小编use*_*067的帖子

我一直在React js编码.我已经读过在ES6课程中访问'this'我们需要先调用super(道具),我想知道为什么这是.答案我发现主要是谈论Javascript无法知道'这'是什么,除非超类叫做.我想知道这是什么意思,因为在构造函数之外,'this'被识别,我们每次都不调用super(props).

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = { /* initial state */ };
  }
}

 HelloWorld obj = (HelloWorld) context.getBean("helloWorld");
  obj.getMessage();
  context.registerShutdownHook();  

输出下方:

Feb 03, 2017 11:46:12 AM org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh  
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@799f7e29: startup date [Fri Feb 03 11:46:12 IST 2017]; root of context hierarchy
Feb 03, 2017 11:46:12 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions  
INFO: Loading XML bean definitions from class path resource [Beans.xml]
Bean is going through init.  
Your Message : Hello World!  
Bean will destroy now.  

而使用context.close()给予

Feb 03, 2017 11:53:57 AM org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh  
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@799f7e29: startup date [Fri Feb 03 11:53:57 …