使用react初步实现一个购物车小组件

使用react初步实现一个购物车小组件

下面是完成的状态
在这里插入图片描述

下面是代码

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    table {
    
    
      border: 1px solid #eee;
      border-collapse: collapse;
    }

    th,
    td {
    
    
      border: 1px solid #eee;
      padding: 10px 16px;
      text-align: center;
    }

    th {
    
    
      background: #e5e5e5;
    }
    .count{
    
    
      padding:0 10px;
      vertical-align: middle;
    }
  </style>
</head>

<body>
  <div id="app"></div>
  <!-- 引入依赖  -->
  <script src="../react.development.js"></script>
  <script src="../react-dom.development.js"></script>
  <script src="../babel.min.js"></script>


  <!-- 使用script编写react代码 -->
  <script type="text/babel">
    class App extends React.Component {
    
    
      constructor() {
    
    
        super()
        this.state = {
    
    
          books: [
            {
    
    
              id: 1,
              name: '代码大全1',
              date: '2005-3-19',
              price: 128.00,
              count: 1
            },
            {
    
    
              id: 2,
              name: '代码大全2',
              date: '2005-3-19',
              price: 128.00,
              count: 1
            },
            {
    
    
              id: 3,
              name: '代码大全3',
              date: '2005-3-19',
              price: 128.00,
              count: 1
            },
            {
    
    
              id: 4,
              name: '代码大全4',
              date: '2005-3-19',
              price: 128.00,
              count: 1
            }
          ]
        }
      }
      renderBooks(){
    
    
        return (
          <div>
            <table>
              <thead>
                <tr>
                  <th>序号</th>
                  <th>书籍名称</th>
                  <th>出版日期</th>
                  <th>价格</th>
                  <th>购买数量</th>
                  <th>操作</th></tr>
              </thead>
              <tbody>
                {
    
    this.state.books.map((item,index) => {
    
    
                  return (
                    <tr>
                      <td>{
    
    index + 1}</td>
                      <td>{
    
    item.name}</td>
                      <td>{
    
    item.date}</td>
                      <td>{
    
    item.price}</td>
                      <td>
                        <button disabled={
    
    item.count <=1} onClick={
    
    e=>this.changeCount(index,-1)}>-</button>
                        <span className="count">{
    
    item.count}</span>
                        <button onClick={
    
    e=>this.changeCount(index,+1)}>+</button>
                      </td>
                      <td>
                        <button onClick={
    
    e=>this.remove(index)}>移除</button></td>
                    </tr>
                  )
                })}
              </tbody></table>
              <h2>{
    
    this.state.books.reduce((pre,item)=>{
    
    
                return pre+item.price * item.count},0)}</h2>
          </div>
        )
      }
      renderEmpty(){
    
    
        return <h2>购物车为空</h2> 
            }

      render() {
    
    
        return this.state.books.length?  this.renderBooks() : this.renderEmpty()
      }
      remove(index){
    
    
        this.setState({
    
    
          books: this.state.books.filter((item,indey)=>{
    
    
            return index !=indey
          })
        })
      }
      changeCount(index,count){
    
    
        const arr = [...this.state.books]
        arr[index].count = arr[index].count + count
        this.setState({
    
    
          books: arr
        })

      }
    }
    ReactDOM.render(<App />, document.getElementById("app"))
  </script>
</body>

</html>

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转载自blog.csdn.net/MS6324_ZAKU/article/details/114295363