属性：contenteditable

作用：将普通元素变为编辑框

范例：<div class="chatinput" contenteditable ></div>

属性值：

值	描述
true	规定可以编辑元素内容。
false	规定无法编辑元素内容。
classname	继承父元素的 contenteditable 属性。

浏览器支持性：

	IE	Firefox	Chrome	Safari	Opera	iOS Safari	Opera Mini	Opera Mobile	Android Browser
14 versions back			4.0: Supported
13 versions back			5.0: Supported
12 versions back		2.0: Not supported	6.0: Supported
11 versions back		3.0: Partial support	7.0: Supported
10 versions back		3.5: Supported	8.0: Supported
9 versions back		3.6: Supported	9.0: Supported
8 versions back		4.0: Supported	10.0: Supported		9.0: Supported
7 versions back		5.0: Supported	11.0: Supported		9.5-9.6: Supported
6 versions back		6.0: Supported	12.0: Supported		10.0-10.1: Supported
5 versions back		7.0: Supported	13.0: Supported		10.5: Supported
4 versions back	5.5: Supported	8.0: Supported	14.0: Supported	3.1: Supported	10.6: Supported			10.0: Not supported
3 versions back	6.0: Supported	9.0: Supported	15.0: Supported	3.2: Supported	11.0: Supported	3.2: Not supported		11.0: Not supported	2.1: Not supported
2 versions back	7.0: Supported	10.0: Supported	16.0: Supported	4.0: Supported	11.1: Supported	4.0-4.1: Not supported		11.1: Not supported	2.2: Not supported
Previous version	8.0: Supported	11.0: Supported	17.0: Supported	5.0: Supported	11.5: Supported	4.2-4.3: Not supported		11.5: Not supported	2.3: Not supported	3.0: Supported
Current	9.0: Supported	12.0: Supported	18.0: Supported	5.1: Supported	11.6: Supported	5.0: Supported	5.0-6.0: Not supported	12.0: Not supported	4.0: Supported
Near future	10.0: Supported	13.0: Supported	19.0: Supported	5.2: Supported	12.0: Supported
Farther future		14.0: Supported	20.0: Supported

 

如何使contenteditable元素 支持placeholder,使用css

 [contenteditable=true]:empty:before{
        content: attr(placeholder);
        display: block; /* For Firefox */
      }