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

display: none; 

它将不会出现在页面上,也不会占用任何空间。

visibility: hidden; 

它隐藏了一个元素,但它仍然会占用与之前相同的空间。元素将被隐藏,但仍然会影响布局。

可见性:隐藏保留空间,而显示:无不保留空间。

无示例:https://www.w3schools.com/css/tryit.asp?filename=trycss_display_none

示例:https://www.w3schools.com/cssref/tryit.asp?filename=trycss_visibility

其他回答

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。

有一件事值得补充,尽管它没有被问到,是有第三个选项,使对象完全透明。考虑:

1 <a href="http://example.com" style="display: none;"> < / >链接。< br / > <a href="http://example.com" style="可见性:隐藏;"> < / >链接。< br / > <a href="http://example.com" style="不透明度:0;"> < / >链接。

(请务必点击上面的“运行代码片段”按钮查看结果。)

1和2之间的区别已经指出了(即2仍然占据空间)。但是,2和3之间有区别:在情况3中,鼠标停留在链接上时仍然会切换到手,用户仍然可以单击链接,Javascript事件仍然会在链接上触发。这通常不是你想要的行为(但有时可能是?)

另一个区别是,如果你选择文本,然后复制/粘贴为纯文本,你会得到以下结果:

1st link.
2nd  link.
3rd unseen link.

在情况3中,文本被复制了。也许这对于某种类型的水印是有用的,或者如果你想隐藏一个版权声明,如果一个粗心的用户复制/粘贴你的内容会显示出来?

这种差异不仅体现在样式上,还体现在使用JavaScript操作元素时的行为上。

显示效果及副作用:无:

目标元素从文档流中取出(不影响其他元素的布局); 所有的后代都会受到影响(也不会显示出来,并且不能“跳出”这个继承); 测量不能用于目标元素,也不能用于它的后代元素——它们根本不被渲染,因此它们的clientWidth, clienttheight, offsetWidth, offsetHeight, scrollWidth, scrollHeight, getBoundingClientRect(), getComputedStyle(),都返回0。

可见性的影响和副作用:隐藏:

目标元素从视图中隐藏,但没有从流中取出并影响布局,占用其正常空间; 目标元素及其后代的innerText(但不是innerHTML)返回空字符串。

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)

可见性:隐藏保留空间;显示:没有没有。