例如这种,当然这只是一个例子,其他的也行,如果可以,请简要说明一下用到哪些技能点和原理。
回复内容:
几个下拉菜单display:none按钮 :hover 给下拉菜单display:block
也许可以 无脚本,纯HTML和 CSS 实现的多级下拉菜单,在非 IE 内核浏览器和 IE8+ 表现完美。

主体使用ul>li>ul>li>......嵌套定义多级。
<span class="cp"><!DOCTYPE HTML></span>
<span class="nt"><html></span>
<span class="nt"><head></span>
<span class="nt"><meta</span> <span class="na">http-equiv=</span><span class="s">"Content-Type"</span> <span class="na">content=</span><span class="s">"text/html; charset=utf-8"</span><span class="nt">></span>
<span class="nt"><title></span>纯 CSS 多级菜单<span class="nt"></title></span>
<span class="nt"><style></span>
<span class="nc">.menu</span><span class="p">{}</span>
<span class="nc">.menu</span> <span class="nt">ul</span><span class="o">,</span><span class="nc">.menu</span> <span class="nt">li</span><span class="p">{</span><span class="k">margin</span><span class="o">:</span><span class="m">0</span><span class="p">;</span> <span class="k">padding</span><span class="o">:</span><span class="m">0</span><span class="p">;</span><span class="k">list-style</span><span class="o">:</span><span class="k">none</span> <span class="k">outside</span><span class="p">;}</span>
<span class="nc">.menu</span><span class="o">></span><span class="nt">ul</span><span class="p">{</span><span class="k">overflow</span><span class="o">:</span><span class="k">auto</span><span class="p">;</span> <span class="k">display</span><span class="o">:</span><span class="k">inline</span><span class="o">-</span><span class="k">block</span><span class="p">;}</span>
<span class="nc">.menu</span> <span class="nt">a</span><span class="o">,</span><span class="nc">.menu</span> <span class="nt">span</span><span class="p">{</span> <span class="k">cursor</span><span class="o">:</span><span class="k">default</span><span class="p">;</span> <span class="k">height</span><span class="o">:</span><span class="m">30px</span><span class="p">;</span> <span class="k">line-height</span><span class="o">:</span><span class="m">30px</span><span class="p">;</span> <span class="k">padding</span><span class="o">:</span><span class="m">0</span> <span class="m">5px</span><span class="p">;</span> <span class="k">display</span><span class="o">:</span><span class="k">block</span><span class="p">;</span> <span class="k">text</span><span class="o">-</span><span class="k">overflow</span><span class="o">:</span><span class="n">ellipsis</span><span class="p">;</span> <span class="k">overflow</span><span class="o">:</span><span class="k">hidden</span><span class="p">;</span> <span class="k">text-decoration</span><span class="o">:</span><span class="k">none</span><span class="p">;</span> <span class="k">color</span><span class="o">:</span><span class="n">MenuText</span><span class="p">;}</span>
<span class="nc">.menu</span> <span class="nt">a</span><span class="nd">:hover</span><span class="o">,</span><span class="nc">.menu</span> <span class="nt">span</span><span class="nd">:hover</span><span class="o">,</span><span class="nc">.menu</span> <span class="nt">li</span><span class="nd">:hover</span><span class="o">></span><span class="nt">a</span><span class="o">,</span><span class="nc">.menu</span> <span class="nt">li</span><span class="nd">:hover</span><span class="o">></span><span class="nt">span</span><span class="p">{</span><span class="k">color</span><span class="o">:</span><span class="n">HighlightText</span><span class="p">;}</span>
