Php重定向到网页（html）

Question

I've seen the use of header in the php to redirect to a page. 我已经看到在php中使用标头重定向到页面。

I've used the method in the code below and the a redirect error as given below the code. 我已经在下面的代码中使用了该方法，并在代码下面给出了重定向错误。

I need to know what went wrong with the code. 我需要知道代码出了什么问题。

Here is the code (php) : 这是代码（php）：

<?php
/**
 * Created by PhpStorm.
 * User: Priyabrata
 * Date: 3/18/14
 * Time: 8:58 PM
 */


function connect_to_db($uid, $pass){
    $con=mysqli_connect("localhost", "root", "12345", "MyDB");
    if (mysqli_connect_errno()){
        echo "Failed to establish link!!";
    }else{
        echo mysqli_connect_error();
    }
    $result=mysqli_query($con, "SELECT `pwd` from `login_table` where `uid` = "."'".$uid."'");
    if (!$result){
        echo "Error!!";
        exit();
    }
    while($xx = mysqli_fetch_array($result)){
        if ($xx['pwd'] == hash("MD5", $pass)){
            header("location:../Html/Login-Existing-Users1_success.htm");
            exit();
        }else{
            echo "Invalid Login Credentials!!";
            exit();
        }
    }
    mysqli_close($con);
}

function validate_credentials(){
    if ((isset($_POST["username"]))&&(isset($_POST["password"]))){
        $uid = $_POST["username"];
        $pwd = $_POST["password"];
        if (($uid == "")||($pwd == "")){
            echo "Please enter User name and password";
        }else{
            //Check user name and password
            connect_to_db($uid, $pwd);
        }
    }else{
        echo "Please enter User name and password";
    }
}

validate_credentials();

Here is the error I get, instead of a redirect when uploaded to the server: 这是我得到的错误，而不是上传到服务器时的重定向：

Warning: Cannot modify header information - headers already sent by (output started at /home/opticfhb/public_html/helpvssupport.net/login.php:19) in /home/opticfhb/public_html/helpvssupport.net/login.php on line 27

Additional Info : This works perfectly in my local machine and creates the problem in the server. 附加信息：这在我的本地计算机上完美运行，并在服务器中创建问题。

Answer 1

You can't call header() after you've already echoed any output. 在您已经回显任何输出后，您不能调用header() 。 HTTP requests contain header information and data. HTTP请求包含标头信息和数据。 Any output is part of the data, and data comes after all the headers have already been sent. 任何输出都是数据的一部分，数据在所有标头都已发送之后出现。

PHP has a function called headers_sent to check whether or not the headers have already been sent or not. PHP有一个名为headers_sent的函数来检查标头是否已经发送过。 You might consider writing a function that issues the Location header if they haven't been, or echo out some simple redirect HTML if they have -- perhaps by including this tag in the <head> : 您可以考虑编写一个函数来发布Location头，如果它们没有，或者回显一些简单的重定向HTML（如果有的话） - 可能通过在<head>包含这个标记：

<meta http-equiv="refresh" content="0;http://www.website.com/redirect/url" />

Php重定向到网页（html）

问题描述

1 个解决方案

解决方案1
2 已采纳 2014-03-22 16:51:41

Php重定向到网页（html）

问题描述

1 个解决方案

解决方案1 2 已采纳 2014-03-22 16:51:41

解决方案1
2 已采纳 2014-03-22 16:51:41