[英]Why event is triggered more than once?
我正在嘗試使用SoundManager2為音頻Javascript插件添加事件處理程序。 這是播放歌曲並等待歌曲結束以再次執行該功能的函數:
function songPlay (newSrc) {
htmlSound.src = newSrc;
htmlSound.load();
thisPlayer.find( ".total-position-scrubber" ).bind( "slide", function(event, ui) {
htmlSound.currentTime = ui.value;
});
var currentArtist = currentRow.find(".total-artist").text();
var currentTitle = currentRow.find(".total-title").text();
thisPlayer.find(".total-playing-artist").html(currentArtist);
thisPlayer.find(".total-playing-title").html(currentTitle);
htmlSound.addEventListener("timeupdate", function() {
var newVolume = thisPlayer.find( ".total-volume-slider" ).slider("option", "value");
htmlSound.volume = newVolume;
var duration = htmlSound.duration * 1000;
var durationTime = convertMilliseconds(duration, "mm:ss");
thisPlayer.find(".total-song-duration").html(durationTime.clock );
var position = htmlSound.currentTime * 1000;
var positionTime = convertMilliseconds(position, "mm:ss");
thisPlayer.find(".total-song-position").html(positionTime.clock );
thisPlayer.find( ".total-position-scrubber" ).slider("option", "max", duration/1000);
thisPlayer.find( ".total-position-scrubber" ).slider("option", "value", position/1000);
});
htmlSound.addEventListener("ended", function() {
// Find next checked song
currentRow = currentRow.nextAll(".can-play:first");
// If checked song exists after current song, load it
if(currentRow.length > 0)
{
var newSrc = currentRow.find("[src]").attr("src");
songPlay(newSrc);
}
else
{
// If no checked song exists after current song, load the first checked song in playlist
if(thisPlayer.find(".can-play").length > 0)
{
currentRow = thisPlayer.find(".can-play:first");
var newSrc = currentRow.find("[src]").attr("src");
songPlay(newSrc);
}
// Change pause button to play button
else
{
thisPlayer.find(".total-play").removeClass("total-pause");
}
}
// If song is playing while next button is clicked play next song
if(thisPlayer.find(".total-pause").length > 0)
{
htmlSound.play();
}
});
thisPlayer.find(".total-row .total-not-playing").removeClass("total-playing");
currentRow.find(".total-not-playing").addClass("total-playing");
}
唯一的問題是,每首歌曲結束時,都會多次觸發“結束”事件。 在“結束”事件之后,將執行該函數,然后再次執行songPlay()
函數(這是預期的行為),但是隨后,在歌曲完成之前,將再次觸發“結束”事件,同時應該等待歌曲的結尾。 知道造成這種行為的原因嗎?
newSrc
變量始終具有正確的值。
這是SoundManager2中的“結束”事件定義:
_html5_events = {
// HTML5 event-name-to-handler map
...
ended: _html5_event(function() {
var t = this._t;
_s._wD(_h5+'ended: '+t.sID);
t._onfinish();
}),
...
}
編輯:
出乎意料的是,它僅用以下聲明的函數替換匿名函數即可:
function eventListenerFunction() {
// Find next checked song
currentRow = currentRow.nextAll(".can-play:first");
// If checked song exists after current song, load it
if(currentRow.length > 0)
{
var newSrc = currentRow.find("[src]").attr("src");
songPlay(newSrc);
}
else
{
// If no checked song exists after current song, load the first checked song in playlist
if(thisPlayer.find(".can-play").length > 0)
{
currentRow = thisPlayer.find(".can-play:first");
var newSrc = currentRow.find("[src]").attr("src");
songPlay(newSrc);
}
// Change pause button to play button
else
{
thisPlayer.find(".total-play").removeClass("total-pause");
}
}
// If song is playing while next button is clicked play next song
if(thisPlayer.find(".total-pause").length > 0)
{
htmlSound.play();
}
});
function songPlay (newSrc) {
htmlSound.src = newSrc;
htmlSound.load();
thisPlayer.find( ".total-position-scrubber" ).bind( "slide", function(event, ui) {
htmlSound.currentTime = ui.value;
});
var currentArtist = currentRow.find(".total-artist").text();
var currentTitle = currentRow.find(".total-title").text();
thisPlayer.find(".total-playing-artist").html(currentArtist);
thisPlayer.find(".total-playing-title").html(currentTitle);
htmlSound.addEventListener("timeupdate", function() {
var newVolume = thisPlayer.find( ".total-volume-slider" ).slider("option", "value");
htmlSound.volume = newVolume;
var duration = htmlSound.duration * 1000;
var durationTime = convertMilliseconds(duration, "mm:ss");
thisPlayer.find(".total-song-duration").html(durationTime.clock );
var position = htmlSound.currentTime * 1000;
var positionTime = convertMilliseconds(position, "mm:ss");
thisPlayer.find(".total-song-position").html(positionTime.clock );
thisPlayer.find( ".total-position-scrubber" ).slider("option", "max", duration/1000);
thisPlayer.find( ".total-position-scrubber" ).slider("option", "value", position/1000);
});
htmlSound.addEventListener("ended", eventListenerFunction)
thisPlayer.find(".total-row .total-not-playing").removeClass("total-playing");
currentRow.find(".total-not-playing").addClass("total-playing");
}
但是,我想我應該在觸發函數之后使用$('body').off("ended")
來刪除事件偵聽器,如@Fallenreaper建議的那樣。
您在聽眾內部調用歌曲播放,這將在另一時間....另一時間和另一時間應用它。
遞歸。
>_>
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