files/zh-cn/web/api/datatransfer/items/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

---
title: DataTransfer.items
slug: Web/API/DataTransfer/items
translation_of: Web/API/DataTransfer/items
---
<div>{{APIRef("HTML Drag and Drop API")}}</div>

<p>{{domxref("DataTransfer")}}的<code>items</code> 属性只读，是拖动操作中 {{domxref("DataTransferItem","数据传输项")}}的{{domxref("DataTransferItemList","列表")}}。该列表包含了操作中每一项目的对应项，如果操作没有项目，则列表为空。</p>

<h2 id="语法">语法</h2>

<pre class="syntaxbox"><em>itemList</em> = <em>dataTransfer</em>.items;
</pre>

<h3 id="返回值">返回值</h3>

<p>一个{{domxref("DataTransferItemList")}} 对象，包含了表示拖动操作中被拖动项的{{domxref("DataTransferItem")}}对象，每一个拖动项对应一个列表项。如果拖动操作中没有数据，则列表为空。</p>

<h2 id="示例">示例</h2>

<p>这个例子演示了 <code>items</code> 和 {{domxref("DataTransfer.types","types")}} 属性的用法.</p>

<pre class="brush: js">&lt;!DOCTYPE html&gt;
&lt;html lang=en&gt;
&lt;title&gt;Examples of DataTransfer.{types,items} properties&lt;/title&gt;
&lt;meta content="width=device-width"&gt;
&lt;style&gt;
  div {
    margin: 0em;
    padding: 2em;
  }
  #target {
    border: 1px solid black;
  }
&lt;/style&gt;
&lt;script&gt;
function dragstart_handler(ev) {
 console.log("dragStart: target.id = " + ev.target.id);
 // Add this element's id to the drag payload so the drop handler will
 // know which element to add to its tree
 ev.dataTransfer.setData("text/plain", ev.target.id);
 ev.dataTransfer.effectAllowed = "move";
}

function drop_handler(ev) {
 console.log("drop: target.id = " + ev.target.id);
 ev.preventDefault();
 // Get the id of the target and add the moved element to the target's DOM
 var data = ev.dataTransfer.getData("text");
 ev.target.appendChild(document.getElementById(data));
 // Print each format type
 if (ev.dataTransfer.types != null) {
   for (var i=0; i &lt; ev.dataTransfer.types.length; i++) {
     console.log("... types[" + i + "] = " + ev.dataTransfer.types[i]);
   }
 }
 // Print each item's "kind" and "type"
 if (ev.dataTransfer.items != null) {
   for (var i=0; i &lt; ev.dataTransfer.items.length; i++) {
     console.log("... items[" + i + "].kind = " + ev.dataTransfer.items[i].kind + " ; type = " + ev.dataTransfer.items[i].type);
   }
 }
}

function dragover_handler(ev) {
 console.log("dragOver");
 ev.preventDefault();
 // Set the dropEffect to move
 ev.dataTransfer.dropEffect = "move"
}
&lt;/script&gt;
&lt;body&gt;
&lt;h1&gt;Examples of &lt;code&gt;DataTransfer&lt;/code&gt;.{&lt;code&gt;types&lt;/code&gt;, &lt;code&gt;items&lt;/code&gt;} properties&lt;/h1&gt;
 &lt;ul&gt;
   &lt;li id="i1" ondragstart="dragstart_handler(event);" draggable="true"&gt;Drag Item 1 to the Drop Zone&lt;/li&gt;
   &lt;li id="i2" ondragstart="dragstart_handler(event);" draggable="true"&gt;Drag Item 2 to the Drop Zone&lt;/li&gt;
 &lt;/ul&gt;
 &lt;div id="target" ondrop="drop_handler(event);" ondragover="dragover_handler(event);"&gt;Drop Zone&lt;/div&gt;
&lt;/body&gt;
&lt;/html&gt;
</pre>

<h2 id="规范">规范</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">规范</th>
   <th scope="col">状态</th>
   <th scope="col">备注</th>
  </tr>
  <tr>
   <td>{{SpecName("HTML WHATWG", "interaction.html#dom-datatransfer-items", "items")}}</td>
   <td>{{Spec2("HTML WHATWG")}}</td>
   <td></td>
  </tr>
  <tr>
   <td>{{SpecName("HTML5.1", "editing.html#dom-datatransfer-items", "items")}}</td>
   <td>{{Spec2("HTML5.1")}}</td>
   <td>Initial definition</td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器兼容性">浏览器兼容性</h2>


<p>{{Compat("api.DataTransfer.items")}}</p>

<h2 id="另见">另见</h2>

<p>{{page("/en-US/docs/Web/API/DataTransfer", "See also")}}</p>