Javascript 使用php登录后在主页上进行更改

我已经为我的网页创建了注册和登录页面。问题是，我想在登录后显示用户的姓名和图像，换句话说，我想在登录后在主页上做一些更改。 这是我的代码：
lib.php

 function checkUser($username,$password){
   include "connection.php";
   $result = mysqli_query($conn, "SELECT * FROM `data` WHERE `username` = '$username' AND `password` = '$password'") or die("No result".mysqli_error());

    $row = mysqli_fetch_array($result);
    $logic = false;

    if (($row['username'] == $username) && ($row['password'] == $password)) {
        echo "Login is successfull. Welcome <b>".$row['username']."</b>";
        $logic = true;
    }
    else{
        echo "Failed to login. Username or password is incorrect. Try again.";
    }
    return $logic;  
}
function logIn($username, $password){
    include ("connection.php");
    $_SESSION["loggedInUser"] = $username;
    $_SESSION["loggedInTime"] = time();
}

<?php       
  include "lib.php";

  if(checkUser($username,$password)){
    logIn($username, $password);
    header("Location: index_en.php");//goes to my main page
?>
    <li><a href="#">Hello, <?php echo $username; ?></a></li>
    <script type="text/javascript" src="js/jquery-1.10.2.min.js"></script>
    <script type="text/javascript">
      console.log("successfull");
      $(".nav_header").remove();//I tried to change my index_en.php page, but no changes appear there
    </script>
<?php
    }
?>

<?php
session_start();
if(isset($_SESSION['username'])){
   echo "Hello, ".$_SESSION['username'];
}
?>

函数checkUser（$username，$password）{
包括“connection.php”；
$result=mysqli_query（$conn，“从`data`中选择*，其中`username`='$username'和`password`='$password'））或死（“无结果”.mysqli_error（））；
$row=mysqli\u fetch\u数组（$result）；
$logic=false；
如果（$row['username']=$username）&&（$row['password']=$password））{
echo“登录成功。欢迎”。$row['username']；
$logic=true；
}
否则{
echo“登录失败。用户名或密码不正确。请重试。”；
}
返回$logic；
}
函数登录（$username，$password）{
包括（“connection.php”）；
$\u会话[“loggedInUser”]=$username；
$\会话[“loggedInTime”]=time（）；
}

action.php

<?php       
  include "lib.php";

  if(checkUser($username,$password)){
    logIn($username, $password);
    header("Location: index_en.php");//goes to my main page
?>
    <li><a href="#">Hello, <?php echo $username; ?></a></li>
    <script type="text/javascript" src="js/jquery-1.10.2.min.js"></script>
    <script type="text/javascript">
      console.log("successfull");
      $(".nav_header").remove();//I tried to change my index_en.php page, but no changes appear there
    </script>
<?php
    }
?>

console.log（“成功”）；
$（“.nav_头”）.remove（）//我试图更改我的index_en.php页面，但没有出现任何更改

我理解这个问题，所以我认为您的代码可能是这样的

action.php

 function checkUser($username,$password){
   include "connection.php";
   $result = mysqli_query($conn, "SELECT * FROM `data` WHERE `username` = '$username' AND `password` = '$password'") or die("No result".mysqli_error());

    $row = mysqli_fetch_array($result);
    $logic = false;

    if (($row['username'] == $username) && ($row['password'] == $password)) {
        echo "Login is successfull. Welcome <b>".$row['username']."</b>";
        $logic = true;
    }
    else{
        echo "Failed to login. Username or password is incorrect. Try again.";
    }
    return $logic;  
}
function logIn($username, $password){
    include ("connection.php");
    $_SESSION["loggedInUser"] = $username;
    $_SESSION["loggedInTime"] = time();
}

<?php       
  include "lib.php";

  if(checkUser($username,$password)){
    logIn($username, $password);
    header("Location: index_en.php");//goes to my main page
?>
    <li><a href="#">Hello, <?php echo $username; ?></a></li>
    <script type="text/javascript" src="js/jquery-1.10.2.min.js"></script>
    <script type="text/javascript">
      console.log("successfull");
      $(".nav_header").remove();//I tried to change my index_en.php page, but no changes appear there
    </script>
<?php
    }
?>

<?php
session_start();
if(isset($_SESSION['username'])){
   echo "Hello, ".$_SESSION['username'];
}
?>

console.log（“成功”）；
$（“.nav_头”）.remove（）//我试图更改我的index_en.php页面，但没有出现任何更改

当用户已经登录时，您希望对Index_en.php（主页）进行一些更改，您的页面应该包含，
index_en.php

 function checkUser($username,$password){
   include "connection.php";
   $result = mysqli_query($conn, "SELECT * FROM `data` WHERE `username` = '$username' AND `password` = '$password'") or die("No result".mysqli_error());

    $row = mysqli_fetch_array($result);
    $logic = false;

    if (($row['username'] == $username) && ($row['password'] == $password)) {
        echo "Login is successfull. Welcome <b>".$row['username']."</b>";
        $logic = true;
    }
    else{
        echo "Failed to login. Username or password is incorrect. Try again.";
    }
    return $logic;  
}
function logIn($username, $password){
    include ("connection.php");
    $_SESSION["loggedInUser"] = $username;
    $_SESSION["loggedInTime"] = time();
}

<?php       
  include "lib.php";

  if(checkUser($username,$password)){
    logIn($username, $password);
    header("Location: index_en.php");//goes to my main page
?>
    <li><a href="#">Hello, <?php echo $username; ?></a></li>
    <script type="text/javascript" src="js/jquery-1.10.2.min.js"></script>
    <script type="text/javascript">
      console.log("successfull");
      $(".nav_header").remove();//I tried to change my index_en.php page, but no changes appear there
    </script>
<?php
    }
?>

<?php
session_start();
if(isset($_SESSION['username'])){
   echo "Hello, ".$_SESSION['username'];
}
?>

成功登录后，您将用户重定向到

index_en.php

，使用

header（）重定向将停止其余代码行的执行并重定向您，因此您的“Hello$username”将永远不会显示，console.log（）将永远不会打印到日志。那么，成功登录后会出现什么问题。。只需获取用户详细信息（用户名/配置文件图像）并保留在会话中。如果你想在另一个包含或需要
lib.php
的页面上阅读这些信息，那么你必须在
lib.php
页面上写入。它不会自动传递，仅仅因为你改变了一些变量，如果你想知道的话。此外，登录的内容远不止这些。记住暴力攻击。实际上，您应该从学习AJAX开始。祝你好运。
检查用户（$username，$password）
和
登录（$username，$password）
功能工作正常。我只是没有在那里写完整的代码。问题是在主页内进行更改。为什么action.php中有
header（）
？
header（“Location:index_en.php”）
将页面重定向到index_en.phpSo请记住，
header（）
之后的所有行将不会执行。在注释
header（）
之后，我编写的Hello消息将显示在不在index_en.php内的白色页面上