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关于javascript：如何去掉这个循环来分别调用div元素？

codeneng 2023-03-28 原文

How to remove this loop to call div elements separately?

这是我用于音频播放器的代码：

https://codepen.io/katzkode/pen/ZbxYYG

它的作用：

使用循环为每首歌曲一次创建多个音频播放器(通过使用单个 div 元素)。

循环：

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/* createAudioElements
 * create audio elements for each file in files */
function createAudioElements() {
    for (f in files) {
        var audioString ="<source src="http://www.alexkatz.me/codepen/music/" + files[f] +""></audio>";
        $("#audio-players").append(audioString);
    }
}

/* createAudioPlayers
 * create audio players for each file in files */
function createAudioPlayers() {
    for (f in files) {
        var playerString ="<button id="playbutton-" + f +"" class="play playbutton"></button>";
        $("#audio-players").append(playerString);
    }
}

var 文件：

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var files = ["interlude.mp3", // 0
           "chooseyourweapon.mp3", // 1
           "interlude.mp3", // 2
           "scriptures.mp3" // 3
            ];

在我使用时在 HTML 中调用：

1
 

我要完成的工作：

删除循环，以便我可以单独插入任何播放器并单独调整它们但是我想要这样：https://puu.sh/ynD4q/6ab2ba7816.png

我想使用此代码来调用所需的音频播放器：

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    <source src="http://www.alexkatz.me/codepen/music/interlude.mp3">
</audio>

    <button id="playbutton-0" class="play playbutton"></button>

当我尝试使用它时，播放/停止/更改位置按钮停止工作。

这让我发疯了，我刚开始学习 jQuery。非常感谢！

将 files 数组更改为 settings 对象，并为具有 elementId 和 src 属性的每个文件添加对象：

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var settings = [
    {"elementId" :"audio-player-1","src" :"http://www.alexkatz.me/codepen/music/interlude.mp3"},
    {"elementId" :"audio-player-2","src" :"http://www.alexkatz.me/codepen/music/chooseyourweapon.mp3"},
    {"elementId" :"audio-player-3","src" :"http://www.alexkatz.me/codepen/music/scriptures.mp3"}
];

它非常有用，因为你可以添加任何你想要的属性。并且使用 src 属性，您可以从任何允许它的网站添加音频文件。

然后在 createAudioElements 中设置新的 src 属性为 settings[f].src.

之后在 createAudioElements 和 createAudioPlayers 函数中将选择器名称(循环中收集的行添加到该名称)更改为从相关 elementId 属性 $("#" + files[f].elementId) 动态生成的名称。

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// Event listener for DOM
document.addEventListener("DOMContentLoaded", theDOMHasLoaded, false);

// array of audio files (stored in a folder called music)
var settings = [{
   "elementId":"audio-player-1",
   "src":"http://www.alexkatz.me/codepen/music/interlude.mp3"
  },
  {
   "elementId":"audio-player-2",
   "src":"http://www.alexkatz.me/codepen/music/chooseyourweapon.mp3"
  },
  {
   "elementId":"audio-player-3",
   "src":"http://www.alexkatz.me/codepen/music/scriptures.mp3"
  }
];

///////////////////////////////////////////////
// Find and store audio info
///////////////////////////////////////////////

// array for AudioObjects
var audioList = [];
// components and the index for their AudioObject
var componentDict = {};
// store AudioObject that is currently playing
var playingAudio = null;
// store playhead id if one is being dragged
var onplayhead = null;

/* AudioObject Constructor */
function AudioObject(audio, duration) {
  this.audio = audio;
  this.id = audio.id;
  this.duration = duration;
}
/* bindAudioPlayer
 * Store audioplayer components in correct AudioObject
 * num identifes correct audioplayer
 */
AudioObject.prototype.bindAudioPlayer = function(num) {
  this.audioplayer = document.getElementById("audioplayer-" + num);
  this.playbutton = document.getElementById("playbutton-" + num);
  this.timeline = document.getElementById("timeline-" + num);
  this.playhead = document.getElementById("playhead-" + num);
  this.timelineWidth = this.timeline.offsetWidth - this.playhead.offsetWidth
}

