我的代码在下面。它工作正常，但我希望在发现错误后不再显示表单。怎么能做到呢？
这是一个单页，用户名验证程序，我只想知道为什么表单之后再次显示，以及我将如何解决它。
<?php require'function.php'; ?>
<?php
$errors = array();
$username = "";
$password = "";
$msg = "Please Log in.";
?>
<?php if (isset($_POST['submit']))
{
$username = $_POST['username'];
$password = $_POST['password'];
if($username != "rish" && $password != "password"){
$msg = "Try again.";
$errors['cred'] = "Wrong Credentials.";
}
}
?>
<!DOCTYPE html>
<html>
<head>
<title>Single Page Form</title>
</head>
<body>
<?php
echo display_error($errors);
?>
<?php echo $msg ?>
<form action="singleform.php" method="post">
Username: <input type="text" name="username" value="<?php echo htmlspecialchars($username); ?>"><br>
Password: <input type="password" name="password" value="<?php echo "" ?>"><br>
<input type="submit" name="submit" value="Submit">
</form>
</body>
</html>
您可以验证 $_POST 数据是否为空。如果不为空，则用户只需加载页面。
可以像下面的代码一样做：
<?php if(empty($_POST)):?>
<form action="singleform.php" method="post">
Username: <input type="text" name="username" value="<?php echo htmlspecialchars($username); ?>"><br>
Password: <input type="password" name="password" value="<?php echo "" ?>"><br>
<input type="submit" name="submit" value="Submit">
</form>
<?php endif;?>
用户是set，，如果错误初始化，则不会显示
<? if (!isset($errors['cred'])) { ?>
<form action="singleform.php" method="post">
Username: <input type="text" name="username" value="<?php echo htmlspecialchars($username); ?>"> <br>
Password: <input type="password" name="password" value="<?php echo "" ?>"><br>
<input type="submit" name="submit" value="Submit">
</form>
<?php } ?>