Question

我正在尝试访问li上的key={1}元素。我想达到的目的是将activeItem设置为State，以便稍后将其与单击的对象进行比较。我他们是一样的，我想向该元素添加一个活动类。但是我找不到找到传递给我的handleClick函数的键的方法。

感谢您的帮助。

import Link from 'next/link';

class Navbar extends React.Component {

  state = { activeItem: null}

  handleClick = (e) => {


  };

    render() {
    console.log(this.state)
      return (
      <nav className="main-nav">
    <ul>
      <li>
        <a href="/">Home</a>
      </li>
      <li>
        <a href="#">Kategories
          <span className="arrow">&#x25BC;</span>
        </a>
        <ul className="submenu">
          <li 
              onClick={this.handleClick}
              key={1}
          >
              <Link href={`/news?cat=sport`} ><a>Sport</a></Link>
          </li>
          <li>
          <Link href={`/news?cat=health`}><a>Health</a></Link>
          </li>
        </ul>
      </li>

    </ul>
    <style jsx>{`




.main-nav {
    font-family: "Lato";
    font-style: normal;
    font-weight: 400;
    z-index:100;
    -webkit-box-shadow: 1px 3px 23px -8px rgba(0,0,0,0.75);
    -moz-box-shadow: 1px 3px 23px -8px rgba(0,0,0,0.75);
    box-shadow: 1px 3px 23px -8px rgba(0,0,0,0.75);
}
.main-nav a {
    color: #000;
    background: #fff;
    height: 50px;
    font-family: lato;
    font-weight: bold;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    transition: background 0.4s;
  }

  .main-nav a:hover {
    background: #b4d455;
    color: #fff;
    border: 1px solid #000;
  }


  .main-nav a:hover .arrow{
    color: #fff;
    transform: rotate(0);

  }

  .main-nav ul {
    list-style: none;
    display: flex;
  }

  .main-nav li {
    width: 100%;
    text-align: center;
    position: relative;
  }

  .main-nav li:hover .submenu > li {
    display: block;
    flex-direction: column;
    top: 0px;
  }

  .submenu li {
    display: none;
    position: absolute;
    top: 0px;
  }

  .submenu {
    display: flex;
    flex-direction: column;
    position: absolute;
    width: 100%;
  }

  .submenu li {
    position: relative;
  }

  .submenu li:hover .submenu-2 li {
    display: block;
  }


  .arrow {
    margin-left: 8px;
    color: #000;
    font-size: 10px;
    transform: rotate(90deg);
  }

  .active {
    background-color: red;
  }

    `}

    </style>
  </nav>
  );
  }



}

export default Navbar;

谢谢你的回答。有用。但是我不确定这是否是最好的方法。数据键目前不是动态的，我不确定如何在三元组中获取值。

state = { activeItem: null}



  handleClick = e => {

    this.setState({ activeItem : e.currentTarget.dataset.key })
    };

    render() {
      return (
      <nav className="main-nav">
    <ul>
      <li>
        <a href="/">Home</a>
      </li>
      <li>
        <a href="#">Kategories
          <span className="arrow">&#x25BC;</span>
        </a>
        <ul className="submenu">
          <li className={this.state.activeItem == 1 ? 'active' : ''}
              onClick={this.handleClick}
              data-key={1}
          >

Answer 1

如果将其设置为data-key={1}，则可以使用e.currentTarget.dataset进行访问。

如果您这样记录它：

handleClick = e => {
  console.log(e.currentTarget.dataset);
};

您应该得到以下结果：

如何突出显示点击

1 个答案: