Question

我正在尝试设计一个系统，如果登录正确，我将使用会话将用户名从 login.php 发送到 upload.php 。每次我尝试时，都会显示一个错误： 注意：未定义的索引：第70行的C：\ xampp \ htdocs \ interface \ upload.php中的用户名 请注意，我已经检查了 upload.php 的第70行，我认为没有任何错误。我的文件上传还可以，但是用户名没有通过会话传输如果您请解释我的代码出了什么问题，那将非常有帮助。 TIA。

db.sql

create database profiles;
use profiles;
create table users
(
id int(10) primary key,
pass varchar(50)
);
create table imageP
(
id int(10),
location varchar(100),
foreign key (id) references users(id)
);
insert into users values(1,'1');

login.php

<?php
session_start();
?>

<!DOCTYPE html>
<html>

<body>
    <form method="post" name="login">
        <input type="number" name="username" placeholder="Enter a Username"/>
        <input type="password" name="password" placeholder="***"/>
        <input type="submit" name="login" value="Login"/>
    </form>
</body>
</html>


<?php
if(isset($_POST['login'])){
    $errmsg_arr = array();
    $errflag = false;

    // configuration
    $dbhost     = "localhost";
    $dbname     = "profiles";
    $dbuser     = "root";
    $dbpass     = "";

    // database connection
    $conn = new PDO("mysql:host=$dbhost;dbname=$dbname",$dbuser,$dbpass);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $conn->exec("SET CHARACTER SET utf8mb4");

    // new data
    $user = $_POST['username'];
    $password = $_POST['password'];
    if($user == '') {
        $errmsg_arr[] = 'You must enter your Username';
        $errflag = true;
    }
    if($password == '') {
        $errmsg_arr[] = 'You must enter your Password';
        $errflag = true;
    }

    // query
    $result = $conn->prepare("SELECT * FROM users WHERE id= :u AND pass= :p");
    $result->bindParam(':u', $user);
    $result->bindParam(':p', $password);
    $result->execute();
    $rows = $result->fetch(PDO::FETCH_NUM);
    if($rows > 0) {
        $_SESSION['username'] = $user;
        header("location: http://localhost/interface/upload.php");
    }
    else{
        $errmsg_arr[] = 'Username and Password are not found';
        echo(errmsg_arr);
        sleep(3);
        header("location: http://localhost/interface/login.php");
        $errflag = true;
    }
}
?>

upload.php

<?php
session_start();
?>

<!DOCTYPE html>
<html>
<body>

<form method="post" enctype="multipart/form-data">
    Select image to upload:
    <input type="file" name="fileToUpload" id="fileToUpload">
    <input type="submit" value="Upload Image" name="submit">
</form>

</body>
</html>

<?php
$username = $_SESSION['username']; // holds url for last page visited.
$target_dir = "uploads/";
$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);
$uploadOk = 1;
$imageFileType = strtolower(pathinfo($target_file,PATHINFO_EXTENSION));

// Check if image file is a actual image or fake image
if(isset($_POST["submit"])) {
    $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
    if($check !== false) {
        echo "File is an image - " . $check["mime"] . ".";
        $uploadOk = 1;
    } else {
        echo "File is not an image.";
        $uploadOk = 0;
    }
}

// Check if file already exists
if (file_exists($target_file)) {
    echo "Sorry, file already exists.";
    $uploadOk = 0;
}

// Check file size
if ($_FILES["fileToUpload"]["size"] > 500000) {
    echo "Sorry, your file is too large.";
    $uploadOk = 0;
}

// Allow certain file formats
if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg"
&& $imageFileType != "gif" ) {
    echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed.";
    $uploadOk = 0;
}

// Check if $uploadOk is set to 0 by an error
if ($uploadOk == 0) {
    echo "Sorry, your file was not uploaded.";
// if everything is ok, try to upload file
} else {
    if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) {
        echo 'hi '.$username;
        echo "The file ". basename( $_FILES["fileToUpload"]["name"]). " has been uploaded.";
    } else {
        echo "Sorry, there was an error uploading your file.";
    }
}
?>

Answer 1

从页面顶部开始会话，并检查session_start（）之前是否没有空格。在任何html代码之前。

Answer 2

在session_start();之后，将login.php放在顶部的DOCTYPE中。然后尝试首先在$_POST

中定义upload.php

$_SESSION['username'] = $_POST['username'];

然后，您现在可以将$_SESSION定义为$username，

$username = $_SESSION['username'];

会话无法从一个php页面转到另一个页面

2 个答案: