PHP中的名称空间和set_include_path（）有问题

C:\xampp\htdocs包含Controller.php和ApplicationHelper.php。C:\xampp\htdocs\site包含index.php

以下是我得到的错误：

致命错误：在第17行的C:\xampp\htdocs\controller.php中找不到类“site\controller\ApplicationHelper”

我对整个名称空间业务都是新手，但我不能100%肯定这就是它背后的原因。尽管我将include路径设置为在该文件夹中查找，但它似乎没有找到ApplicationHelper.php。如果我在Controller.php中直接包含ApplicationHelper.php，它就会工作。以下是（相关）代码：

index.php

set_include_path(get_include_path() . PATH_SEPARATOR . 'C:\xampp\htdocs');

require('Controller.php');
\site\controller\Controller::run();

namespace site\controller;

class Controller {

    private $applicationHelper;
    private function __construct () {}

    static function run () {
        $instance = new Controller();
        $instance->init();
    }

    function init () {
        $applicationHelper = ApplicationHelper::instance();
        $applicationHelper->init();
    }

}

namespace site\controller;

class ApplicationHelper {

    private static $instance;

    private function __construct () {}

    static function instance () {
        if (!self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    function init() {

    }

}

Controller.php

set_include_path(get_include_path() . PATH_SEPARATOR . 'C:\xampp\htdocs');

require('Controller.php');
\site\controller\Controller::run();

namespace site\controller;

class Controller {

    private $applicationHelper;
    private function __construct () {}

    static function run () {
        $instance = new Controller();
        $instance->init();
    }

    function init () {
        $applicationHelper = ApplicationHelper::instance();
        $applicationHelper->init();
    }

}

namespace site\controller;

class ApplicationHelper {

    private static $instance;

    private function __construct () {}

    static function instance () {
        if (!self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    function init() {

    }

}

ApplicationHelper.php

set_include_path(get_include_path() . PATH_SEPARATOR . 'C:\xampp\htdocs');

require('Controller.php');
\site\controller\Controller::run();

namespace site\controller;

class Controller {

    private $applicationHelper;
    private function __construct () {}

    static function run () {
        $instance = new Controller();
        $instance->init();
    }

    function init () {
        $applicationHelper = ApplicationHelper::instance();
        $applicationHelper->init();
    }

}

namespace site\controller;

class ApplicationHelper {

    private static $instance;

    private function __construct () {}

    static function instance () {
        if (!self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    function init() {

    }

}

---

谢谢你的帮助

您需要包括ApplicationHelper.php或使用自动加载器

function __autoloader($class_name)
{
    include  $class_name . "php";
}

---

请看以下内容：

谢谢。我现在明白了。是把它放在index.php中还是放在每个使用它的类中？