<span class="nc">.menu</span> <span class="nt">li</span><span class="nd">:hover</span><span class="p">{</span><span class="k">background-color</span><span class="o">:</span><span class="n">Highlight</span><span class="p">;}</span>
<span class="nc">.menu</span> <span class="nt">li</span><span class="nd">:hover</span><span class="o">></span><span class="nt">ul</span><span class="p">{</span><span class="k">display</span><span class="o">:</span><span class="k">block</span><span class="p">;}</span>
<span class="nc">.menu</span><span class="o">></span><span class="nt">ul</span><span class="o">></span><span class="nt">li</span><span class="p">{</span><span class="k">float</span><span class="o">:</span><span class="k">left</span><span class="p">;}</span>
<span class="nc">.menu</span><span class="o">></span><span class="nt">ul</span><span class="o">></span><span class="nt">li</span> <span class="nt">ul</span><span class="p">{</span><span class="k">display</span><span class="o">:</span><span class="k">none</span><span class="p">;</span><span class="k">float</span><span class="o">:</span><span class="k">left</span><span class="p">;</span> <span class="k">background-color</span><span class="o">:</span><span class="m">#fff</span><span class="p">;</span> <span class="k">border</span><span class="o">:</span><span class="m">1px</span> <span class="k">solid</span> <span class="n">Highlight</span><span class="p">;</span> <span class="k">position</span><span class="o">:</span><span class="k">absolute</span><span class="p">;}</span>
<span class="nc">.menu</span><span class="o">></span><span class="nt">ul</span><span class="o">></span><span class="nt">li</span> <span class="nt">li</span><span class="p">{</span><span class="k">padding-left</span><span class="o">:</span><span class="m">25px</span><span class="p">;</span><span class="k">margin</span><span class="o">:</span><span class="m">2px</span><span class="p">;</span><span class="k">background</span><span class="o">:</span><span class="k">transparent</span> <span class="sx">url(data:image/gif;base64,R0lGODlhEAAQAIAAAJmZmf///yH5BAAAAAAALAAAAAAQABAAAAIjhI9pwe2+nmRRIQrmjBrmYB1Y93Ak+IXVd6LtiIZwa5JqWAAAOw==)</span> <span class="k">no-repeat</span> <span class="m">5px</span> <span class="k">center</span><span class="p">;</span> <span class="k">width</span><span class="o">:</span><span class="m">150px</span><span class="p">;}</span>
<span class="nc">.menu</span><span class="o">></span><span class="nt">ul</span><span class="o">></span><span class="nt">li</span><span class="o">></span><span class="nt">ul</span><span class="o">></span><span class="nt">li</span> <span class="nt">ul</span><span class="p">{</span><span class="k">margin-left</span><span class="o">:</span><span class="m">140px</span><span class="p">;</span> <span class="k">margin-top</span><span class="o">:-</span><span class="m">30px</span><span class="p">;}</span>
<span class="nc">.menu</span> <span class="nt">li</span><span class="nc">.expand</span><span class="o">></span><span class="nt">a</span><span class="o">,</span><span class="nc">.menu</span> <span class="nt">li</span><span class="nc">.expand</span><span class="o">></span><span class="nt">span</span><span class="p">{</span><span class="k">background</span><span class="o">:</span><span class="k">transparent</span> <span class="sx">url(data:image/png;base64,R0lGODlhAwAQAIABAAAAAP///yH5BAEAAAEALAAAAAADABAAAAIKjI8JBtv/wko0FQA7)</span> <span class="k">no-repeat</span> <span class="k">right</span> <span class="k">center</span><span class="p">;</span> <span class="k">padding-right</span><span class="o">:</span><span class="m">10px</span><span class="p">;</span> <span class="k">margin-right</span><span class="o">:</span><span class="m">5px</span><span class="p">;}</span>
