React Native 更新组件

Question

我对 react-native 还很陌生。当我单击停止睡眠或信息按钮时，我将补丁请求发送到 users.json 文件以更改 status。我的 JSON 文件包含 ;

{
  "users": [
    {
      "hostname": "XXX.XX.XX.XXX",
      "username": "username",
      "password": "admin",
      "command": "whoami",
      "status": "sleep",
      "info": "temp",
      "id": 1
    }
  ]
}

补丁请求发送成功但是在网页上没有重新加载，我看不到新的status.Here是我的App.js文件；

import React, { Component } from "react";
import AddUser from "./components/AddUser";
import Users from "./components/Users";
import axios from "axios";



const fs = require('fs');
const path = require('path');

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

        this.state = {
            users:[],

          };
      
          this.deleteUser = this.deleteUser.bind(this);
          this.addUser = this.addUser.bind(this);
          this.stopPC = this.stopPC.bind(this);
          this.infoPC = this.infoPC.bind(this) ;
          

    }

    async componentDidMount(){
        const response = await axios.get("http://localhost:3002/users");
       // console.log(response);
       this.setState({users:response.data})
    }

     componentWillUnmount(){
      clearInterval(this.interval);
    } 
    

    async statusUpdate(){
      const response = await axios.get("http://localhost:3002/users");
     // console.log(response);
     this.interval = setInterval(() => this.setState({users:response.data.status}),3000)
  }
   
      //AXIOS API
      deleteUser = async (id) => {
        axios.delete('http://localhost:3002/users/'+ id);
       
        let updatedUsers = this.state.users;
        updatedUsers = updatedUsers.filter(user => user.id !== id);
        
        this.setState({
          users : updatedUsers
        })
    
      }

    
      addUser(newUser){
        
        axios({
          method: 'post',
          url: 'http://localhost:3002/users/',
          data: {
            hostname: newUser.hostname,
            username : newUser.username,
            password: newUser.password,
            command : newUser.command,
            status : newUser.status
          }    
        });

        let updatedUsers = this.state.users;
        updatedUsers.push(newUser);
    
        this.setState({
          users : updatedUsers
        })
    
      }

      stopPC(id){
            axios.patch('http://localhost:3002/users/'+id, {
              command:  'shutdown -s -t 0',
            });    
      }

      sleepPC(id){
          axios.patch('http://localhost:3002/users/'+id, {
            command:  'rundll32.exe user32.dll,LockWorkStation',
            status : 'sleep'
          });    
      }

      infoPC(id){
        axios.patch('http://localhost:3002/users/'+id, {
          command:  'whoami',
          status : 'info'
        });    
    }

   


    render() {
        const title = "Remote Control"
        return (
            <div className="container">
            <h1>{title}</h1>
            <hr/>
            <AddUser addUser= {this.addUser}/>
            <hr/>
            <Users deleteUser= {this.deleteUser} users = {this.state.users} stopPC= {this.stopPC} sleepPC= {this.sleepPC}  infoPC={this.infoPC} statusUpdate={this.statusUpdate} />
      </div>
        );
    }
}

export default App;

这是我的 Users.js 文件；

import React , {Component} from "react";
import User from "./User";
class Users extends Component  {
    render(){
        const {users , deleteUser,stopPC,sleepPC,infoPC} = this.props;
        return(
            <table className="table table-dark">
  <thead>
    <tr>
      <th scope="col">ID</th>
      <th scope="col">Hostname</th>
      <th scope="col">Username</th>
     
      <th scope="col">Stop</th>
      <th scope="col">Sleep</th>
      <th scope="col">Start</th>
      <th scope="col">Status</th>
      <th scope="col">CPU Temperature</th>
      <th scope="col">Info</th>
      <th scope="col">Delete</th>


    </tr>
  </thead>

  <tbody>
            {
                users.map(user => {
                    const {id,hostname,username,password,command,status,info} = user;
                    return <User key={id}
                        id = {id}
                        hostname = {hostname}
                        username = {username}
                        password = {password}
                        command = {command}
                        status={status}
                        info={info}
                        deleteUser = {deleteUser}
                        stopPC={stopPC}
                        sleepPC = {sleepPC}
                        infoPC = {infoPC}
                    />;
                 })
            }
  </tbody>

</table>
        )
    }
}
export default Users;

还有我的 User.js 文件；

import React , {Component} from "react";
import Popup from "./Popup";
const axios = require('axios');
const fs = require('fs');
const path = require('path');


class User extends Component  {

    constructor(props) {
        super(props);
        this.state = {
            buttonPopup: false
        };
      }
   

    onDeleteClick(id,e){
        const {deleteUser} =  this.props;

        deleteUser(id);
        
    }

    onStopClick(id,e){
        const {stopPC} =  this.props;

        stopPC(id);
        
    }

    onSleepClick(id,e){
        const {sleepPC} =  this.props;

        sleepPC(id);
        
    }

    onStartClick(id,e){
        
    }

    buttonPopupfunc(id,e){
        this.setState({buttonPopup : true})
    }

    infofunc(id,e){
        const {infoPC} =  this.props;

        infoPC(id);
    }
   
    render(){
        const {id,hostname,username,status,info,cpuTemp} = this.props;

        return(
            <tr>
                <td>{id}</td>
                <td>{hostname}</td>
                <td>{username}</td>      
                <td><button onClick={() =>{this.onStopClick.bind(this,id);document.location.reload(true)}} className="btn btn-danger">Stop</button></td>
                <td><button onClick={this.onSleepClick.bind(this,id)} className="btn btn-warning">Sleep</button></td>
                <td><button onClick={this.onStartClick.bind(this,id)} className="btn btn-success">Start</button></td>
                <td>{status}</td>
                <td>{cpuTemp}</td>
                <td><button  onClick={() => {this.buttonPopupfunc();this.infofunc(id);}} type="button" class="btn btn-info">&#128712;</button>
                
                <Popup trigger = {this.state.buttonPopup} setTrigger = {() =>this.setState({buttonPopup : false})} >
                <text>{this.infos}</text>
                </Popup>
                
                </td>
            
                <td><button onClick={this.onDeleteClick.bind(this,id)} className="btn btn-danger">Delete</button></td>



            </tr>
            
        )
    }
}

export default User;

我想在网络上看到状态的即时变化page.I 如果你能提供帮助，我会很高兴。这是我的网页；

web page

Answer 1

这里的问题是在后续方法 stopPC、sleepPC 和 infoPC 中补丁请求后状态更改后，您没有更新 users 状态这就是为什么即使状态在服务器上发生了变化，它也没有反映在网页上。

您可以在补丁操作后发送更新的用户对象并用它更新 users 状态：

sleepPC = async (id) => {
  const res = await axios.patch('http://localhost:3002/users/'+id, {
    command:  'rundll32.exe user32.dll,LockWorkStation',
    status : 'sleep'
  );  
  this.setState({ users: res })
}

或者简单地传递一个布尔值，并在前端本身中使用更改后的状态更新用户：

sleepPC = async (id) => {
  const res = await axios.patch('http://localhost:3002/users/'+id, {
    command:  'rundll32.exe user32.dll,LockWorkStation',
    status : 'sleep'
  );  
  if (res) {
    this.setState({
      users: this.state.users.map(user => user.id === id ? { ...user, status: 'sleep' } : user)
    }) 
  }
}

React Native 更新组件

React Native update component

javascript

reactjs

react-native

web