如何初始化我的反应本机状态？

Question

I'm wondering how to init my state in that case : Basicaly, I want to get data from AsyncStorage and write it to my screen as a list.

export class History_d extends Component {

constructor(props){
  super(props)
  this.state = {
    stores : ???????????
  }
}

componentDidMount() {
  AsyncStorage.getAllKeys((err, keys) => {
    AsyncStorage.multiGet(keys, (err, stores) => {
      this.setState({ stores });
    });
  });
}

render() {
  return (
    <View>
      {this.state.stores.length && this.state.stores.map(item =>
        <Text>{item[0]} {item[1]}</Text>)}
    </View>
  )
}
}

Can someone explain me what I should write in my constructor to init my state ?

Thank you !

Answer 1

You can set it to null in constructor and in redner have something like:

if (!this.state.stores)
    return <Text>Loading...</Text>;

Bonus: You can set initial state without writing constructor:

export class History_d extends Component {
    state = {stores: null}

    ...