CSS规则visibility:hidden和display:none都会导致元素不可见。这些是同义词吗?
当前回答
当涉及到子节点时，有很大的不同。例如:如果你有一个父div和一个嵌套的子div。所以如果你这样写:
<div id="parent" style="display:none;">
<div id="child" style="display:block;"></div>
</div>
在这种情况下，没有divs是可见的。但如果你这样写:
<div id="parent" style="visibility:hidden;">
<div id="child" style="visibility:visible;"></div>
</div>
然后子div将可见，而父div将不显示。
其他回答
可见性:隐藏将元素保留在页面中，并占用该空间，但不显示给用户。
显示:无将在页面中不可用，不占用任何空间。
可见性:隐藏对象仍然占据垂直高度的页面。与显示:无它是完全删除。如果你在图片下面有文字，并且你设置了display:none，那么文字会向上移动以填充图片所在的位置。如果你做可见性:隐藏文本将保持在相同的位置。
它们不是同义词。
Display:none将元素从页面的正常流程中移除，允许其他元素填充。
可见性:隐藏将元素留在页面的正常流程中，这样仍然会占用空间。
想象一下，你正在游乐园排队，排队的人非常吵闹，保安把他们从队伍中拉了出来。然后排队的每个人都向前移动一个位置来填补现在的空缺。这就像display:none。
与此类似的情况相比，如果你前面有人穿上了隐形斗篷。在观看这条线时，它看起来像有一个空白的空间，但人们无法真正填补那个空白，因为有人仍然在那里。这就像可见性:隐藏。
总结所有其他答案:
| visibility | display |
|---|---|
| element with visibility: hidden, is hidden for all practical purposes (mouse pointers, keyboard focus, screenreaders), but still occupies space in the rendered markup | element with display:none, is hidden for all practical purposes (mouse pointers, keyboard focus, screenreaders), and DOES NOT occupy space in the rendered markup |
| css transitions can be applied for visibility changes | css transitions can not be applied on display changes |
| you can make a parent visibility:hidden but a child with visibility: visible would still be shown | when parent is display:none, children can't override and make themselves visible |
| part of the DOM tree (so you can still target it with DOM queries) | part of the DOM tree (so you can still target it with DOM queries) |
| part of the render tree | NOT part of the render tree |
| any reflow / layout in the parent element or child elements, would possibly trigger a reflow in these elements as well, as they are part of the render tree. | any reflow / layout in the parent element, would not impact these elements, as these are not part of the render tree |
| toggling between visibility: hidden and visible, would possibly not trigger a reflow / layout. (According to this comment it does: What is the difference between visibility:hidden and display:none? and possibly according to this as well https://developers.google.com/speed/docs/insights/browser-reflow) | toggling between display:none to display: (something else), would lead to a layout /reflow as this element would now become part of the render tree |
| you can measure the element through DOM methods | you can not measure the element or its descendants using DOM methods |
| If you have a huge number of elements using visibility: none on the page, the browser might hang while rendering, as all these elements require layout, even though they are not shown | If you have a huge number of elements using display:none, they wouldn't impact the rendering as they are not part of the render tree |
资源:
https://developers.google.com/speed/docs/insights/browser-reflow http://www.stubbornella.org/content/2009/03/27/reflows-repaints-css-performance-making-your-javascript-slow/ visibility:hidden和display:none
其他信息:
还有一些浏览器支持特性，但它们似乎适用于非常老的浏览器，在其他答案中也有，所以我在这里没有讨论它们。 还有其他一些隐藏元素的方法，比如不透明度，或者屏幕外的绝对定位。所有这些方法在一些或其他的回答中都有涉及，并且都有一些缺点。 根据这条评论(可见性:hidden和display:none之间的性能差异)，如果你有很多元素使用display:none并且你将其更改为display:(其他)，它将导致单个回流，而如果你有多个可见性:hidden元素并且你将它们变为可见，它将导致每个元素的回流。(我不太明白)
除了所有其他答案外，IE8还有一个重要的区别:如果你使用display:none并试图获取元素的宽度或高度，IE8将返回0(而其他浏览器将返回实际的大小)。IE8仅为可见性返回正确的宽度或高度:隐藏。
