>在componentDidMountor componentWillMount中添加侦听器

this.subs = [
  this.props.navigation.addListener('didFocus',(payload) => this.componentDidFocus(payload)),];

要么

this.subs = [
  this.props.navigation.addListener('didFocus',this.componentDidFocus),this.props.navigation.addListener('willBlur',this.componentWillBlur),];

然后你可以在componentDidFocus中做任何事情,比如获取数据,更新数据,……
>在componentWillUnmount中,删除侦听器

componentWillUnmount() {
  this.subs.forEach(sub => sub.remove());
}

有关更多详细信息,请参阅此PR：https://github.com/react-navigation/react-navigation/pull/3345

更新：

addListener – Subscribe to updates to navigation lifecycle

React Navigation emits events to screen components that subscribe to
them:

• willBlur – the screen will be unfocused

• willFocus – the screen will focus

• didFocus – the screen focused (if there was a transition,the
  transition completed)

• didBlur – the screen unfocused (if there was a transition,the
  transition completed)

参考：https://reactnavigation.org/docs/en/navigation-prop.html#addlistener-subscribe-to-updates-to-navigation-lifecycle

更新示例：

const didBlurSubscription = this.props.navigation.addListener(
  'didBlur',payload => {
    console.debug('didBlur',payload);
  }
);

JSON有效负载：

{
  action: { type: 'Navigation/COMPLETE_TRANSITION',key: 'StackRouterRoot' },context: 'id-1518521010538-2:Navigation/COMPLETE_TRANSITION_Root',lastState: undefined,state: undefined,type: 'didBlur',};