从实例调用静态函数 [英] Calling static function from instance

问题描述

我正在尝试从其子类的成员中调用静态魔术函数(__callStatic).问题是，它转到非静态__call.

I'm trying to call a static magic function (__callStatic) from a member of its child class. Problem being, it goes to the non-static __call instead.

<?php

ini_set("display_errors", true);

class a
{
    function __call($method, $params)
    {
        echo "instance";
    }

    static function __callStatic($method, $params)
    {
        echo "static";
    }
}

class b extends a
{
    function foo()
    {
        echo static::bar();
        // === echo self::bar();
        // === echo a::bar();
        // === echo b::bar();
    }
}

$b = new b();
echo phpversion()."<br />";
$b->foo();

?>

输出:

5.3.6
instance

如何使其显示为静态"?

How can I make it display "static"?

推荐答案

如果删除魔术方法'__call'，代码将返回'static'.

If you remove the magic method '__call', your code will return 'static'.

根据 http://php.net/manual/en/language. oop5.overloading.php 在静态上下文中调用不可访问的方法时，会触发__callStatic()".

According to http://php.net/manual/en/language.oop5.overloading.php "__callStatic() is triggered when invoking inaccessible methods in a static context".

我认为您的代码中正在发生的事情，

What I think is happening in your code is that,

1. 您正在从非静态上下文中调用静态方法.
2. 方法调用处于非静态上下文中，因此PHP搜索魔术方法'__call'.
3. PHP会触发魔术方法'_ call'(如果存在).或者，如果不存在，它将调用" _callStatic".

1. You are calling static method from a non-static context.
2. The method call is in non-static context, so PHP searches for the magic method '__call'.
3. PHP triggers the magic method '_call' if it's exists. Or, if it's not exists it will call '_callStatic'.

这是一个可能的解决方案:

class a
{
    static function __callStatic($method, $params)
    {
        $methodList =  array('staticMethod1', 'staticMethod2');

        // check if the method name should be called statically
        if (!in_array($method, $methodList)) {
            return false;
        }

        echo "static";

        return true;
    }

    function __call($method, $params)
    {
         $status = self::__callStatic($method, $params);
         if ($status) {
             return;
         }
         echo "instance";
    }

}

class b extends a
{
    function foo()
    {
        echo static::staticMethod1();
    }

    function foo2()
    {
        echo static::bar();
    }
}

$b = new b();
echo phpversion()."<br />";
$b->foo();
$b->foo2();

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