/* addEventListeners() */
AudioObject.prototype.addEventListeners = function() {
  this.audio.addEventListener("timeupdate", AudioObject.prototype.timeUpdate, false);
  this.audio.addEventListener("durationchange", AudioObject.prototype.durationChange, false);
  this.timeline.addEventListener("click", AudioObject.prototype.timelineClick, false);
  this.playbutton.addEventListener("click", AudioObject.prototype.pressPlay, false);
  // Makes playhead draggable
  this.playhead.addEventListener('mousedown', AudioObject.prototype.mouseDown, false);
  window.addEventListener('mouseup', mouseUp, false);
}

/* populateAudioList */
function populateAudioList() {
  var audioElements = document.getElementsByClassName("audio");
  for (i = 0; i < audioElements.length; i++) {
    audioList.push(
      new AudioObject(audioElements[i], 0)
    );
    audioList[i].bindAudioPlayer(i);
    audioList[i].addEventListeners();
  }
}

/* populateComponentDictionary()
 * {key=element id : value=index of audioList} */
function populateComponentDictionary() {
  for (i = 0; i < audioList.length; i++) {
    componentDict[audioList[i].audio.id] = i;
    componentDict[audioList[i].playbutton.id] = i;
    componentDict[audioList[i].timeline.id] = i;
    componentDict[audioList[i].playhead.id] = i;
  }
}

///////////////////////////////////////////////
// Update Audio Player
///////////////////////////////////////////////

/* durationChange
 * set duration for AudioObject */
AudioObject.prototype.durationChange = function() {
  var ao = audioList[getAudioListIndex(this.id)];
  ao.duration = this.duration;
}

/* pressPlay()
 * call play() for correct AudioObject
 */
AudioObject.prototype.pressPlay = function() {
  var index = getAudioListIndex(this.id);
  audioList[index].play();
}

/* play()
 * play or pause selected audio, if there is a song playing pause it
 */
AudioObject.prototype.play = function() {
  if (this == playingAudio) {
    playingAudio = null;
    this.audio.pause();
    changeClass(this.playbutton,"playbutton play");
  }
  // else check if playing audio exists and pause it, then start this
  else {
    if (playingAudio != null) {
      playingAudio.audio.pause();
      changeClass(playingAudio.playbutton,"playbutton play");
    }
    this.audio.play();
    playingAudio = this;
    changeClass(this.playbutton,"playbutton pause");
  }
}

/* timelineClick()
 * get timeline's AudioObject
 */
AudioObject.prototype.timelineClick = function(event) {
  var ao = audioList[getAudioListIndex(this.id)];
  ao.audio.currentTime = ao.audio.duration * clickPercent(event, ao.timeline, ao.timelineWidth);
}

/* mouseDown */
AudioObject.prototype.mouseDown = function(event) {
  onplayhead = this.id;
  var ao = audioList[getAudioListIndex(this.id)];
  window.addEventListener('mousemove', AudioObject.prototype.moveplayhead, true);
  ao.audio.removeEventListener('timeupdate', AudioObject.prototype.timeUpdate, false);
}

/* mouseUp EventListener
 * getting input from all mouse clicks */
function mouseUp(e) {
  if (onplayhead != null) {
    var ao = audioList[getAudioListIndex(onplayhead)];
    window.removeEventListener('mousemove', AudioObject.prototype.moveplayhead, true);
    // change current time
    ao.audio.currentTime = ao.audio.duration * clickPercent(e, ao.timeline, ao.timelineWidth);
    ao.audio.addEventListener('timeupdate', AudioObject.prototype.timeUpdate, false);
  }
  onplayhead = null;
}

/* mousemove EventListener
 * Moves playhead as user drags */
AudioObject.prototype.moveplayhead = function(e) {
  var ao = audioList[getAudioListIndex(onplayhead)];
  var newMargLeft = e.clientX - getPosition(ao.timeline);

  if (newMargLeft >= 0 && newMargLeft <= ao.timelineWidth) {
    document.getElementById(onplayhead).style.marginLeft = newMargLeft +"px";
  }
  if (newMargLeft < 0) {
    playhead.style.marginLeft ="0px";
  }
  if (newMargLeft > ao.timelineWidth) {
    playhead.style.marginLeft = ao.timelineWidth +"px";
  }
}