<span class="nc">.menu</span><span class="o">></span><span class="nt">ul</span><span class="o">></span><span class="nt">li</span><span class="nc">.expand</span><span class="o">></span><span class="nt">a</span><span class="o">,</span><span class="nc">.menu</span><span class="o">></span><span class="nt">ul</span><span class="o">></span><span class="nt">li</span><span class="nc">.expand</span><span class="o">></span><span class="nt">span</span><span class="p">{</span> <span class="k">background-image</span><span class="o">:</span><span class="sx">url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAYAAAADCAYAAACwAX77AAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAaSURBVBhXY2BgYPiPAwOFMSXBgjAA0wnmAwASVQv19UVKmwAAAABJRU5ErkJggg==)</span><span class="p">;}</span>
<span class="nt"></style></span>
<span class="nt"></head></span>
<span class="nt"><body></span>
<span class="nt"><div</span> <span class="na">id=</span><span class="s">"mainnav"</span> <span class="na">class=</span><span class="s">"menu"</span><span class="nt">></span>
<span class="nt"><ul></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li</span> <span class="na">class=</span><span class="s">"expand"</span><span class="nt">><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></span>
<span class="nt"><ul></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li</span> <span class="na">class=</span><span class="s">"expand"</span><span class="nt">><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>很长很长很长很长很长很长很长很长很长很长<span class="nt"></a></span>
<span class="nt"><ul></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li</span> <span class="na">class=</span><span class="s">"expand"</span><span class="nt">><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>LinkLink<span class="nt"></a></span>
<span class="nt"><ul></span>
<span class="nt"><li</span> <span class="na">class=</span><span class="s">"expand"</span><span class="nt">><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></span>
<span class="nt"><ul></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"></ul></span>
<span class="nt"></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li</span> <span class="na">class=</span><span class="s">"expand"</span><span class="nt">><span></span>span 菜单项<span class="nt"></span></span>
<span class="nt"><ul></span>
<span class="nt"><li><span></span>span 菜单项<span class="nt"></span></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"></ul></span>
<span class="nt"></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"></ul></span>
<span class="nt"></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"></ul></span>
<span class="nt"></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"></ul></span>
<span class="nt"></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Link<span class="nt"></a></li></span>
<span class="nt"></ul></span>
<span class="nt"></div></span>
<span class="nt"></body></span>
<span class="nt"></html></span>
既然你这么问了,我就当你是新手了,还好,我也是新手。下面开说:
感觉用select标签效果好像不是很好,效果如下:

