summary> /// 数字随机数 /// </summary> /// <returns></returns> private string GetRndNum() { string code = string.Empty; Random random = new Random(); for (int i = 0; i < 4; i++) { code += random.Next(9); } return code; } /// <summary> /// 英文随机 /// </summary> /// <returns></returns> private string GetRndStr() { string Vchar = "A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z"; string[] VcArray = Vchar.Split(','); string checkCode = string.Empty; Random rand = new Random(); for (int i = 0; i < 4; i++) { int t = rand.Next(VcArray.Length); checkCode += VcArray[t]; } return checkCode; } /// <summary> /// 中文随机 /// </summary> /// <returns></returns> private string GetRndCh() { System.Text.Encoding gb = System.Text.Encoding.Default;//获取GB2312编码页（表） object[] bytes = CreateRegionCode(4);//生4个随机中文汉字编码 string[] str = new string[4]; System.Text.StringBuilder sb = new System.Text.StringBuilder(); for (int i = 0; i < 4; i++) { //根据汉字编码的字节数组解码出中文汉字 str[i] = gb.GetString((byte[])Convert.ChangeType(bytes[i], typeof(byte[]))); sb.Append(str[i].ToString()); } return sb.ToString(); } /// <summary> /// 产生随机中文字符 /// </summary> /// <param name="strlength"></param> /// <returns></returns> private static object[] CreateRegionCode(int strlength) { //定义一个字符串数组储存汉字编码的组成元素 string[] rBase = new String[16] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" }; Random rnd = new Random(); object[] bytes = new object[strlength]; for (int i = 0; i < strlength; i++) { //区位码第1位 int r1 = rnd.Next(11, 14); string str_r1 = rBase[r1].Trim(); //区位码第2位 rnd = new Random(r1 * unchecked((int)DateTime.Now.Ticks) + i); int r2; if (r1 == 13) { r2 = rnd.Next(0, 7); } else { r2 = rnd.Next(0, 16); } string str_r2 = rBase[r2].Trim(); //区位码第3位 rnd = new Random(r2 * unchecked((int)DateTime.Now.Ticks) + i);//更换随机种子 int r3 = rnd.Next(10, 16); string str_r3 = rBase[r3].Trim(); //区位码第4位 rnd = new Random(r3 * unchecked((int)DateTime.Now.Ticks) + i); int r4; if (r3 == 10) { r4 = rnd.Next(1, 16); } else if (r3 == 15) { r4 = rnd.Next(0, 15); } else { r4 = rnd.Next(0, 16); } string str_r4 = rBase[r4].Trim(); //定义两个字节变量存储产生的随机汉字区位码 byte byte1 = Convert.ToByte(str_r1 + str_r2, 16); byte byte2 = Convert.ToByte(str_r3 + str_r4, 16); //将两个字节变量存储在字节数组中 byte[] str_r = new byte[] { byte1, byte2 }; //将产生的一个汉字的字节数组放入object数组中 bytes.SetValue(str_r, i); } return bytes; } /// <summary> /// 画图片的背景图+干扰线 /// </summary> /// <param name="checkCode"></param> /// <returns></returns> private Bitmap CreateImages(string checkCode, string type) { int step = 0; if (type == "ch") { step = 5;//中文字符，边界值做大 } int iwidth = (int)(checkCode.Length * (13 + step)); System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 22); Graphics g = Graphics.FromImage(image); g.Clear(Color.White);//清除背景色 Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };//定义随机颜色 string[] font = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体" }; Random rand = new Random(); for (int i = 0; i < 50; i++) { int x1 = rand.Next(image.Width); int x2 = rand.Next(image.Width); int y1 = rand.Next(image.Height); int y2 = rand.Next(image.Height); g.DrawLine(new Pen(Color.LightGray, 1), x1, y1, x2, y2);//根据坐标画线 } for (int i = 0; i < checkCode.Length; i++) { int cindex = rand.Next(7); int findex = rand.Next(5); Font f = new System.Drawing.Font(font[findex], 10, System.Drawing.FontStyle.Bold); Brush b = new System.Drawing.SolidBrush(c[cindex]); int ii = 4; if ((i + 1) % 2 == 0) { ii = 2; } g.DrawString(checkCode.Substring(i, 1), f, b, 3 + (i * (12 + step)), ii); } g.DrawRectangle(new Pen(Color.Black, 0), 0, 0, image.Width - 1, image.Height - 1); System.IO.MemoryStream ms = new System.IO.MemoryStream(); return image; }<img οnclick="this.src='ValidateCode.ashx?_='+Math.random()" title="看不清？" style="cursor:pointer" src="ValidateCode.ashx" /><input type="text" name="txtCode" /><br />οnclick="this.src='ValidateCode.ashx?_='+Math.random()"鼠标点击随机生成------------------------------------------------------------------------------------application服务端保存共享数据 应用--当前在线人数 session时间设定 <sessionState timeout="1"></sessionState>web.config 新建一个全局处理程序 protected void Application_Start(object sender, EventArgs e) { Application.Lock(); Application["count"] = 0; Application.UnLock(); } protected void Session_Start(object sender, EventArgs e) { Application.Lock(); Application["count"] = Convert.ToInt32(Application["count"]) + 1; Application.UnLock(); } protected void Application_BeginRequest(object sender, EventArgs e) { } protected void Application_AuthenticateRequest(object sender, EventArgs e) { } protected void Application_Error(object sender, EventArgs e) { } protected void Session_End(object sender, EventArgs e) { Application.Lock(); Application["count"] = Convert.ToInt32(Application["count"]) - 1; Application.UnLock(); } protected void Application_End(object sender, EventArgs e) { }
转载于:https://www.cnblogs.com/eric-gms/p/3464885.html