/* timeUpdate
 * Synchronizes playhead position with current point in audio
 * this is the html audio element
 */
AudioObject.prototype.timeUpdate = function() {
  // audio element's AudioObject
  var ao = audioList[getAudioListIndex(this.id)];
  var playPercent = ao.timelineWidth * (ao.audio.currentTime / ao.duration);
  ao.playhead.style.marginLeft = playPercent +"px";
  // If song is over
  if (ao.audio.currentTime == ao.duration) {
    changeClass(ao.playbutton,"playbutton play");
    ao.audio.currentTime = 0;
    ao.audio.pause();
    playingAudio = null;
  }
}

///////////////////////////////////////////////
// Utility Methods
///////////////////////////////////////////////

/* changeClass
 * overwrites element's class names */
function changeClass(element, newClasses) {
  element.className = newClasses;
}

/* getAudioListIndex
 * Given an element's id, find the index in audioList for the correct AudioObject */
function getAudioListIndex(id) {
  return componentDict[id];
}

/* clickPercent()
 * returns click as decimal (.77) of the total timelineWidth */
function clickPercent(e, timeline, timelineWidth) {
  return (event.clientX - getPosition(timeline)) / timelineWidth;
}

// getPosition
// Returns elements left position relative to top-left of viewport
function getPosition(el) {
  return el.getBoundingClientRect().left;
}
///////////////////////////////////////////////
// GENERATE HTML FOR AUDIO ELEMENTS AND PLAYERS
///////////////////////////////////////////////

/* createAudioElements
 * create audio elements for each file in settings */
function createAudioElements() {
  for (f in settings) {
    var audioString ="<source src="" + settings[f].src +""></audio>";
    $("#" + settings[f].elementId).append(audioString);
  }
}

/* createAudioPlayers
 * create audio players for each file in settings */
function createAudioPlayers() {
  for (f in settings) {
    var playerString ="<button id="playbutton-" + f +"" class="play playbutton">" +
     "</button>";
    $("#" + settings[f].elementId).append(playerString);
  }
}

/* theDOMHasLoaded()
 * Execute when DOM is loaded */
function theDOMHasLoaded(e) {
  // Generate HTML for audio elements and audio players
  createAudioElements();
  createAudioPlayers();

  // Populate Audio List
  populateAudioList();
  populateComponentDictionary();
}
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.audioplayer {
  width: 480px;
  height: 60px;
  margin: 50px auto auto auto;
  border: solid;
}

.playbutton {
  height: 60px;
  width: 60px;
  border: none;
  float: left;
  outline: none;
}

.play {
  background: url('http://www.alexkatz.me/codepen/img/play.png');
}

.pause {
  background: url('http://www.alexkatz.me/codepen/img/pause.png');
}

.play,
.pause {
  background-size: 50% 50%;
  background-repeat: no-repeat;
  background-position: center;
}

.timeline {
  width: 400px;
  height: 20px;
  margin-top: 20px;
  float: left;
  border-radius: 15px;
  background: rgba(0, 0, 0, .3);
}

.playhead {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  margin-top: 1px;
  background: rgba(0, 0, 0, 1);
  cursor: pointer;
}
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<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js">
player 1

player 2

player 3

  • 你是我的救星，谢谢。最后！最后一个问题。如何将一些文件附加到 changeClass(this.playbutton,"playbutton play"); ？就像你对 function createAudioPlayers() { for (f in settings) { 所做的一样，非常感谢，你太棒了，谢谢。
  • 在 AudioObject.prototype.play 函数的第一行添加 var fileIndex = parseInt(this.audio.id.replace("audio-","")) 并在 changeClass 函数中使用此值。

您只需要更改新音频元素的 id，
查看工作演示

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// Event listener for DOM
document.addEventListener("DOMContentLoaded", theDOMHasLoaded, false);

// array of audio files (stored in a folder called music)
var files = ["interlude.mp3", // 0
 "chooseyourweapon.mp3", // 1
 "interlude.mp3", // 2
 "scriptures.mp3" // 3
];

///////////////////////////////////////////////
// Find and store audio info
///////////////////////////////////////////////

// array for AudioObjects
var audioList = [];
// components and the index for their AudioObject
var componentDict = {};
// store AudioObject that is currently playing
var playingAudio = null;
// store playhead id if one is being dragged
var onplayhead = null;