首先复习一下基本知识:
display:



代码如下:

希望大神们能批评指正
最后的效果如图:

<span class="cp"><!DOCTYPE html></span>
<span class="nt"><html</span> <span class="na">lang=</span><span class="s">"en"</span><span class="nt">></span>
<span class="nt"><head></span>
<span class="nt"><meta</span> <span class="na">charset=</span><span class="s">"UTF-8"</span><span class="nt">></span>
<span class="nt"><title></span>下拉菜单<span class="nt"></title></span>
<span class="nt"><style </span><span class="na">type=</span><span class="s">"text/css"</span><span class="nt">></span>
<span class="nc">.bt</span><span class="p">{</span>
<span class="k">width</span><span class="o">:</span> <span class="m">50px</span><span class="p">;</span><span class="k">height</span><span class="o">:</span> <span class="m">28px</span><span class="p">;</span>
<span class="k">border</span><span class="o">:</span> <span class="m">1px</span> <span class="k">solid</span> <span class="m">#ddd</span><span class="p">;</span>
<span class="k">background-color</span><span class="o">:</span> <span class="m">#eee</span><span class="p">;</span>
<span class="k">font</span><span class="o">:</span><span class="m">12px</span> <span class="s2">"宋体"</span><span class="p">;</span>
<span class="p">}</span>
<span class="nc">.ct</span><span class="p">{</span>
<span class="k">display</span><span class="o">:</span> <span class="k">none</span><span class="p">;}</span>
<span class="nc">.dt</span><span class="p">{</span>
<span class="k">height</span><span class="o">:</span> <span class="m">30px</span><span class="p">;</span>
<span class="k">margin-top</span><span class="o">:</span> <span class="m">0px</span><span class="p">;</span>
<span class="k">border</span><span class="o">:</span> <span class="m">1px</span> <span class="k">solid</span> <span class="m">#ddd</span><span class="p">;</span>
<span class="k">background-color</span><span class="o">:</span> <span class="nb">white</span><span class="p">;</span>
<span class="k">padding</span><span class="o">:</span><span class="k">auto</span> <span class="m">10px</span><span class="p">;</span>
<span class="p">}</span>
<span class="nc">.dt1</span><span class="p">{</span>
<span class="k">height</span><span class="o">:</span> <span class="m">30px</span><span class="p">;</span>
<span class="k">margin-top</span><span class="o">:</span> <span class="m">1px</span><span class="p">;</span>
<span class="k">border</span><span class="o">:</span> <span class="m">1px</span> <span class="k">solid</span> <span class="m">#ddd</span><span class="p">;</span>
<span class="k">background-color</span><span class="o">:</span> <span class="nb">white</span><span class="p">;</span>
<span class="k">padding</span><span class="o">:</span><span class="k">auto</span> <span class="m">10px</span><span class="p">;}</span>
<span class="nc">.dt</span><span class="nd">:hover</span><span class="o">,</span><span class="nc">.dt1</span><span class="nd">:hover</span><span class="p">{</span><span class="k">background-color</span><span class="o">:</span> <span class="m">#ddd</span><span class="p">;}</span>
<span class="nc">.bt</span><span class="nd">:hover</span><span class="p">{</span><span class="k">background-color</span><span class="o">:</span> <span class="nb">green</span><span class="p">;}</span>
<span class="nc">.at</span><span class="nd">:hover</span> <span class="nc">.ct</span><span class="p">{</span><span class="k">display</span><span class="o">:</span> <span class="k">inline</span><span class="o">-</span><span class="k">block</span><span class="p">;}</span>
<span class="nt"></style></span>
<span class="nt"></head></span>
<span class="nt"><body></span>
<span class="nt"><div</span> <span class="na">class=</span><span class="s">"at"</span><span class="nt">></span>
<span class="nt"><div></span>
<span class="nt"><button</span> <span class="na">class=</span><span class="s">"bt"</span> <span class="na">type=</span><span class="s">"button"</span> <span class="nt">></span>按钮<span class="nt"></button></span>
<span class="nt"></div></span>
<span class="nt"><div</span> <span class="na">class=</span><span class="s">"ct"</span> <span class="nt">></span>
<span class="nt"><div</span> <span class="na">class=</span><span class="s">"dt1"</span><span class="nt">></span>下拉菜单<span class="nt"></div></span>
