javascript - 使用 React 向表中添加条目

Question

按下提交按钮后，信息应与之前输入的所有信息一起显示在下面的列表中（自动按姓氏排序）。这样，应用程序就可以用作简单的电话簿。

这就是我现在所拥有的。我需要在相应部分下显示从输入到表格的输入值 -

import React, { useState } from 'react';
import ReactDOM from 'react-dom';

const style = {
  table: {
    borderCollapse: 'collapse'
  },
  tableCell: {
    border: '1px solid gray',
    margin: 0,
    padding: '5px 10px',
    width: 'max-content',
    minWidth: '150px'
  },
  form: {
    container: {
      padding: '20px',
      border: '1px solid #F0F8FF',
      borderRadius: '15px',
      width: 'max-content',
      marginBottom: '40px'
    },
    inputs: {
      marginBottom: '5px'
    },
    submitBtn: {
      marginTop: '10px',
      padding: '10px 15px',
      border:'none',
      backgroundColor: 'lightseagreen',
      fontSize: '14px',
      borderRadius: '5px'
    }
  }
}

function PhoneBookForm({ addEntryToPhoneBook }) {
  return (
    <form onSubmit={e => { e.preventDefault() }} style={style.form.container}>
      <label>First name:</label>
      <br />
      <input 
        style={style.form.inputs}
        className='userFirstname'
        name='userFirstname' 
        type='text'
      />
      <br/>
      <label>Last name:</label>
      <br />
      <input 
        style={style.form.inputs}
        className='userLastname'
        name='userLastname' 
        type='text' 
      />
      <br />
      <label>Phone:</label>
      <br />
      <input
        style={style.form.inputs}
        className='userPhone' 
        name='userPhone' 
        type='text'
      />
      <br/>
      <input 
        style={style.form.submitBtn} 
        className='submitButton'
        type='submit' 
        value='Add User' 
      />
    </form>
  )
}

function InformationTable(props) {
  return (
    <table style={style.table} className='informationTable'>
      <thead> 
        <tr>
          <th style={style.tableCell}>First name</th>
          <th style={style.tableCell}>Last name</th>
          <th style={style.tableCell}>Phone</th>
        </tr>
      </thead> 
    </table>
  );
}

function Application(props) {
  return (
    <section>
      <PhoneBookForm />
      <InformationTable />
    </section>
  );
}

ReactDOM.render(
  <Application />,
  document.getElementById('root')
);

标签： javascriptreactjsreact-hooks

Answer 1

const { useState, useRef } = React

const style = {
  table: {
    borderCollapse: 'collapse'
  },
  tableCell: {
    border: '1px solid gray',
    margin: 0,
    padding: '5px 10px',
    width: 'max-content',
    minWidth: '150px'
  },
  form: {
    container: {
      padding: '20px',
      border: '1px solid #F0F8FF',
      borderRadius: '15px',
      width: 'max-content',
      marginBottom: '40px'
    },
    inputs: {
      marginBottom: '5px'
    },
    submitBtn: {
      marginTop: '10px',
      padding: '10px 15px',
      border:'none',
      backgroundColor: 'lightseagreen',
      fontSize: '14px',
      borderRadius: '5px'
    }
  }
}


function PhoneBookForm({ addEntryToPhoneBook }) {
  const name = useRef(null);
  const lastName = useRef(null);
  const phone = useRef(null);

  return (
    <form onSubmit={e => {
      e.preventDefault();
      console.log("pozzo");
      addEntryToPhoneBook(prev => ([...prev, { userFirstName: name.current.value, userLastName: lastName.current.value, userPhone: phone.current.value }]))
    }} style={style.form.container}>
      <label>First name:</label>
      <br />
      <input 
        style={style.form.inputs}
        className='userFirstname'
        name='userFirstname'
        ref={name}
        type='text'
      />
      <br/>
      <label>Last name:</label>
      <br />
      <input 
        style={style.form.inputs}
        className='userLastname'
        name='userLastname'
        ref={lastName}
        type='text' 
      />
      <br />
      <label>Phone:</label>
      <br />
      <input
        style={style.form.inputs}
        className='userPhone' 
        name='userPhone'
        ref={phone}
        type='text'
      />
      <br/>
      <input 
        style={style.form.submitBtn} 
        className='submitButton'
        type='submit' 
        value='Add User' 
      />
    </form>
  )
}

function InformationTable({ phoneBook }) {
  return (
    <table style={style.table} className='informationTable'>
      <thead> 
        <tr>
          <th style={style.tableCell}>First name</th>
          <th style={style.tableCell}>Last name</th>
          <th style={style.tableCell}>Phone</th>
        </tr>
      </thead>
       <tbody>
        {phoneBook.map(el => (
           <tr>
              <td>{el.userFirstName}</td>
              <td>{el.userLastName}</td>
              <td>{el.userPhone}</td>
           </tr>
        ))}
      </tbody>
    </table>
  );
}

function Application(props) {
  const [book, setBook] = useState([{ userFirstName: "toto", userLastName: "tozzi", userPhone: "0982798736" }]);
  
  return (
    <section>
      <PhoneBookForm addEntryToPhoneBook={setBook} />
      <InformationTable phoneBook={book} />
    </section>
  );
}

ReactDOM.render(
  <Application />,
  document.getElementById('test')
);

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.8.0/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.8.0/umd/react-dom.production.min.js"></script>
<div id="test"></div>

您需要使用在 PhoneBookForm 和 InformationTable 之间共享的状态：

  const [book, setBook] = useState([]) // empty array for initialization

  return (
    <section>
      <PhoneBookForm addToPhoneBook={setBook} /> 
      <InformationTable phoneBook={book} />
    </section>
  );

然后在 PhoneBookForm 中，您将在 onSubmit 期间添加状态内的所有信息：

function PhoneBookForm({ addToPhoneBook }) {
  return (
    <form onSubmit={e => {
       e.preventDefault();
       addToPhoneBook((prev) => [...prev, { userFirstName: ........ }]);
       // here I used a function inside the setState to get access to the previous value of
       // the state, if you're not confortable with this i encourage you to look at spread
       // operator and the doc of useState
    }} style={style.form.container}>
      {...}
    </form>
  )
}

最后，您可以使用图书道具上的地图功能构建您的表格：

function InformationTable({ phoneBook }) {
  return (
    <table style={style.table} className='informationTable'>
      <thead> 
        <tr>
          <th style={style.tableCell}>First name</th>
          <th style={style.tableCell}>Last name</th>
          <th style={style.tableCell}>Phone</th>
        </tr>
      </thead>
      <tbody>
        {phoneBook.map(el => (
           <tr>
              <td>{el.userFirstName}</td>
              <td>{el.userLastName}</td>
              <td>{el.userPhone}</td>
           </tr>
        )}
      </tbody>
    </table>
  );
}