/* AudioObject Constructor */
function AudioObject(audio, duration) {
  this.audio = audio;
  this.id = audio.id;
  this.duration = duration;
}
/* bindAudioPlayer
 * Store audioplayer components in correct AudioObject
 * num identifes correct audioplayer
 */
AudioObject.prototype.bindAudioPlayer = function(num) {
  this.audioplayer = document.getElementById("audioplayer-" + num);
  this.playbutton = document.getElementById("playbutton-" + num);
  this.timeline = document.getElementById("timeline-" + num);
  this.playhead = document.getElementById("playhead-" + num);
  this.timelineWidth = this.timeline.offsetWidth - this.playhead.offsetWidth
}

/* addEventListeners() */
AudioObject.prototype.addEventListeners = function() {
  this.audio.addEventListener("timeupdate", AudioObject.prototype.timeUpdate, false);
  this.audio.addEventListener("durationchange", AudioObject.prototype.durationChange, false);
  this.timeline.addEventListener("click", AudioObject.prototype.timelineClick, false);
  this.playbutton.addEventListener("click", AudioObject.prototype.pressPlay, false);
  // Makes playhead draggable
  this.playhead.addEventListener('mousedown', AudioObject.prototype.mouseDown, false);
  window.addEventListener('mouseup', mouseUp, false);
}

/* populateAudioList */
function populateAudioList() {
  var audioElements = document.getElementsByClassName("audio");
  for (i = 0; i < audioElements.length; i++) {
    audioList.push(
      new AudioObject(audioElements[i], 0)
    );
    audioList[i].bindAudioPlayer(i);
    audioList[i].addEventListeners();
  }
}

/* populateComponentDictionary()
 * {key=element id : value=index of audioList} */
function populateComponentDictionary() {
  for (i = 0; i < audioList.length; i++) {
    componentDict[audioList[i].audio.id] = i;
    componentDict[audioList[i].playbutton.id] = i;
    componentDict[audioList[i].timeline.id] = i;
    componentDict[audioList[i].playhead.id] = i;
  }
}

///////////////////////////////////////////////
// Update Audio Player
///////////////////////////////////////////////

/* durationChange
 * set duration for AudioObject */
AudioObject.prototype.durationChange = function() {
  var ao = audioList[getAudioListIndex(this.id)];
  ao.duration = this.duration;
}

/* pressPlay()
 * call play() for correct AudioObject
 */
AudioObject.prototype.pressPlay = function() {
  var index = getAudioListIndex(this.id);
  audioList[index].play();
}

/* play()
 * play or pause selected audio, if there is a song playing pause it
 */
AudioObject.prototype.play = function() {
  if (this == playingAudio) {
    playingAudio = null;
    this.audio.pause();
    changeClass(this.playbutton,"playbutton play");
  }
  // else check if playing audio exists and pause it, then start this
  else {
    if (playingAudio != null) {
      playingAudio.audio.pause();
      changeClass(playingAudio.playbutton,"playbutton play");
    }
    this.audio.play();
    playingAudio = this;
    changeClass(this.playbutton,"playbutton pause");
  }
}

/* timelineClick()
 * get timeline's AudioObject
 */
AudioObject.prototype.timelineClick = function(event) {
  var ao = audioList[getAudioListIndex(this.id)];
  ao.audio.currentTime = ao.audio.duration * clickPercent(event, ao.timeline, ao.timelineWidth);
}

/* mouseDown */
AudioObject.prototype.mouseDown = function(event) {
  onplayhead = this.id;
  var ao = audioList[getAudioListIndex(this.id)];
  window.addEventListener('mousemove', AudioObject.prototype.moveplayhead, true);
  ao.audio.removeEventListener('timeupdate', AudioObject.prototype.timeUpdate, false);
}

/* mouseUp EventListener
 * getting input from all mouse clicks */
function mouseUp(e) {
  if (onplayhead != null) {
    var ao = audioList[getAudioListIndex(onplayhead)];
    window.removeEventListener('mousemove', AudioObject.prototype.moveplayhead, true);
    // change current time
    ao.audio.currentTime = ao.audio.duration * clickPercent(e, ao.timeline, ao.timelineWidth);
    ao.audio.addEventListener('timeupdate', AudioObject.prototype.timeUpdate, false);
  }
  onplayhead = null;
}

