Question

我正在编写一个音乐播放器应用程序，但是遇到了麻烦。我正在尝试一种方法：

•当我将鼠标悬停在歌曲上时，它会显示一个“播放”按钮来代替歌曲编号。

•当前正在播放的歌曲在歌曲编号的位置显示一个“暂停”按钮。

•暂停的歌曲显示一个“播放”按钮来代替歌曲编号。

我想在此方法中使用onMouseEnter和onMouseLeave事件，但我不知道从哪里开始

这是我的相册组件

import React, { Component } from 'react';
import albumData from './../data/albums';

class Album extends Component {
    constructor(props) {
          super(props);

        const album = albumData.find( album => {
          return album.slug === this.props.match.params.slug
        });

        this.state = {
          album: album,
            currentSong: album.songs[0],
            isPlaying: false
        };

        this.audioElement = document.createElement('audio');
        this.audioElement.src = album.songs[0].audioSrc;
        }

        play() {
              this.audioElement.play();
              this.setState({ isPlaying: true });
            }

        pause() {
              this.audioElement.pause();
              this.setState({ isPlaying: false });
            }   

        setSong(song) {
              this.audioElement.src = song.audioSrc;
              this.setState({ currentSong: song });
            }

        handleSongClick(song) {
              const isSameSong = this.state.currentSong === song;
              if (this.state.isPlaying && isSameSong) {
                   this.pause();
                 } else {
                   if (!isSameSong) { this.setSong(song); }     
                   this.play();
                 }  
            }



    render() {
      return (
         <section className="album">
            <section id="album-info">
                 <img id="album-cover-art" src={this.state.album.albumCover} alt={this.state.album.title}/>
                 <div className="album-details">
                 <h1 id="album-title">{this.state.album.title}</h1>
                 <h2 className="artist">{this.state.album.artist}</h2>
                 <div id="release-info">{this.state.album.releaseInfo}</div>
              </div>
            </section>
            <table id="song-list">
                <colgroup>
                    <col id="song-number-column" />
                    <col id="song-title-column" />
                    <col id="song-duration-column" />
                </colgroup>  
                <tbody>
                {this.state.album.songs.map( (song, index) =>
                    <tr className="song" key={index} onClick={() => this.handleSongClick(song)} >
                          <td className="song-actions">
                             <button>
                                <span className="song-number">{index+1}</span>
                                <span className="ion-play"></span>
                                <span className="ion-pause"></span>
                            </button>
                          </td>
                          <td className="song-title">{song.title}</td>
                          <td className="song-duration">{song.duration}</td>
                    </tr>
                  )}
                </tbody>
            </table>
         </section>
      );
    }
 }


export default Album;

Answer 1

在对您的代码进行测试的过程中，我添加了 showPlayOnHover 属性以将其声明为false，以处理悬停时出现的按钮。

添加了呈现按钮的方法：

handlePlayOnHover = (song) => {
    this.setState({
        showPlayOnHover: !this.state.showPlayOnHover,
        isPlaying: !this.state.isPlaying
    })
    this.handleSongClick(song)
}

并且歌曲渲染结构已更新为：

<tr 
    className="song" key={index} 
    onClick={() => this.handleSongClick(song)}
    onMouseOver={() => this.handleOnHover(song)}
    onMouseOut={() => this.handleOnHover(song)}
>
      <td className="song-actions">
         <button>
            <span className="song-number">
                {!this.state.showPlayOnHover ? index+1 : <span className="ion-play"></span>}
            </span>
            <span className="ion-play"></span>
            <span className="ion-pause"></span>
        </button>
      </td>
      <td className="song-title">{song.title}</td>
      <td className="song-duration">{song.duration}</td>
</tr>

方法 handleOnHover 负责有条件地显示鼠标悬停时的播放按钮和歌曲悬停时的歌曲编号。

将onMouseEnter和onMouseLeave事件添加到音乐播放器

1 个答案: