php重定向无法正常工作

Question

I got a simple redirect on my homepage, which reacts to the user being on a smartphone or tablett. The Class is working and gives back a true when the side is opened on a smartphone.

Therefore if i write an echo in the if-statement it gets echoed. But the redirection doesn't work and i can't make a sense of it. Anyone any clue what i missed here?

include ('includes/Mobiledetecter.php');                 
$detect = new Mobiledetecter;                                  
                                 //
if($detect->isMobile() or $detect->isTablet()) {           
    header('Location: http://www.example.com/');
} 

Answer 1

Exit immediately after setting the header if there is nothing else to do:

if($detect->isMobile() or $detect->isTablet()) {           
    header('Location: http://www.example.com/');
    exit;
} 

Also consider that headers only work if you haven't already sent output to the browser, either explicitly (eg: echo ) or implicitly (eg: by having anything including blank space before the <?php tag that contains this header)

Answer 2

Make sure your code is right at the very top of your Script before any output and also that your opening php tags has no white-space character(s) before it. In essence, your script should look something like this:

<?php // NOTICE THAT THERE IS NO SPACE BEFORE <?php & NO ECHO BEFORE header(...)

    include ('includes/Mobiledetecter.php');                 
    $detect = new Mobiledetecter;                                  
                             //
    if($detect->isMobile() or $detect->isTablet()) {           
        header("Location: http://www.example.com/");
        exit;
    } 

Answer 3

Further to what everyone else is correctly saying that you can't both echo and do a server-side redirect, here's a way to say something and then redirect:

include ('includes/Mobiledetecter.php');                 
$detect = new Mobiledetecter;                                  
                                 //
if($detect->isMobile() or $detect->isTablet()) {           
     echo "Redirecting you to the example website";
     echo "Click <a href='http://www.example.com/'>here</a> if you are not redirected within 5 seconds";        
     echo "<script> setTimeout(function () { window.location.href='http://www.example.com/'; }, 3000);</script>"
     exit;
} 

Answer 4

在标题之前尝试ob_end_clean函数： http ： //php.net/manual/fr/function.ob-end-clean.php