我需要保持一个会话存活30分钟，然后销毁它。
当前回答
PHP是如何处理会话的，初学者很难理解。这可能会帮助他们概述会话的工作原理: 会话如何工作(自定义会话处理程序)
其他回答
PHP会话在30分钟内到期的简单方法。
注意:如果你想改变时间，只需要改变30和你想要的时间，不要改变* 60:这将给出分钟。
分钟:(30 * 60) (n * 24 * 60 * 60) n = no天
login。
<?php
session_start();
?>
<html>
<form name="form1" method="post">
<table>
<tr>
<td>Username</td>
<td><input type="text" name="text"></td>
</tr>
<tr>
<td>Password</td>
<td><input type="password" name="pwd"></td>
</tr>
<tr>
<td><input type="submit" value="SignIn" name="submit"></td>
</tr>
</table>
</form>
</html>
<?php
if (isset($_POST['submit'])) {
$v1 = "FirstUser";
$v2 = "MyPassword";
$v3 = $_POST['text'];
$v4 = $_POST['pwd'];
if ($v1 == $v3 && $v2 == $v4) {
$_SESSION['luser'] = $v1;
$_SESSION['start'] = time(); // Taking now logged in time.
// Ending a session in 30 minutes from the starting time.
$_SESSION['expire'] = $_SESSION['start'] + (30 * 60);
header('Location: http://localhost/somefolder/homepage.php');
} else {
echo "Please enter the username or password again!";
}
}
?>
HomePage.php
<?php
session_start();
if (!isset($_SESSION['luser'])) {
echo "Please Login again";
echo "<a href='http://localhost/somefolder/login.php'>Click Here to Login</a>";
}
else {
$now = time(); // Checking the time now when home page starts.
if ($now > $_SESSION['expire']) {
session_destroy();
echo "Your session has expired! <a href='http://localhost/somefolder/login.php'>Login here</a>";
}
else { //Starting this else one [else1]
?>
<!-- From here all HTML coding can be done -->
<html>
Welcome
<?php
echo $_SESSION['luser'];
echo "<a href='http://localhost/somefolder/logout.php'>Log out</a>";
?>
</html>
<?php
}
}
?>
LogOut.php
<?php
session_start();
session_destroy();
header('Location: http://localhost/somefolder/login.php');
?>
请使用以下代码块在您的包括文件加载在每一页。
$expiry = 1800 ;//session expiry required after 30 mins
if (isset($_SESSION['LAST']) && (time() - $_SESSION['LAST'] > $expiry)) {
session_unset();
session_destroy();
}
$_SESSION['LAST'] = time();
if (isSet($_SESSION['started'])){
if((mktime() - $_SESSION['started'] - 60*30) > 0){
//Logout, destroy session, etc.
}
}
else {
$_SESSION['started'] = mktime();
}
PHP是如何处理会话的，初学者很难理解。这可能会帮助他们概述会话的工作原理: 会话如何工作(自定义会话处理程序)
使用下面这样的函数其实很简单。它使用数据库表名'sessions'与字段'id'和'time'。
每次当用户再次访问您的站点或服务时，您都应该调用这个函数来检查它的返回值是否为TRUE。如果是FALSE，用户已经过期，会话将被销毁(注意:这个函数使用一个数据库类来连接和查询数据库，当然你也可以在你的函数中这样做或类似的事情):
function session_timeout_ok() {
global $db;
$timeout = SESSION_TIMEOUT; //const, e.g. 6 * 60 for 6 minutes
$ok = false;
$session_id = session_id();
$sql = "SELECT time FROM sessions WHERE session_id = '".$session_id."'";
$rows = $db->query($sql);
if ($rows === false) {
//Timestamp could not be read
$ok = FALSE;
}
else {
//Timestamp was read succesfully
if (count($rows) > 0) {
$zeile = $rows[0];
$time_past = $zeile['time'];
if ( $timeout + $time_past < time() ) {
//Time has expired
session_destroy();
$sql = "DELETE FROM sessions WHERE session_id = '" . $session_id . "'";
$affected = $db -> query($sql);
$ok = FALSE;
}
else {
//Time is okay
$ok = TRUE;
$sql = "UPDATE sessions SET time='" . time() . "' WHERE session_id = '" . $session_id . "'";
$erg = $db -> query($sql);
if ($erg == false) {
//DB error
}
}
}
else {
//Session is new, write it to database table sessions
$sql = "INSERT INTO sessions(session_id,time) VALUES ('".$session_id."','".time()."')";
$res = $db->query($sql);
if ($res === FALSE) {
//Database error
$ok = false;
}
$ok = true;
}
return $ok;
}
return $ok;
}
