PHP在全局名称空间中使用类 [英] PHP use class in global namespace

问题描述

我有一个使用PDO的数据库包装器类，并在构造函数中创建了一个PDO对象. wrapper类位于我们的名称空间中，并且正在使用自动加载器.问题在于，在我们的命名空间中找不到PDO类，因此我尝试按照

I have a DB wrapper class that uses PDO and in the constructor I create a PDO object. The wrapper class is in our namespace and we are using an autoloader. The issue is that the PDO class cannot be found within our namespace, so I tried using the global namespace as described here.

//Class file
namespace Company\Common;
class DB {
    private function __construct(){
        $this->Handle=new PDO(...);
    }
}

有了这个，我得到了(如预期的那样):

With this, I get this (as expected):

Warning: require(...\vendors\Company\Common\PDO.class.php): failed to open stream

如果我这样做:

namespace Company\Common;
use PDO;

我明白了:

Fatal error: Class 'DB' not found in ...\includes\utils.php

并且utils.php在错误行中包含此代码，在实现名称空间之前可以正常工作:

And utils.php contains this on the error line, which worked fine before implementing namespaces:

DB::getInstance();

或者我尝试了这个:

namespace Company\Common;
class DB {
    private function __construct(){
        $this->Handle=new \PDO(...);
    }
}

哪个试图像最初那样在我们的命名空间中加载PDO类.

Which tried to load the PDO class within our namespace as it originally did.

我该如何解决?我以为通过执行use PDO或new \PDO它将加载全局PDO类，但是它似乎不起作用?

How can I resolve this? I thought by doing use PDO or new \PDO it would load the global PDO class, but it doesn't seem to be working?

推荐答案

已解决.我没有意识到，别名空间仅适用于当前文件，不适用于将来包含的任何文件.在PHP.net上发现了这一点，它也适用于别名:

Solved it. I didn't realize that aliasing a namespace only applies to the current file, and not any future included files. Found this on PHP.net which also applies to aliasing:

导入规则是基于文件的，这意味着包含的文件将不会继承父文件的导入规则.

Importing rules are per file basis, meaning included files will NOT inherit the parent file's importing rules.

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