PHP标题（'Content-Type：application / json'）;不管用

Question

对不起，如果是重复的问题，已经尝试过谷歌和StackOverflow中的每一个建议。

出于某种原因，我的响应标题始终为Content-Type：text / html;字符集= UTF-8。

我希望内容类型为json（Content-Type：application / json），不确定我做错了什么。这是我的代码

    <?php
    header('Access-Control-Allow-Origin: *');

    define('__ROOT__', dirname(dirname(__FILE__)));
    require_once(__ROOT__.'/api/csvtojson.php');
    require_once(__ROOT__.'/api/retrieve-login-data.php');
    require_once(__ROOT__.'/api/access-control.php');
    ini_set('display_errors', 1);
    ini_set('display_startup_errors', 1);
    error_reporting(E_ALL);

    //Make sure that it is a POST request.
    if(strcasecmp($_SERVER['REQUEST_METHOD'], 'POST') != 0){
        throw new Exception('Request method must be POST!');
    }

    //Make sure that the content type of the POST request has been set to application/json
    $contentType = isset($_SERVER["CONTENT_TYPE"]) ? trim($_SERVER["CONTENT_TYPE"]) : '';
    if(strcasecmp($contentType, 'application/json') != 0){
        throw new Exception('Content type must be: application/json');
    }

    //Receive the RAW post data.
    $content = trim(file_get_contents("php://input"));

    //Attempt to decode the incoming RAW post data from JSON.
    $decoded = json_decode($content, true);

    //If json_decode failed, the JSON is invalid.
    if(!is_array($decoded)){
        throw new Exception('Received content contained invalid JSON!');
    }
$filename =     $decoded['filename'];

   // open csv file
    if (!($fp = fopen($filename, 'r'))) {
      die("Can't open file...");
      }
    //read csv headers
    $key = fgetcsv($fp,"1024",",");
    // parse csv rows into array
    $json = array();
    while ($row = fgetcsv($fp,"1024",",")) {
      $json[] = array_combine($key, $row);
      }
    // release file handle
    fclose($fp);
    // encode array to json
    header('Content-Type: application/json;charset=utf-8');
    echo (json_encode($json, JSON_PRETTY_PRINT));

响应：

Answer 1

请检查此行之前是否有任何警告：

header('Content-Type: application/json;charset=utf-8');

Answer 2

以这种方式测试：ContentType：“application / x-www-form-urlencoded”