<span class="nt"><div</span> <span class="na">class=</span><span class="s">"dt"</span><span class="nt">></span>下拉菜单<span class="nt"></div></span>
<span class="nt"><div</span> <span class="na">class=</span><span class="s">"dt"</span><span class="nt">></span>下拉菜单<span class="nt"></div></span>
<span class="nt"><div</span> <span class="na">class=</span><span class="s">"dt"</span><span class="nt">></span>下拉菜单<span class="nt"></div></span>
<span class="nt"></div></span>
<span class="nt"></div></span>
<span class="nt"></div></span>
<span class="nt"></body></span>
<span class="nt"></html></span>
要求不高的话用bootstrap 就好了。做这个功能不难,难的是如何封装和复用。
个人看好polymer这种解决方案。
<span class="cp"><!DOCTYPE html></span>
<span class="nt"><html></span>
<span class="nt"><head></span>
<span class="nt"><meta</span> <span class="na">charset=</span><span class="s">"utf-8"</span><span class="nt">></span>
<span class="nt"><title></span>css实现下拉菜单<span class="nt"></title></span>
<span class="nt"><style </span><span class="na">type=</span><span class="s">"text/css"</span><span class="nt">></span>
<span class="o">*</span><span class="p">{</span>
<span class="k">margin</span><span class="o">:</span> <span class="m">0</span><span class="p">;</span>
<span class="k">padding</span><span class="o">:</span> <span class="m">0</span><span class="p">;</span>
<span class="p">}</span>
<span class="nf">#nav</span><span class="p">{</span>
<span class="k">background-color</span><span class="o">:</span> <span class="m">#eee</span><span class="p">;</span>
<span class="k">width</span><span class="o">:</span> <span class="m">300px</span><span class="p">;</span>
<span class="k">height</span><span class="o">:</span> <span class="m">40px</span><span class="p">;</span>
<span class="k">margin</span><span class="o">:</span> <span class="m">0</span> <span class="k">auto</span><span class="p">;</span>
<span class="p">}</span>
<span class="nt">ul</span><span class="p">{</span>
<span class="k">list-style</span><span class="o">:</span> <span class="k">none</span><span class="p">;</span>
<span class="p">}</span>
<span class="nt">ul</span> <span class="nt">li</span> <span class="p">{</span>
<span class="k">float</span><span class="o">:</span> <span class="k">left</span><span class="p">;</span>
<span class="k">line-height</span><span class="o">:</span> <span class="m">40px</span><span class="p">;</span>
<span class="k">text-align</span><span class="o">:</span> <span class="k">center</span><span class="p">;</span>
<span class="p">}</span>
<span class="nt">a</span><span class="p">{</span>
<span class="k">text-decoration</span><span class="o">:</span> <span class="k">none</span><span class="p">;</span>
<span class="k">color</span><span class="o">:</span><span class="m">#000</span><span class="p">;</span>
<span class="k">padding</span><span class="o">:</span> <span class="m">0</span> <span class="m">10px</span><span class="p">;</span>
<span class="k">display</span><span class="o">:</span> <span class="k">block</span><span class="p">;</span>
<span class="p">}</span>
<span class="nt">a</span><span class="nd">:hover</span><span class="p">{</span>
<span class="k">color</span><span class="o">:</span> <span class="m">#fff</span><span class="p">;</span>
<span class="k">background-color</span><span class="o">:</span> <span class="m">#666</span><span class="p">;</span>
<span class="p">}</span>
<span class="nt">ul</span> <span class="nt">li</span> <span class="nt">ul</span> <span class="nt">li</span><span class="p">{</span>
<span class="k">float</span><span class="o">:</span> <span class="k">none</span><span class="p">;</span>
<span class="k">background-color</span><span class="o">:</span> <span class="m">#eee</span><span class="p">;</span>
<span class="k">margin-top</span><span class="o">:</span> <span class="m">2px</span><span class="p">;</span>
<span class="p">}</span>
<span class="nt">ul</span> <span class="nt">li</span> <span class="nt">ul</span> <span class="p">{</span>
<span class="k">position</span><span class="o">:</span> <span class="k">absolute</span><span class="p">;</span>
<span class="k">display</span><span class="o">:</span> <span class="k">none</span><span class="p">;</span>
<span class="p">}</span>
