在我的项目中，当有人尝试提交联系人表格时，我尝试重定向到另一页时，我会遇到此类错误，然后应重定向到其他页面，但我遇到了此类错误。错误，这是我得到的
警告：无法修改标头信息-标头已发送 （输出从C：\ xampp \ htdocs \ grade \ header.php：89开始） C：\ xampp \ htdocs \ grade \ contact.php，第64行
header.php
<!DOCTYPE html>
<html lang="en">
<head>
<title>SAMSON SOLAR ENERGY</title>
<!-- Meta tag Keywords -->
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta charset="utf-8">
<meta name="keywords" content="Grade Responsive web template, Bootstrap Web Templates, Flat Web Templates, Android Compatible web template,
Smartphone Compatible web template, free webdesigns for Nokia, Samsung, LG, SonyEricsson, Motorola web design" />
<script type="application/x-javascript">
addEventListener("load", function () {
setTimeout(hideURLbar, 0);
}, false);
function hideURLbar() {
window.scrollTo(0, 1);
}
</script>
<!--// Meta tag Keywords -->
<!-- css files -->
<link rel="stylesheet" href="css/bootstrap.css"> <!-- Bootstrap-Core-CSS -->
<link rel="stylesheet" href="css/style.css" type="text/css" media="all" /> <!-- Style-CSS -->
<link rel="stylesheet" href="css/fontawesome-all.css"> <!-- Font-Awesome-Icons-CSS -->
<!-- //css files -->
<!----->
<link rel="stylesheet" href="css/flexslider.css" type="text/css" media="all" /><!-- for testimonials -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
<!--web font-->
<link href="//fonts.googleapis.com/css?family=Source+Sans+Pro:200,200i,300,300i,400,400i,600,600i,700,700i,900,900i&subset=cyrillic,cyrillic-ext,greek,greek-ext,latin-ext,vietnamese" rel="stylesheet">
<!--//web font-->
</head>
<body>
<!-- header -->
<header>
<div class="container">
<nav class="navbar navbar-expand-lg navbar-light">
<a class="navbar-brand" href="index.html">
<span class="fa fa-strikethrough"></span> SAMSON SOLAR
</a>
<button class="navbar-toggler ml-md-auto" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mx-auto text-center">
<li class="nav-item active mr-lg-3">
<a class="nav-link" href="index.php">Home<span class="sr-only">(current)</span></a>
</li>
<li class="nav-item mr-lg-3">
<a class="nav-link" href="about.php">about</a>
</li>
<li class="nav-item mr-lg-3">
<a class="nav-link" href="gallery.php">Gallery</a>
</li>
<li class="nav-item dropdown mr-lg-3">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Products</a>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<a class="dropdown-item" href="domestic.php">Domestic</a>
<a class="dropdown-item" href="commercial.php">Commercial</a>
<a class="dropdown-item" href="other.php">Other Products</a>
</div>
</li>
<li class="nav-item">
<a class="nav-link" href="contact.php">contact</a>
</li>
</ul>
<div class="buttons">
<p><i class="fas mr-1 fa-phone"></i> +91 99161 67190</p>
</div>
</div>
</nav>
</div>
<div class="icon-bar">
<a href="#" class="facebook"><i class="fa fa-facebook"></i></a>
<a href="#" class="twitter"><i class="fa fa-twitter"></i></a>
<a href="#" class="google"><i class="fa fa-google"></i></a>
<a href="#" class="linkedin"><i class="fa fa-linkedin"></i></a>
<a href="#" class="youtube"><i class="fa fa-youtube"></i></a>
</div>
</header>
<!-- //header -->
contact.php
<?php include 'header.php'; ?>
<!-- banner -->
<section class="inner-banner">
<div class="banner-layer">
<h1 class="text-center">Contact Page</h1>
</div>
</section>
<!-- //banner -->
<?php
include_once 'connect.php';
$nameErr = $emailErr = $contactErr = "";
$name = $email = $contact = $subject = "";
if (isset($_POST['submit']))
{
//Name
if (empty($_POST["name"])) {
$nameErr = "Please enter your Name";
}
else{
$name = test_input($_POST["name"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z ]*$/",$name)) {
$nameErr = "Sorry Only letters are allowed";
}
}
//E-mail ID
if (empty($_POST["email"])) {
$emailErr = "Please enter your E-mail ID";
}
else{
$email = test_input($_POST["email"]);
// check if the entered Email-id is valid or not
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
$emailErr = "Please enter a valid E-mail ID";
}
}
//Contact Number
if (empty($_POST["phone"])) {
$contactErr = "Please enter your Contact Number";
}
else{
$contact = test_input($_POST["phone"]);
