blob: 1e01cff97a8e3a4c923f2fae36c58b233e2c87b4 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
---
title: AudioContext.suspend()
slug: Web/API/AudioContext/suspend
translation_of: Web/API/AudioContext/suspend
---
<p>{{ APIRef("Web Audio API") }}</p>
<p>{{ domxref("AudioContext") }} 接口的<code>suspend()</code> 方法暂停音频上下文对象中的进度，并暂时剥离进程对音频设备硬件的访问权限, 减少CPU和电池的使用。 当程序在一段时间内不会使用音频上下文对象时，这个方法对减少硬件资源占用是非常有用的。</p>
<p>若对{{domxref("OfflineAudioContext")}} 调用此方法，将会抛出 <code>INVALID_STATE_ERR</code> 错误。</p>
<h2 id="Syntax">Syntax</h2>
<pre class="brush: js notranslate">var audioCtx = new AudioContext();
audioCtx.suspend().then(function() { ... });
</pre>
<h3 id="Returns">Returns</h3>
<p>A {{jsxref("Promise")}} that resolves with void. The promise is rejected if the context has already been closed.</p>
<h2 id="Example">Example</h2>
<p>The following snippet is taken from our <a href="https://github.com/mdn/audiocontext-states/settings">AudioContext states demo</a> (<a href="http://mdn.github.io/audiocontext-states/">see it running live</a>.) When the suspend/resume button is clicked, the {{domxref("AudioContext.state")}} is queried — if it is <code>running</code>, <code>suspend()</code> is called; if it is <code>suspended</code>, {{domxref("resume")}} is called. In each case, the text label of the button is updated as appropriate once the promise resolves.</p>
<pre class="brush: js notranslate">susresBtn.onclick = function() {
if(audioCtx.state === 'running') {
audioCtx.suspend().then(function() {
susresBtn.textContent = 'Resume context';
});
} else if(audioCtx.state === 'suspended') {
audioCtx.resume().then(function() {
susresBtn.textContent = 'Suspend context';
});
}
}
</pre>
<h2 id="Specifications">Specifications</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">Specification</th>
<th scope="col">Status</th>
<th scope="col">Comment</th>
</tr>
<tr>
<td>{{SpecName('Web Audio API', '#widl-AudioContext-suspend-Promise-void', 'close()')}}</td>
<td>{{Spec2('Web Audio API')}}</td>
<td></td>
</tr>
</tbody>
</table>
<h2 id="Browser_compatibility">Browser compatibility</h2>
<div>{{CompatibilityTable}}</div>
<div id="compat-desktop">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Chrome</th>
<th>Firefox (Gecko)</th>
<th>Internet Explorer</th>
<th>Opera</th>
<th>Safari (WebKit)</th>
</tr>
<tr>
<td>Basic support</td>
<td>{{CompatChrome(41.0)}}</td>
<td>{{CompatGeckoDesktop(40.0)}}</td>
<td>{{CompatNo}}</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatUnknown}}</td>
</tr>
</tbody>
</table>
</div>
<div id="compat-mobile">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Android</th>
<th>Firefox Mobile (Gecko)</th>
<th>Firefox OS</th>
<th>IE Mobile</th>
<th>Opera Mobile</th>
<th>Safari Mobile</th>
<th>Chrome for Android</th>
</tr>
<tr>
<td>Basic support</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatChrome(41.0)}}</td>
</tr>
</tbody>
</table>
</div>
<h2 id="See_also">See also</h2>
<ul>
<li><a href="/en-US/docs/Web_Audio_API/Using_Web_Audio_API">Using the Web Audio API</a></li>
<li><a href="/en-US/docs/Web/API/Web_Audio_API">Web Audio API</a></li>
</ul>
|