<span class="nt">ul</span> <span class="nt">li</span> <span class="nt">ul</span> <span class="nt">li</span> <span class="nt">a</span><span class="nd">:hover</span><span class="p">{</span>
<span class="k">background-color</span><span class="o">:</span> <span class="m">#06f</span><span class="p">;</span>
<span class="p">}</span>
<span class="nt">ul</span> <span class="nt">li</span><span class="nd">:hover</span> <span class="nt">ul</span><span class="p">{</span>
<span class="k">display</span><span class="o">:</span> <span class="k">block</span><span class="p">;</span>
<span class="p">}</span>
<span class="nt"></style></span>
<span class="nt"></head></span>
<span class="nt"><body></span>
<span class="nt"><div</span> <span class="na">id=</span><span class="s">"nav"</span><span class="nt">></span>
<span class="nt"><ul></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>按钮1<span class="nt"></a></li></span>
<span class="nt"><li></span>
<span class="nt"><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>按钮2<span class="nt"></a></span>
<span class="nt"><ul></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>下拉菜单项<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>下拉菜单项<span class="nt"></a></li></span>
<span class="nt"></ul></span>
<span class="nt"></li></span>
<span class="nt"><li></span>
<span class="nt"><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>按钮3<span class="nt"></a></span>
<span class="nt"><ul></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>下拉菜单项<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>下拉菜单项<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>下拉菜单项<span class="nt"></a></li></span>
<span class="nt"></ul></span>
<span class="nt"></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>按钮4<span class="nt"></a></li></span>
<span class="nt"><li><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>按钮5<span class="nt"></a></li></span>
<span class="nt"></ul></span>
<span class="nt"></div></span>
<span class="nt"></body></span>
<span class="nt"></html></span>
这个是网易云课堂前端微专业的页面布局的期末测试题。
我也试一下。这里大部分答案都是hover事件触发下拉菜单出现。其实我总觉得这样不太自然,所以我尽力去做成(伪)点击触发。
---------------------------------------------------------------------
# 具体想法:
菜单是, 下拉菜单的容器是
然后利用a:focus + .dropdown{ ... } 来实现。
---------------------------------------------------------------------
要点1:CSS如何实现影响其他元素?
看这里 > html - How to affect other elements when a div is hovered
要点2: 如何做出(伪)点击触发?
基本用 a:focus,个人感觉自然一点。当然如果失去焦点,下拉菜单容器也会相应地隐藏。
--------------------------------------------------------------------
# HTML BODY 部分代码:
<span class="nt"><body></span>
<span class="nt"><a</span> <span class="na">href=</span><span class="s">"#"</span><span class="nt">></span>Menu<span class="nt"></a></span>
<span class="nt"><div</span> <span class="na">class=</span><span class="s">"drop-down"</span> <span class="na">id=</span><span class="s">"drop-down"</span><span class="nt">></span>
<span class="nt"><ul></span>
<span class="nt"><li></span>Option 1<span class="nt"></li></span>
<span class="nt"><li></span>Option 2<span class="nt"></li></span>
<span class="nt"><li></span>Option 3<span class="nt"></li></span>
<span class="nt"><li></span>Option 4<span class="nt"></li></span>
<span class="nt"></ul></span>
<span class="nt"></div></span>
<span class="nt"></body></span>
更正一点小错误,只有一个单选按钮时,选中后就不能取消选中了。所以最好用复选按钮。原答案如下
===========================
楼上有同学写了css用伪类:hover实现的下拉菜单 这是一种 我再补充下
下拉菜单抛开样式的不同 交互上无非两种
鼠标移到button上出现菜单(如楼上)
以及点击后出现菜单(我要说的)
题主问的是html+css 而很多同学提到了用js添加click事件 这也是大多数下拉菜单的做法
不过为了不跑题 就只用html+css 不用js 那就考css基本功了
这里简单说下思路
html结构如下
<span class="nt"><button></span>点击我出现下拉菜单<span class="nt"></button></span>
<span class="nt"><input</span> <span class="na">type=</span><span class="s">"checkbok"</span><span class="nt">></span>
<span class="nt"><div></span>
<span class="nt"><ul></span>
<span class="nt"><li></span>XXX<span class="nt"></li></span>
<span class="nt"><li></span>XXX<span class="nt"></li></span>
<span class="nt"><li></span>XXX<span class="nt"></li></span>
<span class="nt"><li></span>XXX<span class="nt"></li></span>
<span class="nt"></ul></span>
<span class="nt"></div></span>
用列表,隐藏,然后hover.的时候block就可以了
http://pepsized.com/css-only-alternative-to-the-select-element/如果想用纯css实现click效果:
http://tympanus.net/codrops/2012/12/17/css-click-events/

