Session

这次只举例子，从例子中学习。直接上代码，建议不要粘贴复制，用手完全照着敲出来，增强印象。（没有用到数据库）

1. 4.12.php开启会话 session_start() ;

 1 <?php
 2 /*
 3  * 
 4  * @Authors peng--jun 
 5  * @Email   1098325951@qq.com
 6  * @Date    2015-11-04 13:00:16
 7  * @Link    http://www.cnblogs.com/xs-yqz/
 8  * @version $Id$
 9  ==========================================
10  */
11 
12 session_start();
13 header("Content-type: text/html; charset=UTF-8"); 
14 $_SESSION["username"]="彭军";
15 $_SESSION["username"]="彭军军";//修改Session变量值
16 $_SESSION["age"] = 21;
17 $email = "1098325951@qq.com";
18 $_SESSION["email"] = $email;//将变量信息存储到Session中
19 $_SESSION["user"]  = array('name' =>"peng-jun" ,'pwd' => "123" ); //将数组存入Session 中
20 ?>

2. 4.13.php将session里面的值显示出来

1  header("Content-type: text/html; charset=UTF-8"); 
2  session_start();
3  echo $_SESSION["username"];
4  echo $_SESSION["age"];
5  echo $_SESSION["email"];
6  echo $_SESSION["user"];

3. 以下4.14.php通过一个表单的例子（admin ,123）来验证会话

 1 <?php
 2 /*
 3  * 
 4  * @Authors peng--jun 
 5  * @Email   1098325951@qq.com
 6  * @Date    2015-11-04 13:16:06
 7  * @Link    http://www.cnblogs.com/xs-yqz/
 8  * @version $Id$
 9  ==========================================
10  */
11  header("Content-type: text/html; charset=UTF-8"); 
12  session_start();
13  if (isset($_POST["submit"])) {
14      $user = $_POST["username"];
15      $pw = $_POST["pwd"];
16      if ($user == "admin" && $pw == "123") {
17          $_SESSION["user"] = $user;//通过这样来传递session参数
18          header('Location:4.15.php');//header的location进行页面的跳转
19      }else{
20          echo "用户名或密码错误";
21      }
22  }else{
23      echo '
24        <form method ="post" action="">
25        用户名：<input type="text" name="username" />
26        密  码：<input type ="password" name="pwd"/>
27        <input name="submit" type="submit" value="登录"/>
28        </form>
29      ';
30  }
31 ?>

4 4.15.php验证通过的页面

 header("Content-type: text/html; charset=UTF-8"); 
 session_start();
 if (isset($_SESSION['user'])) {
     echo "欢迎你，".$_SESSION['user']."<br/>
          <a href = '4.16.php?action=logout'>注销登录</a>";
 }else{
     echo "未登录用户禁止访问";
 }

5 用户注销的页面代码4.16.php

1 if ($_GET["action"] == "logout") {
2      session_start();//启动会话
3      setcookie("user","",time()-60);//将会话Cookie变量user设置为过期，即删除Cookie
4      session_unset();//删除$_SESSION中的Session变量
5      session_destroy();//销毁Session，删除Session ID
6      header("location:4.14.php");  //回到登陆页面
7  }