Knockout绑定audio的pause事件致使音频没法中止

...时间过得真快, 一晃4天已通过去了, 然而本身并无动笔写什么. 自省.

看了看今天的工做, 感受好像没什么可写的. 不由在想是否是一天一篇有点儿难. 再一想, 这分明就是在给本身找理由. 就是再短也应该把当天学到的任何东西整理一下, 怎么都是有的写的! 若是彻底没得写, 那我却是要反思下我今天是否是太虚度了.

废话很少说, 整理下这两天的收获. (最近一直写code可是不多记录, 提醒本身之后坚持记录!)

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我发现我用knockout给audio元素绑定了pause事件, 形如<audio data-bind="event: { pause: pauseHandler }"...可是用$('audio').trigger('pause')没法暂停audio播放. 很诡异.

因而我为audio的play和pause事件都绑上了console.log, 发现trigger('play')会输出两次play而trigger('pause')只会输出一个pause. 可是若是用.play()和.pause()就能够正常地播放和中止音频, 同时只会输出一个play和pause.

为何$('audio').trigger('play')会出发playHandler两次而$('audio')[0].play()只会触发一次?

搜索一阵无果就在stackoverflow上问了一下, 获得的解答是:

trigger('play') triggers your handler programmatically, which dispatches the play event on the audio element, once the clip starts playing, the play event is dispatched again, triggering your handler a second time, whereas $('audio')[0].play() won't trigger your handler initially, it'll trigger the dom element's native play event, which, when it starts playing will trigger your handler

可是至于可否用trigger('play')只触发一次playHandler, 并无获得答复.

为何用Knockout绑定pause事件后没法用trigger('pause')暂停音频?

本身摸索出来了答案, 只要给pauseHandler加上return true;便可. 可是不明白为何必需要这么加, 因而问了一记, 本身才发现spec上写得清清楚楚:

By default, Knockout will prevent the event from taking any default action....However, if you do want to let the default action proceed, just return true from your event handler function.