如何使用类方法作为回调

问题描述

我有一个包含要用作回调的方法的类。 如何将它们作为参数传递？

Class MyClass {
    
    public function myMethod() {
        // How should these be called?
        $this->processSomething(this->myCallback);
        $this->processSomething(self::myStaticCallback);
    }

    private function processSomething(callable $callback) {
        // Process something...
        $callback();
    }

    private function myCallback() {
        // Do something...
    }

    private static function myStaticCallback() {
        // Do something...
    }   
    
}

推荐答案

查看callable manual以查看将函数作为回调传递的所有不同方式。我在这里复制了该手册，并根据您的方案添加了每种方法的一些示例。

可调用

  // Not applicable in your scenario
  $this->processSomething('some_global_php_function');

  // Only from inside the same class
  $this->processSomething([$this, 'myCallback']);
  $this->processSomething([$this, 'myStaticCallback']);
  // From either inside or outside the same class
  $myObject->processSomething([new MyClass(), 'myCallback']);
  $myObject->processSomething([new MyClass(), 'myStaticCallback']);

  // Only from inside the same class
  $this->processSomething([__CLASS__, 'myStaticCallback']);
  // From either inside or outside the same class
  $myObject->processSomething(['NamespaceMyClass', 'myStaticCallback']);
  $myObject->processSomething(['NamespaceMyClass::myStaticCallback']); // PHP 5.2.3+
  $myObject->processSomething([MyClass::class, 'myStaticCallback']); // PHP 5.5.0+

  // Not applicable in your scenario unless you modify the structure
  $this->processSomething(function() {
      // process something directly here...
  });