小编Kim*_*kim的帖子

嗨,我对React很新,并且非常难以绕过整个状态管理并通过状态和道具传递数据.我确实理解标准的反应方式是以单向方式传递数据 - 从父节点到子节点,我已经为所有其他组件这样做了.但我有一个名为Book的组件,它根据用户选择形式'read,wantToRead,currentReading和none'改变其"shelf"状态.在我的BookList组件中呈现Book组件,但它需要能够读取Book的架子状态并在名为'read,wantToRead,currentReading和none'的部分下呈现正确的书籍.而且由于在这种情况下,Book组件是从BookList组件呈现的,而BookList是父组件,我真的无法理解如何启用BookList来访问Book的状态？BookList组件:

import React, { Component } from 'react'
import { Link } from 'react-router-dom'

import Book from './Book'

class BookList extends Component {
  render(){
    const { books, shelf } = this.props


    return (
    <div className="list-books">
      <div className="list-books-content">
        <div className="list-books-title">
          <h1>MyReads</h1>
        </div>

        <div className="bookshelf">
          <h2 className="bookshelf-title">None</h2>
          {books.map((book)=> {
            console.log(book)
            if (shelf === ''){
              return <div className="bookshelf-books">
                    {/* <BookStateless book= {book} /> */}
                    <Book book = {book} />
                      {/* <BookStateless book= {book} /> */}
                    </div>

            }
          })}
        </div>


        <div className="bookshelf"> …

我正在使用 jquery 使用户能够单击按钮来复制折扣代码。由于某种原因，document.execCommand("Copy");根本不起作用。当我ctrl + v粘贴时，什么也没有复制过来。有人可以帮我吗？谢谢！！

$(document).ready(function(){
$('#copyBtn').click(function(){

  console.log("loaded")
  var copyText = $('#discountCode');
  console.log($('#discountCode').text())
  copyText.select();
  document.execCommand("Copy");
  alert("Copied the text: " + copyText.text());
})

});

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