Payroll/backup/App0.js

import React, { Component } from 'react'
import PayrollContract from '../build/contracts/Payroll.json'
import getWeb3 from './utils/getWeb3'

import Common from "./components/Common";
import Accounts from "./components/Accounts";
import Employer from "./components/Employer";
import Employee from "./components/Employee";

import './css/oswald.css'
import './css/open-sans.css'
import './css/pure-min.css'
import './App.css'

class App extends Component {
  constructor(props) {
    super(props)

    this.state = {
      web3: null
    }
  }

  componentWillMount() {
    // Get network provider and web3 instance.
    // See utils/getWeb3 for more info.

    getWeb3.then(results => {
      this.setState({
        web3: results.web3
      })

      // Instantiate contract once web3 provided.
      this.instantiateContract()
    })
    .catch(() => {
      console.log('Error finding web3.')
    })
  }

  instantiateContract() {

    const contract = require('truffle-contract')
    const payroll = contract(PayrollContract)
    payroll.setProvider(this.state.web3.currentProvider)

    // Declaring this for later so we can chain functions on Payroll.
    //var payrollInstance

    // Get accounts.
    this.state.web3.eth.getAccounts((error, accounts) => {

      //console.log(accounts);
      this.setState({
        accounts,
        selectedAccount:accounts && accounts[0]
      });

      payroll.deployed().then((instance) => {
        this.setState({
          payroll:instance
        });
      });

    })
  }

  onSelectAccount=(employee)=>{

    this.setState({
      selectedAccount:employee.target.text
    });

}

  render() {
    //console.log('call render');
    //console.log(this.state);
    const {selectedAccount,accounts,payroll,web3}=this.state;

    if(!accounts){
      return <div>Loading</div>;
    }

    return (
      <div className="App">
        <nav className="navbar pure-menu pure-menu-horizontal">
            <a href="#" className="pure-menu-heading pure-menu-link">Ted智能合约学习Demo</a>
        </nav>

        <main className="container">
          <div className="pure-g">
            <div className="pure-u-1-3">
                <Accounts accounts={accounts} onSelectAccount={this.onSelectAccount} />
            </div>
            <div className="pure-u-2-1">
              {
                selectedAccount === accounts[0]?
                <Employer employer={selectedAccount} payroll={payroll} web3={web3} /> :
                <Employee employee={selectedAccount} payroll={payroll} web3={web3} />
              }
              {
                payroll && <Common account={selectedAccount} payroll={payroll} web3={web3} />
              }
            </div>
          </div>
        </main>
      </div>
    );
  }
}

export default App