CSS 位置：相对出现在位置：绝对
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position: relative appearing over position:absolute
提问by Louis W
Having a strange issue in IE7. In a number of spots, I have a DIV which has position: absolute on it (faux dropdown) whenever there is something behind it which has position: relative the relative positioned item will show through the other div.
在 IE7 中有一个奇怪的问题。在许多地方，我有一个 DIV，它有 position: absolute （假下拉），只要它后面有东西有 position:relative 相对定位的项目将通过另一个 div 显示。
Relativly positioned item does not have any z-index set, while the absolutely positioned item (the one I want on top) has a z-index of 1000.
相对定位的项目没有任何 z-index 集，而绝对定位的项目（我想要在顶部的项目）的 z-index 为 1000。
回答by Pat
I suspect you've already tried it, but set a z-indexon your relatively positioned element that's lower than your absolutely positioned element's z-indexas the first test.
我怀疑你已经尝试过了，但是z-index在你的相对定位元素上设置一个低于绝对定位元素的 az-index作为第一个测试。
If that doesn't work, you need to make sure both elements are in the same stacking context. In IE, whenever you apply the positionCSS rule to an element, it generates a new stacking context within that element. That means that z-index will only be properly respected within that element's children and children in other stacking contexts withlower z-indexes may still stack above.
如果这不起作用，您需要确保两个元素都在同一个堆叠上下文中。在 IE 中，每当您将positionCSS 规则应用于元素时，它都会在该元素内生成一个新的堆叠上下文。这意味着 z-index 只会在该元素的子元素中得到适当的尊重，而具有较低 z-index 的其他堆叠上下文中的子元素可能仍会堆叠在上面。
In your case, you either need to put the dropdown and button in the same stacking context orapply z-index to the 2 elements that are generating their separate stacking contexts.
在您的情况下，您要么需要将下拉菜单和按钮放在相同的堆叠上下文中，要么将 z-index 应用于生成其单独堆叠上下文的 2 个元素。
