import React, { Component } from 'react';

export default class Main extends Component {
 //構(gòu)造函數(shù)
  constructor(props) {
    super(props);
    console.log("constructor");
    //初始化狀態(tài)值
    this.state = {message: "helloworld"}
  }
 
  //準(zhǔn)備加載組件
  componentWillMount() {
    console.log("componentWillMount");
  }
 
  //渲染界面
  render() {
    console.log("render");
    return (
      <div style={styles.container}>
        <p style={styles.info}>
          {this.state.message}
        </p>
      </div>
    );
  }
 
  //組件加載成功并渲染出來(lái)
  componentDidMount() {
    console.log("componentDidMount");
  }
 
  //組件接收到新的 props 時(shí)觸發(fā)
  componentWillReceiveProps(nextProps) {
    console.log("componentWillReceiveProps");
  }
 
  //決定是否需要更新組件
  shouldComponentUpdate(nextProps, nextState) {
    console.log("shouldComponentUpdate");
  }
 
  //組件重新渲染前會(huì)調(diào)用
  componentWillUpdate(nextProps, nextState) {
    console.log("componentWillUpdate");
  }
 
  //組件重新渲染后會(huì)調(diào)用
  componentDidUpdate(prevProps, prevState) {
    console.log("componentDidUpdate");
  }
 
  //組件被卸載前會(huì)調(diào)用
  componentWillUnmount() {
    console.log("componentWillUnmount");
  }
}
 
const styles = StyleSheet.create({
  container:{
     flex:1,
     marginTop:40,
     alignItems:'center',
  },
  info:{
    fontSize:20,
  },
});
 
AppRegistry.registerComponent('HelloWorld', () => Main);