Auto margins don't center image in page

问题

In this example the image is not centered. Why? My browser is Google Chrome v10 on windows 7, not IE.

<img src="/img/logo.png" style="margin:0px auto;"/>

回答1:

add display:block; and it'll work. Images are inline by default

To clarify, the default width for a block element is auto, which of course fills the entire available width of the containing element.

By setting the margin to auto, the browser assigns half the remaining space to margin-left and the other half to margin-right.

回答2:

Under some circumstances (such as earlier versions of IE, Gecko, Webkit) and inheritance, elements with position:relative; will prevent margin:0 auto; from working, even if top, right, bottom, and left aren't set.

Setting the element to position:static; (the default) may fix it under these circumstances. Generally, block level elements with a specified width will respect margin:0 auto; using either relative or static positioning.

回答3:

You can center auto width div using display:table;

div{
margin: 0px auto;
float: none;
display: table;
}

回答4:

In my case the problem was that I had set min and max width without width itself.

回答5:

Whenever we don't add width and add margin:auto, I guess it will not work. It's from my experience. Width gives the idea where exactly it needs to provide equal margins.

回答6:

there is a alternative to margin-left:auto; margin-right: auto; or margin:0 auto; for the ones that use position:absolute; this is how:
you set the left position of the element to 50% (left:50%;) but that will not center it correctly in order for the element to be centered correctly you need to give it a margin of minus half of it`s width, that will center your element perfectly

here is an example: http://jsfiddle.net/35ERq/3/