H5 dan HTML5 adalah konsep yang berbeza: HTML5 adalah versi HTML, yang mengandungi unsur -unsur baru dan API; H5 adalah rangka kerja pembangunan aplikasi mudah alih berdasarkan HTML5. HTML5 Parses dan membuat kod melalui pelayar, manakala aplikasi H5 perlu menjalankan bekas dan berinteraksi dengan kod asli melalui JavaScript.

Unsur -unsur utama HTML5 termasuk ,,,,,, dan lain -lain, yang digunakan untuk membina laman web moden. 1. Tentukan kandungan kepala, 2.

Tidak ada perbezaan antara HTML5 dan H5, iaitu singkatan HTML5. 1.HTML5 adalah versi kelima HTML, yang meningkatkan fungsi multimedia dan interaktif laman web. 2.H5 sering digunakan untuk merujuk kepada laman web atau aplikasi mudah alih berasaskan HTML5, dan sesuai untuk pelbagai peranti mudah alih.

HTML5 adalah versi terkini bahasa markup hiperteks, yang diseragamkan oleh W3C. HTML5 memperkenalkan tag semantik baru, sokongan multimedia dan peningkatan bentuk, meningkatkan struktur web, pengalaman pengguna dan kesan SEO. HTML5 memperkenalkan tag semantik baru, seperti,, dan lain -lain, untuk menjadikan struktur laman web lebih jelas dan kesan SEO lebih baik. HTML5 menyokong elemen multimedia dan tiada pemalam pihak ketiga diperlukan, meningkatkan pengalaman pengguna dan kelajuan memuatkan. HTML5 meningkatkan fungsi bentuk dan memperkenalkan jenis input baru seperti, dan lain -lain, yang meningkatkan pengalaman pengguna dan membentuk kecekapan pengesahan.

Bagaimana cara menulis kod HTML5 yang bersih dan cekap? Jawapannya adalah untuk mengelakkan kesilapan biasa dengan tag semantik, kod berstruktur, pengoptimuman prestasi dan mengelakkan kesilapan biasa. 1. Gunakan tag semantik seperti, dan lain -lain untuk meningkatkan kebolehbacaan kod dan kesan SEO. 2. Pastikan kod berstruktur dan boleh dibaca, menggunakan lekukan dan komen yang sesuai. 3. Mengoptimumkan prestasi dengan mengurangkan tag yang tidak perlu, menggunakan CDN dan kod pemampatan. 4. Elakkan kesilapan biasa, seperti tag tidak ditutup, dan pastikan kesahihan kod.

H5 meningkatkan pengalaman pengguna web dengan sokongan multimedia, penyimpanan luar talian dan pengoptimuman prestasi. 1) Sokongan multimedia: H5 dan Elemen Memudahkan pembangunan dan meningkatkan pengalaman pengguna. 2) Penyimpanan Luar Talian: WebStorage dan IndexedDB membenarkan penggunaan luar talian untuk meningkatkan pengalaman. 3) Pengoptimuman Prestasi: Pekerja web dan elemen mengoptimumkan prestasi untuk mengurangkan penggunaan jalur lebar.

Kod HTML5 terdiri daripada tag, elemen dan atribut: 1. Tag mentakrifkan jenis kandungan dan dikelilingi oleh kurungan sudut, seperti. 2. Unsur terdiri daripada tag permulaan, kandungan dan tag akhir, seperti kandungan. 3. Atribut menentukan pasangan nilai utama dalam tag permulaan, meningkatkan fungsi, seperti. Ini adalah unit asas untuk membina struktur web.

HTML5 adalah teknologi utama untuk membina laman web moden, menyediakan banyak elemen dan ciri -ciri baru. 1. HTML5 memperkenalkan unsur -unsur semantik seperti, dan lain -lain, yang meningkatkan struktur laman web dan SEO. 2. Sokongan unsur multimedia dan menanamkan media tanpa pemalam. 3. Borang meningkatkan jenis input baru dan sifat pengesahan, memudahkan proses pengesahan. 4. Menawarkan fungsi storan luar talian dan tempatan untuk meningkatkan prestasi laman web dan pengalaman pengguna.


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