The color and black/white of each part of the photo are exchanged

<Br/> <style> ul {width: 300px; height: 300px; margin: 0px auto; padding: 0px; overflow: hidden; background: transparent url (/study/2006_12_25/2006122516414543849.jpg)} li {list-style-type: none; width: 100px; height: 100px; float: left} li a {display: block; width: 100px; height: 100px; text-decoration: none; background: transparent url (http://www.jb51.net/upload/20072795511179.jpg) no-repeat 500px 500px;} a # item1: hover {background-position: 0 0;} a # item2: hover {background-position:-100px 0;} a # item3: hover {background-position:-200px 0;} a # item4: hover {background-position: 0-100px;} a # item5: hover {background-position:-100px-100px;} a # item6: hover {background-position: -200px-100px;} a # item7: hover {background-position: 0-200px;} a # item8: hover {background-position:-100px-200px ;} a # item9: hover {background-position:-200px-200px ;} </style> <ul> <li> </ li> </ul> <p>
[Ctrl + A select all Note: If you need to introduce external Js, You need to refresh it to execute]

Let's first look at the code

<Style>
Ul {width: 300px; height: 300px; margin: 0px auto; padding: 0px; overflow: hidden; background: transparent url (/study/2006_12_25/2006122516414543849.jpg )}
Li {list-style-type: none; width: 100px; height: 100px; float: left}
Li a {display: block; width: 100px; height: 100px; text-decoration: none;
Background: transparent url (/study/2006_12_25/2006122516411012132.jpg) no-repeat 500px ;}
A # item1: hover {background-position: 0 0 ;}
A # item2: hover {background-position:-100px 0 ;}
A # item3: hover {background-position:-200px 0 ;}
A # item4: hover {background-position: 0-100px ;}
A # item5: hover {background-position:-100px-100px ;}
A # item6: hover {background-position:-200px-100px ;}
A # item7: hover {background-position: 0-200px ;}
A # item8: hover {background-position:-100px-200px ;}
A # item9: hover {background-position:-200px-200px ;}
</Style>

<Ul>
<Li> <a id = "item1" href = "#" title = "Item 1"> </a> </li>
<Li> <a id = "item2" href = "#" title = "Item 2"> </a> </li>
<Li> <a id = "item3" href = "#" title = "Item 3"> </a> </li>
<Li> <a id = "item4" href = "#" title = "Item 4"> </a> </li>
<Li> <a id = "item5" href = "#" title = "Item 5"> </a> </li>
<Li> <a id = "item6" href = "#" title = "Item 6"> </a> </li>
<Li> <a id = "item7" href = "#" title = "Item 7"> </a> </li>
<Li> <a id = "item8" href = "#" title = "Item 8"> </a> </li>
<Li> <a id = "item9" href = "#" title = "Item 9"> </a> </li>
</Ul>

Is it very simple, and the image we use is only the two below

Now let's analyze the usage of background-position: at the beginning of Element A, the background position is set to background-position: 500px 500px, and its size is only 100px * 100px, therefore, all backgrounds under tag A are beyond the visible range and cannot be displayed. The black and white pictures we saw at the beginning are UL's background images. Then, when you move the mouse over element A, you can set the background movement size for each element A based on the position of each element A. This forms the alternate effect of the above black and white images.