調用「json_encode」後PHP頭和會話標籤不工作

Question

我使用Ajax將登錄表單細節從HTML傳遞到PHP。細節得到正確傳遞，並且所有功能都能正常工作並且警報也基於輸出進行工作。

但是，如果我在json_encode之下添加以下會話語句，則不起作用。在執行「檢查元素」後，Chrome的「網絡標籤」中的輸出是正確的，但標題功能不起作用，並且警報也不會在成功或失敗時在Ajax中指定。

下面是代碼：

<?php 
    ob_start(); 
    session_start(); 
    $servername = "localhost"; 
    $username = "root"; 
    $password = ""; 
    $dbname = "kites"; 

    //Create Connection 
    $conn = mysqli_connect($servername, $username, $password, $dbname); 

    //Check connection 
    if(!$conn) 
    { 
    die("Connection failed: " . mysqli_connect_error()); 
    alert("Connection failed"); 
    } 
    else 
    { 
    if(empty($_POST['loginusername']) && empty($_POST['loginpassword'])) 
    { 
     echo json_encode(array('status'=>false,'msg'=>'No arguments provided')); 
    } 
    else 
    { 

    $loginusername = $_POST['loginusername']; 
    $loginpassword = $_POST['loginpassword']; 

    $stmt = $conn->prepare("SELECT * FROM register_form WHERE username = ?"); 
    $stmt->bind_param("s", $loginusername); 

    if($stmt->execute()) 
    { 
    $result = $stmt->get_result(); 
    $num_of_rows = $result->num_rows; 
    if($num_of_rows > 0) 
    { 
     $user = $result->fetch_assoc(); 
     $salt = $user['salt']; 
     $encrypted_password = $user['password']; 
     function checkhashSSHA($salt,$password) 
     { 
     $hash = base64_encode(sha1($password . $salt, true) . $salt); 
     return $hash; 
     } 
     $hash = checkhashSSHA($salt,$loginpassword); 
     if($encrypted_password == $hash) 
     { 
     echo json_encode(array('status'=>true, 'msg'=>'Login Successfull')); 
     session_regenerate_id(); 
     $_SESSION['username']=$loginusername; 
     session_write_close(); 
     //here you can redirect on your file which you want to show after login just change filename ,give it to your filename. 
     header("Location:http://localhost/kites/profile.php"); 
     } 
     else 
     { 
     echo json_encode(array('status'=>false,'msg'=>$encrypted_password)); 
     } 
    } 
    else 
    { 
     echo json_encode(array('status'=>false,'msg'=>'Wrong username. Please check it and try again')); 
    } 
    } 
    else 
    { 
    echo json_encode(array('status'=>false,'msg'=>'Something went wrong. Please try again!')); 
    } 
} } ?> 

如果我刪除下面的語句：

session_regenerate_id(); 
$_SESSION['username']=$loginusername; 
session_write_close(); 
header("Location:http://localhost/kites/profile.php"); 

的代碼工作正常。

Answer 1

的代碼塊，你越來越錯誤： 您更改到

session_regenerate_id(); 
$_SESSION['username']=$loginusername; 
session_write_close(); 
echo json_encode(array('status'=>true, 'msg'=>'Login Successfull')); 

而在你的Ajax成功功能，你可以這樣做：

if(status){ 
    //redirect using window.location 
    window.location = "your_redirect_url"; 
} 

P

Answer 2

發送任何輸出後，您無法在PHP中發送標題。使用輸出緩衝 - 用於解決方法

ob_start(); // you have already start buffering. that's correct 
... 
echo json_encode(array('status'=>true, 'msg'=>'Login Successfull')); 
session_regenerate_id(); 
$_SESSION['username']=$loginusername; 
session_write_close(); 
//here you can redirect on your file which you want to show after login just change filename ,give it to your filename. 
header("Location:http://localhost/kites/profile.php"); 
ob_end_flush(); 
... 

但畢竟，你不應該由header Ajax調用中使用重定向。它不會按預期工作。