/* mousemove EventListener
 * Moves playhead as user drags */
AudioObject.prototype.moveplayhead = function(e) {
  var ao = audioList[getAudioListIndex(onplayhead)];
  var newMargLeft = e.clientX - getPosition(ao.timeline);

  if (newMargLeft >= 0 && newMargLeft <= ao.timelineWidth) {
    document.getElementById(onplayhead).style.marginLeft = newMargLeft +"px";
  }
  if (newMargLeft < 0) {
    playhead.style.marginLeft ="0px";
  }
  if (newMargLeft > ao.timelineWidth) {
    playhead.style.marginLeft = ao.timelineWidth +"px";
  }
}

/* timeUpdate
 * Synchronizes playhead position with current point in audio
 * this is the html audio element
 */
AudioObject.prototype.timeUpdate = function() {
  // audio element's AudioObject
  var ao = audioList[getAudioListIndex(this.id)];
  var playPercent = ao.timelineWidth * (ao.audio.currentTime / ao.duration);
  ao.playhead.style.marginLeft = playPercent +"px";
  // If song is over
  if (ao.audio.currentTime == ao.duration) {
    changeClass(ao.playbutton,"playbutton play");
    ao.audio.currentTime = 0;
    ao.audio.pause();
    playingAudio = null;
  }
}

///////////////////////////////////////////////
// Utility Methods
///////////////////////////////////////////////

/* changeClass
 * overwrites element's class names */
function changeClass(element, newClasses) {
  element.className = newClasses;
}

/* getAudioListIndex
 * Given an element's id, find the index in audioList for the correct AudioObject */
function getAudioListIndex(id) {
  return componentDict[id];
}

/* clickPercent()
 * returns click as decimal (.77) of the total timelineWidth */
function clickPercent(e, timeline, timelineWidth) {
  return (event.clientX - getPosition(timeline)) / timelineWidth;
}

// getPosition
// Returns elements left position relative to top-left of viewport
function getPosition(el) {
  return el.getBoundingClientRect().left;
}
///////////////////////////////////////////////
// GENERATE HTML FOR AUDIO ELEMENTS AND PLAYERS
///////////////////////////////////////////////

/* createAudioElements
 * create audio elements for each file in files */
function createAudioElements() {
  for (f in files) {
    var audioString ="<source src="http://www.alexkatz.me/codepen/music/" + files[f] +""></audio>";
    $("#audio-players").append(audioString);
  }
}

/* createAudioPlayers
 * create audio players for each file in files */
function createAudioPlayers() {
  for (f in files) {
    var playerString ="<button id="playbutton-" + f +"" class="play playbutton"></button>";
    $("#audio-players").append(playerString);
  }
}

/* theDOMHasLoaded()
 * Execute when DOM is loaded */
function theDOMHasLoaded(e) {
  // Generate HTML for audio elements and audio players
  createAudioElements();
  createAudioPlayers();

  // Populate Audio List
  populateAudioList();
  populateComponentDictionary();
}
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.audioplayer {
  width: 480px;
  height: 60px;
  margin: 50px auto auto auto;
  border: solid;
}

.playbutton {
  height: 60px;
  width: 60px;
  border: none;
  float: left;
  outline: none;
}

.play {
  background: url('http://www.alexkatz.me/codepen/img/play.png');
}

.pause {
  background: url('http://www.alexkatz.me/codepen/img/pause.png');
}

.play,
.pause {
  background-size: 50% 50%;
  background-repeat: no-repeat;
  background-position: center;
}

.timeline {
  width: 400px;
  height: 20px;
  margin-top: 20px;
  float: left;
  border-radius: 15px;
  background: rgba(0, 0, 0, .3);
}

.playhead {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  margin-top: 1px;
  background: rgba(0, 0, 0, 1);
  cursor: pointer;
}
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<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js">


    <source src="http://www.alexkatz.me/codepen/music/interlude.mp3">
</audio>

  <button id="playbutton-4" class="play playbutton"></button>

  • 感谢您的出色工作，但我想删除并使用完整的 "> 元素在任何我想要的地方插入我选择的单个播放器。

javascriptdivspanclassbrfor-loophtmljquery

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