取数据后如何用数据初始化state？

Question

import React from 'react';
class Demo extends React.Component{
  constructor(props){
    super(props)
    this.state{
      initData: ''
    }
  }

  render(){
      return(
        <div>{ this.state.initData }<div>
      )
  }
}
function mapStateToProps(state) {
  const { demoData } = state.demo;
  return { demoData };
}
export default connect(mapStateToProps)(Demo );

请问如何使用demoData初始化state呢？用了几个钩子函数都没成功。

Answer 1

用demoData初始化state...啥意思？

Answer 2

componentWillReceiveProps(nextProps){

if(nextProps.demoData  !== this.props.demoData){
    this.setData({
       initData: nextProps.demoData 
    })
}

}