files/zh-cn/web/events/readystatechange事件/index.html


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
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149

---
title: 'Document: readystatechange 事件'
slug: Web/Events/readystatechange事件
tags:
  - Reference
  - XMLHttpRequest
  - interactive
  - 事件
translation_of: Web/API/Document/readystatechange_event
---
<div>{{APIRef}}</div>

<p>当文档的 {{domxref("Document.readyState", "readyState")}} 属性发生改变时，会触发 <code>readystatechange</code> 事件。</p>

<table class="properties">
 <tbody>
  <tr>
   <th scope="row">是否冒泡</th>
   <td>否</td>
  </tr>
  <tr>
   <th scope="row">是否可取消</th>
   <td>否</td>
  </tr>
  <tr>
   <th scope="row">接口</th>
   <td>{{domxref("Event")}}</td>
  </tr>
  <tr>
   <th scope="row">Event handler 属性</th>
   <td><code>onreadystatechange</code></td>
  </tr>
 </tbody>
</table>

<h2 id="示例">示例</h2>

<h3 id="实时演示">实时演示</h3>

<h4 id="HTML">HTML</h4>

<pre class="brush: html">&lt;div class="controls"&gt;
  &lt;button id="reload" type="button"&gt;Reload&lt;/button&gt;
&lt;/div&gt;

&lt;div class="event-log"&gt;
  &lt;label&gt;Event log:&lt;/label&gt;
  &lt;textarea readonly class="event-log-contents" rows="8" cols="30"&gt;&lt;/textarea&gt;
&lt;/div&gt;</pre>

<div class="hidden">
<h4 id="CSS">CSS</h4>

<pre class="brush: css">body {
  display: grid;
  grid-template-areas: "control  log";
}

.controls {
  grid-area: control;
  display: flex;
  align-items: center;
  justify-content: center;
}

.event-log {
  grid-area: log;
}

.event-log-contents {
  resize: none;
}

label, button {
  display: block;
}

#reload {
  height: 2rem;
}

</pre>
</div>

<h4 id="JS">JS</h4>

<pre class="brush: js">const log = document.querySelector('.event-log-contents');
const reload = document.querySelector('#reload');

reload.addEventListener('click', () =&gt; {
  log.textContent ='';
  window.setTimeout(() =&gt; {
      window.location.reload(true);
  }, 200);
});

window.addEventListener('load', (event) =&gt; {
    log.textContent = log.textContent + 'load\n';
});

document.addEventListener('readystatechange', (event) =&gt; {
    log.textContent = log.textContent + `readystate: ${document.readyState}\n`;
});

document.addEventListener('DOMContentLoaded', (event) =&gt; {
    log.textContent = log.textContent + `DOMContentLoaded\n`;
});

</pre>

<h4 id="结果">结果</h4>

<p><iframe class="live-sample-frame sample-code-frame" frameborder="0" height="160px" id="frame_Live_example" src="https://mdn.mozillademos.org/en-US/docs/Web/API/Document/readystatechange_event$samples/Live_example?revision=1607037" width="100%"></iframe></p>

<h2 id="规范">规范</h2>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">规范</th>
   <th scope="col">状态</th>
   <th scope="col">备注</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td>{{SpecName("HTML WHATWG", "indices.html#event-readystatechange", "readystatechange")}}</td>
   <td>{{Spec2("HTML WHATWG")}}</td>
   <td></td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器兼容性">浏览器兼容性</h2>


<p>{{Compat("api.Document.readystatechange_event")}}</p>

<p>IE 浏览器是一直支持 <code>readystatechange</code> 事件的，可作为 <a href="/zh-CN/docs/Mozilla_event_reference/DOMContentLoaded_(event)">DOMContentLoaded </a>事件的替代方法（参见<a href="https://developer.mozilla.org/en-US/docs/Mozilla_event_reference/DOMContentLoaded_%28event%29#Browser_compatibility">Browser compatibility</a>的注释 [2]）。</p>

<h2 id="参见">参见</h2>

<ul>
 <li>{{event("DOMContentLoaded")}}</li>
 <li>{{event("load")}}</li>
 <li>{{event("beforeunload")}}</li>
 <li>{{event("unload")}}</li>
</ul>