找不到带有 PHP 命名空间的类

2022-01-14 00:00:00 namespaces php

我之前发布了一些关于在 PHP 中使用命名空间的问题，从我得到的信息来看，我下面的示例代码应该可以工作.

I posted some questions previously regarding the use of Namespaces in PHP and from what I got, this example code I have below should be working.

但是，当我尝试像这样在 PHP 中使用命名空间时出现错误.这是按原样运行下面的代码时的第一个错误...

However I am getting errors when I try to use Namespace in PHP like this. Here is the first error when running the code below as is... 

Fatal error: Class 'Controller' not found in E:Controllers	esting.php on line 6

E:Controller esting.php 文件

E:Controller esting.php File

<?php
use Controller;

include('testcontroller.php');

$controller = new Controller;
$controller->show();
?>

E:Controller estcontroller.php 文件

E:Controller estcontroller.php File

<?php
use LibraryRegistry;

namespace Controller
{
    class Controller
    {
        public $registry;

        function __construct()
        {
            include('E:LibraryRegistry.class.php');
            $this->registry = new Registry;
        }

        function show()
        {
            echo $this->registry;
            echo '<br>Registry was ran inside testcontroller.php<br>';
        }
    }
}
?>

E:LibraryRegistry.class.php 文件

E:LibraryRegistry.class.php File

<?php
namespace LibraryRegistry
{
    class Registry
    {
        function __construct()
        {
            return 'Registry.class.php Constructor was ran';
        }
    }
}
?>

如您所见，我试图使其尽可能简单，只是为了让命名空间部分正常工作.我尝试了不同的变体，但似乎无法弄清楚.

As you can see I tried to make it as simple as possible just to get the Namespace part working. I have tried different variations and cannot seem to figure it out.

推荐答案

即使使用 use 语句，您也需要指定您尝试实例化的类的命名空间.这里有很多例子:http://www.php.net/manual/en/language.namespaces.importing.php

Even when using use statement, you need to specify the namespace of the class you are trying to instantiate. There are a lot of examples here: http://www.php.net/manual/en/language.namespaces.importing.php

为了更好地理解它，我将向您描述它是如何工作的.在您的情况下，当您执行 use Controller 时，整个 Controller 命名空间对您可用，但此命名空间中的类不可用.所以，例如:

To understand it better, I will describe to you how it works. In your case, when you do use Controller, the whole Controller namespace becomes available to you, but not the classes that are in this namespace. So, for example:

<?php
include('testcontroller.php');

use Controller;

// Desired class is in namespace!
$controller = new ControllerController();

// Error, because in current scope there is no such class
$controller = new Controller();

$controller->show();
?>

另一个例子:

testcontoller.php:

testcontoller.php:

<?php
namespace SomePathToController;

class Controller
{
    function __construct()
    {

    }

    function show()
    {
        echo '<br>Was run inside testcontroller.php<br>';
    }
}
?>

testing.php:

testing.php:

<?php
include('testcontroller.php');

use SomePathToController;

// We now can access Controller using only Controller namespace,
// not SomePathToController
$controller = new ControllerController();

// Error, because, again, in current scope there is no such class
$controller = new Controller();

$controller->show();
?>

如果您希望准确导入 Controller class，您需要执行 use ControllerController - 然后可以在您当前的范围.

If you wish to import exactly the Controller class, you need to do use ControllerController - then this class will be accessible in your current scope.

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