如果我们不能正确理解CORS的功能，它会成为一个令人头痛的问题。我在PHP中使用它们，它们工作起来没有问题。参考这里

header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Credentials: true");
header("Access-Control-Max-Age: 1000");
header("Access-Control-Allow-Headers: X-Requested-With, Content-Type, Origin, Cache-Control, Pragma, Authorization, Accept, Accept-Encoding");
header("Access-Control-Allow-Methods: PUT, POST, GET, OPTIONS, DELETE");

许多互联网范围内的描述没有提到指定Access-Control-Allow-Origin是不够的。下面是一个适合我的完整例子:

<?php
    if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
        header('Access-Control-Allow-Origin: *');
        header('Access-Control-Allow-Methods: POST, GET, DELETE, PUT, PATCH, OPTIONS');
        header('Access-Control-Allow-Headers: token, Content-Type');
        header('Access-Control-Max-Age: 1728000');
        header('Content-Length: 0');
        header('Content-Type: text/plain');
        die();
    }

    header('Access-Control-Allow-Origin: *');
    header('Content-Type: application/json');

    $ret = [
        'result' => 'OK',
    ];
    print json_encode($ret);

我使用这5个头，之后解决了cors错误(后端:PHP，前端:VUE JS)

header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, PUT, POST, DELETE, OPTIONS, post, get');
header("Access-Control-Max-Age", "3600");
header('Access-Control-Allow-Headers: Origin, Content-Type, X-Auth-Token');
header("Access-Control-Allow-Credentials", "true");

我只是设法让dropzone和其他插件与此修复工作(angularjs + php后端)

 header('Access-Control-Allow-Origin: *'); 
    header("Access-Control-Allow-Credentials: true");
    header('Access-Control-Allow-Methods: GET, PUT, POST, DELETE, OPTIONS');
    header('Access-Control-Max-Age: 1000');
    header('Access-Control-Allow-Headers: Origin, Content-Type, X-Auth-Token , Authorization');

将此添加到您的upload.php或发送请求的地方(例如，如果您有upload.html，您需要将文件附加到upload.php，然后复制并粘贴这4行)。 此外，如果你在chrome/mozilla中使用CORS插件/插件，请确保切换它们不止一次，以便启用CORS

如果我们不能正确理解CORS的功能，它会成为一个令人头痛的问题。我在PHP中使用它们，它们工作起来没有问题。参考这里

header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Credentials: true");
header("Access-Control-Max-Age: 1000");
header("Access-Control-Allow-Headers: X-Requested-With, Content-Type, Origin, Cache-Control, Pragma, Authorization, Accept, Accept-Encoding");
header("Access-Control-Allow-Methods: PUT, POST, GET, OPTIONS, DELETE");

这应该可以

header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Headers: X-Requested-With, Content-Type, Origin, Cache-Control, Pragma, Authorization, Accept, Accept-Encoding");