受页面保护的 PHP 页面的回显错误

Question

我有一个受保护的页面，需要您登录才能访问页面内容。

我在哪里可以放置一个回显“错误的用户名或错误的密码”的 else 语句

如果用户没有输入准确的用户名/密码？

PHP 页面

<?php
    // Define your username and password 
    $username = "user"; 
    $password = "password"; 
    if ($_POST['txtUsername'] != $username || $_POST['txtPassword'] != $password) { 
?> 
    <h1>Login</h1> 
    <form name="form" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>"> 
        <label>User</label>
        <input type="text" title="Enter your Username" name="txtUsername" />
        <label>Password</label>
        <input type="password" title="Enter your password" name="txtPassword" />
        <input type="submit" name="Submit" value="Login" />
    </form> 
<?php
    } 
    else {
?> 
    <p>This is the protected page. Your private content goes here.</p> 
<?php
    }
?>  

** 我试过在 -- else { 在页面底部之后输入它

** 我试过在 -- if($_POST...$password) {

两者都不起作用。我附上了一张图片来告诉你我的意思。

谢谢

Answer 1

也可以通过简单地设置一些验证标志并在您的视图上使用这些标志来解决。使用您自己的代码结构模板，以下可能会解决问题：

<?php 

// Define your username and password 
$username = "user"; 
$password = "password"; 

$hasError = true;
$hasSubmitted = false;

if (isset($_POST['Submit'])) {
    $hasSubmitted = true;

    if ($_POST['txtUsername'] != $username || $_POST['txtPassword'] != $password) { 
        $hasError = true;
    } else {
        $hasError = false;
    }
}

if ($hasError):
?>
<h1>Login</h1> 

<?php if ($hasSubmitted): ?>
<p>*You entered a wrong username or password</p>
<?php endif; ?>
<form name="form" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>"> 
<label>User</label><input type="text" title="Enter your Username" name="txtUsername" />
<label>Password</label><input type="password" title="Enter your password" name="txtPassword" />
<input type="submit" name="Submit" value="Login" />
</form> 

<?php else: ?>

<p>This is the protected page. Your private content goes here.</p> 

<?php endif; ?>

Answer 2

<?php 
    class   ValidateUser
        {
            public static   function Check($user,$pass)
                {
                    $settings[] =   ($user == $_POST['txtUsername'])? 1:0;
                    $settings[] =   ($pass == $_POST['txtPassword'])? 1:0;

                    return (array_sum($settings) == 2)? true:false;
                }
        }

    // if the username and passowrd match up
    if(isset($_POST['txtUsername'])) {
            $uservalid  = ValidateUser::Check('hardcodeuser','hardcodepass');
        }

    // If user/pass not valid
    if($uservalid !== true || !isset($uservalid)) { ?> 
        <h1>Login</h1> 
        <?php if(isset($uservalid) && $uservalid !== true) echo 'Invalid Login'; ?>
        <form name="form" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>"> 
            <label>User</label>
            <input type="text" title="Enter your Username" name="txtUsername" />
            <label>Password</label><input type="password" title="Enter your password" name="txtPassword" />
            <input type="submit" name="Submit" value="Login" />
        </form> 

<?php } 
    else { ?> 
    <p>This is the protected page. Your private content goes here.</p>
    <?php 
        } ?> 

Answer 3

试试这个并阅读代码中的注释

    <?php 
    if ($_POST['txtUsername'] != $username || $_POST['txtPassword'] != $password) { 

    ?> 

    <h1>Login</h1> 

    <form name="form" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>"> 
    <label>User</label><input type="text" title="Enter your Username" name="txtUsername" />
    <label>Password</label><input type="password" title="Enter your password" name="txtPassword" />
    <input type="submit" name="Submit" value="Login" />
    </form> 

    <?php 

//adde these line to check weather its empty or not    
if(!empty($_POST['txtUsername']) && empty($_POST['txtPassword']))
        {
        //this is complicated part you need check username and password. and they have to 
//match. 
// i cant help you here, cause i dont know from where you want to check username and password
//but i am giving you if statement.
//simple way you get the username from form, than check wether the username password matches, in the db or not, and if does not matches, we show the error message
//run the query
//check the result
//result return succes then ok
//else show the error
        }
        else 
            {
        echo 'You need to enter your username and password';
    }

    } 
    else { 

    ?> 

    <p>This is the protected page. Your private content goes here.</p> 

    <?php 

    }

    ?> 

Answer 4

<?php
// Define your username and password
$username = "user";
$password = "password";

$loginPageTPL = <<< EOF
<!doctype html>
<html>
<head>
<title>Login</title>
</head>
<body>
<h1>Login</h1> 

<form name="form" method="post" action="{% PHP_SELF %}"> 
{% ERROR_MESSAGES %}
<label for="username">User</label>
<input id="username" type="text" placeholder="Enter your Username" name="txtUsername" />
<label for="password">Password</label>
<input id="password" type="password" placeholder="Enter your password" name="txtPassword" />
<input type="submit" name="Submit" value="Login" />
</form> 
</body>
</html>
EOF;

$loginPageTPL = str_replace('{% PHP_SELF %}', $_SERVER['PHP_SELF'], $loginPageTPL);

if ((isset($_POST['txtUsername'])) && (isset($_POST['txtPassword']))) {
    if (($_POST['txtUsername'] == $username) && ($_POST['txtPassword'] == $password)) {
        echo "your private content here";
        return;
    } else {
        $loginPageTPL = str_replace('{% ERROR_MESSAGES %}', '<div style="color: red">* you entered a wrong username and password</div>', $loginPageTPL);
        echo $loginPageTPL;
    }
} else {
    $loginPageTPL = str_replace('{% ERROR_MESSAGES %}', '', $loginPageTPL);
    echo $loginPageTPL;
}