React实现轮播效果

时间:2022-09-20 21:07:17

本文实例为大家分享了React实现轮播,供大家参考,具体内容如下

思路

1、使用全局的state进行状态管理
2、设置全局下标,对当前的图片下表进行样式划分
3、定时循环人物便利改变全局下标 

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<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <style>
    ul{
      width: 100%;
      text-align: center;
      list-style-type: circle;
    }
    ul>li{
      width: 2%;
      float: left;
    }
    img{
      width: 100%;
    }
    </style>
  <title>轮播事件</title>
</head>
<body>
  <div id="root" style="max-width: 700px;margin: 0 auto;"></div>
</body>
 
<script src="./js/react.development.js"></script>
<script src="./js/react-dom.development.js"></script>
<script src="./js/babel.min.js"></script>
<script type="text/babel">
  window.onload=()=>{
    class Img extends React.Component{
      constructor(props) {
        super(props);
        this.state={
          listImg:[
            './img/banner1.jpg',
            './img/banner2.jpg',
            './img/banner3.jpg',
            './img/banner4.jpg',
            './img/banner5.jpg',
          ],
          index:0
        }
      }
      //计时器执行
      indexChange(){
        if(this.state.index == this.state.listImg.length-1){
          this.setState({
            index:0
          })
        }else{
          // this.state.index++;
          this.setState({
            index:this.state.index+1
          })
          console.log(this.state.index);
        }
      }
      componentDidMount(){
        setInterval(()=>{
          this.indexChange();
        },2000)
      }
      render(){
        let {listImg,index} = this.state;
        let imgList=listImg.map((item,imgIndex)=>{
          return <img src={item} key={imgIndex} style={{'display':index == imgIndex ? 'block' : 'none'}} className='img'/> 
        })
        let liList=listImg.map((item2,imgIndex2)=>{
          return <li key={imgIndex2} style={{'listStyleType':index == imgIndex2 ? 'initial' :'circle'}}></li>
        })
        return (
          <div>
              {imgList}
            <div>
              <ul>
                {liList}
              </ul>
            </div>
          </div>
        )
      
      }
    }
    
    ReactDOM.render(
      <Img />,
      document.getElementById("root")
    )
  }
 
</script>
</html>

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。 

原文链接:https://blog.csdn.net/qq_38880700/article/details/94448107