// check weather the contact number is valid or not
if (!preg_match("/^[0-9]+$/",$contact)) {
$contactErr = "Please enter Your 10 Digit mobile Number";
}
}
//Reason For contacting
if (!empty($_POST["subject"])) {
$subject = test_input($_POST["subject"]);
}
if($nameErr == "" && $emailErr == "" && $contactErr == ""){
$sql = "INSERT INTO contact(`ID`,`Name`, `Email`, `Contact_no` , `Reason`)
VALUES ('','".$name."', '".$email."', '".$contact."' , '".$subject."')";
if (mysqli_query($mysqli, $sql)) {
header("location:contact_success.php");
exit();
}
else{
echo "Error: " . $sql . "<br>" . mysqli_error($mysqli);
}
mysqli_close($mysqli);
}
}
function test_input($data) {
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
?>
<!-- contact -->
<section class="contact py-5">
<div class="container">
<h2 class="heading mb-lg-5 mb-4">Contact Us</h2>
<div class="row contact-grids w3-agile-grid">
<div class="row col-md-6 col-sm-6 contact-grid1 w3-agile-grid">
<div class="col-3 text-center">
<i class="fa fa-commenting-o" aria-hidden="true"></i>
</div>
<div class="col-9 p-0">
<h4>Get In Touch</h4><br>
<p><b>Mobile:</b> <a href="tel:+91 9916167190">+91 9916167190</a></p>
<p><b>E-mail:</b> <a href="mailto:abpaple@gmail.com">abpaple@gmail.com</a></p>
</div>
</div>
<div class="row col-md-6 col-sm-6 mt-sm-0 mt-4 contact-grid1 w3-agile-grid">
<div class="col-3 text-center">
<i class="fa fa-map-marker" aria-hidden="true"></i>
</div>
<div class="col-9 p-0">
<h4>Visit Our Location</h4><br>
<p><b>SAMSON SOLAR ENERGY</b></p>
<p>#02, K.E.Board Complex, Navalgund Road, Shivaji Circle</p>
<p>DHARWAD-580008, KARNATAKA, INDIA</p>
</div>
</div>
</div><br><br>
<div class="row">
<div class="col-lg-7 col-md-7 col-sm-12 col-xs-12">
<div class="gmap_canvas">
<iframe width="100%" height="475" id="gmap_canvas" src="https://maps.google.com/maps?q=SAMSON%20SOLAR%20ENERGY%20%20%2302%2C%20K.E.Board%20Complex%2C%20Navalgund%20Road%2C%20Shivaji%20Circle%20%20DHARWAD-580008%2C%20KARNATAKA%2C%20INDIA&t=&z=13&ie=UTF8&iwloc=&output=embed" frameborder="0" scrolling="no" marginheight="0" marginwidth="0"></iframe>
</div>
</div>
<div class="col-lg-5 col-md-5 col-sm-12 col-xs-12">
<h2 style="margin-bottom:15px">Write To Us</h2>
<form action="" method="post">
<div class="form-group">
<input type="text" class="form-control" placeholder="Enter Name" name="name" value="<?php if (isset($name)) echo $name; ?>">
<span style="color:red;"> <?php echo $nameErr;?></span>
</div>
<div class="form-group">
<input type="email" class="form-control" placeholder="Enter E-mail" name="email" value="<?php if (isset($email)) echo $email; ?>">
<span style="color:red;"> <?php echo $emailErr;?></span>
</div>
<div class="form-group">
<input type="text" class="form-control" placeholder="Enter Contact Number" name="phone" value="<?php if (isset($contact)) echo $contact; ?>">
<span style="color:red;"> <?php echo $contactErr;?></span>
</div>
<div class="form-group">
<textarea class="form-control" rows="4" placeholder="Enter Reason For Contacting" name="subject"><?php if (isset($subject)) echo $subject; ?></textarea>
</div>
<button type="submit" class="btn btn-primary pull-right" name="submit">Submit</button>
</form>
</div>
</div>
</div>
</section>
<!-- //contact -->
<?php include 'footer.php'; ?>
请任何人可以帮助我解决我的问题
答案 0 :(得分：2)
错误的原因很多：Cannot modify header information - headers already sent如下：
print和echo语句将终止发送HTTP标头的机会<html>在任何header()呼叫之前。<?php之前的空白如果您想详细检查所有原因，那么这里是referenced stackoveflow answer
但是对您而言，此错误的原因是，您之前包含了Raw部分
到<?php代码中，则不能在php代码之前包含html。
在您的代码中，您将包含header.php和html <section>，而在php代码之前，您会收到此错误，因此为了解决此问题，请更改您的
contact.php 文件如下
<?php
include_once 'connect.php';
$nameErr = $emailErr = $contactErr = "";
$name = $email = $contact = $subject = "";
if (isset($_POST['submit']))
{
//Name
if (empty($_POST["name"])) {
$nameErr = "Please enter your Name";
}
else{
$name = test_input($_POST["name"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z ]*$/",$name)) {
$nameErr = "Sorry Only letters are allowed";
}
}
//E-mail ID
if (empty($_POST["email"])) {
$emailErr = "Please enter your E-mail ID";
}
else{
$email = test_input($_POST["email"]);
// check if the entered Email-id is valid or not
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
$emailErr = "Please enter a valid E-mail ID";
}
}
//Contact Number
if (empty($_POST["phone"])) {
$contactErr = "Please enter your Contact Number";
}
else{
$contact = test_input($_POST["phone"]);
// check weather the contact number is valid or not
if (!preg_match("/^[0-9]+$/",$contact)) {
$contactErr = "Please enter Your 10 Digit mobile Number";
}
}
//Reason For contacting
if (!empty($_POST["subject"])) {
$subject = test_input($_POST["subject"]);
}
if($nameErr == "" && $emailErr == "" && $contactErr == ""){
$sql = "INSERT INTO contact(`ID`,`Name`, `Email`, `Contact_no` , `Reason`)
VALUES ('','".$name."', '".$email."', '".$contact."' , '".$subject."')";
if (mysqli_query($mysqli, $sql)) {
header("location:contact_success.php");
exit();
}
else{
echo "Error: " . $sql . "<br>" . mysqli_error($mysqli);
}
mysqli_close($mysqli);
}
}
function test_input($data) {
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
?>
<?php include 'header.php'; ?>
<!-- banner -->
<section class="inner-banner">
<div class="banner-layer">
<h1 class="text-center">Contact Page</h1>
</div>
</section>
<!-- //banner -->
<!-- contact -->
<section class="contact py-5">
<div class="container">
<h2 class="heading mb-lg-5 mb-4">Contact Us</h2>
<div class="row contact-grids w3-agile-grid">
<div class="row col-md-6 col-sm-6 contact-grid1 w3-agile-grid">
<div class="col-3 text-center">
<i class="fa fa-commenting-o" aria-hidden="true"></i>
</div>
<div class="col-9 p-0">
<h4>Get In Touch</h4><br>
<p><b>Mobile:</b> <a href="tel:+91 9916167190">+91 9916167190</a></p>
<p><b>E-mail:</b> <a href="mailto:abpaple@gmail.com">abpaple@gmail.com</a></p>
</div>
</div>
<div class="row col-md-6 col-sm-6 mt-sm-0 mt-4 contact-grid1 w3-agile-grid">
<div class="col-3 text-center">
<i class="fa fa-map-marker" aria-hidden="true"></i>
</div>
<div class="col-9 p-0">
<h4>Visit Our Location</h4><br>
<p><b>SAMSON SOLAR ENERGY</b></p>
<p>#02, K.E.Board Complex, Navalgund Road, Shivaji Circle</p>
<p>DHARWAD-580008, KARNATAKA, INDIA</p>
</div>
</div>
</div><br><br>
<div class="row">
<div class="col-lg-7 col-md-7 col-sm-12 col-xs-12">
<div class="gmap_canvas">
<iframe width="100%" height="475" id="gmap_canvas" src="https://maps.google.com/maps?q=SAMSON%20SOLAR%20ENERGY%20%20%2302%2C%20K.E.Board%20Complex%2C%20Navalgund%20Road%2C%20Shivaji%20Circle%20%20DHARWAD-580008%2C%20KARNATAKA%2C%20INDIA&t=&z=13&ie=UTF8&iwloc=&output=embed" frameborder="0" scrolling="no" marginheight="0" marginwidth="0"></iframe>
</div>
</div>
<div class="col-lg-5 col-md-5 col-sm-12 col-xs-12">
<h2 style="margin-bottom:15px">Write To Us</h2>
<form action="" method="post">
<div class="form-group">
<input type="text" class="form-control" placeholder="Enter Name" name="name" value="<?php if (isset($name)) echo $name; ?>">
<span style="color:red;"> <?php echo $nameErr;?></span>
</div>
<div class="form-group">
<input type="email" class="form-control" placeholder="Enter E-mail" name="email" value="<?php if (isset($email)) echo $email; ?>">
<span style="color:red;"> <?php echo $emailErr;?></span>
</div>
<div class="form-group">
<input type="text" class="form-control" placeholder="Enter Contact Number" name="phone" value="<?php if (isset($contact)) echo $contact; ?>">
<span style="color:red;"> <?php echo $contactErr;?></span>
</div>
<div class="form-group">
<textarea class="form-control" rows="4" placeholder="Enter Reason For Contacting" name="subject"><?php if (isset($subject)) echo $subject; ?></textarea>
</div>
<button type="submit" class="btn btn-primary pull-right" name="submit">Submit</button>
</form>
</div>
</div>
</div>
</section>
<!-- //contact -->
<?php include 'footer.php'; ?>
如果如上所述更改文件后问题仍然存在，请尝试分离html文件contact.php并制作新的php处理文件（如contact_process.php），并仅在contact_process.php中添加php处理代码。
答案 1 :(得分：0)
代替
if (mysqli_query($mysqli, $sql)) {
header("location:contact_success.php");
exit();
}
您可以这样做：
if (mysqli_query($mysqli, $sql)) {
echo "<script>window.location.href = 'contact_success.php';</script>";
exit();
}
可能不是常规的，但应该可以。