Xhtml下不常用却很有用的标签_HTML/Xhtml_网页制作

 Xhtml有很多不常用却很有用的标签。有的能事半功倍，有的能改进语义，有的则能提高易用性，我总结了一些，总结的原则是有用而且能用，就是大多数浏览器得支持，否则就不算“上上签”了。只能望“签”兴叹又有什么用呢？
标签
    作用： 标签为页面中所有链接指定默认链接地址或链接目标。有时候我们需要让首页的链接全部在新窗口中打开，我们一般会这样写链接，而使用这个标签就能一下搞定了！
    属性：
        Href:链接地址
        target:目标，他的值可以是_blank,_parent,_self,_top,可以在除Strict模式下使用，这个用法我最先是在163.com上发现的。
    用法：

<code class="html"><span class="tag"><span class="tag">></span>></span> <br><span class="tag"><base>
<span class="aname"> href</span>=<span class="avalue">"http://www.qq.com/"</span> <span class="tag">/></span> ></span> <br><span class="tag"><base>
<span class="aname"> target</span>=<span class="avalue">"_blank"</span> <span class="tag">/></span> ></span> <br><span class="tag"></span></code><p><br><font size="4"><strong><caption>标签</caption></strong></font><br>    <strong>作用：</strong>caption标签用来定义表格的标题，给表格定义一个标题，来说明这个表格是干什么的，岂不是很有“语义”，caption应该写在table之后，默认的样式是居中显示在表格的顶部。你可以通过css来改变它的样式。<br>    <strong>用法：</strong><br></p>

<code class="html"><span class="tag"><table>
<span class="aname"> width</span>=<span class="avalue">"200"</span><span class="aname"> border</span>=<span class="avalue">"1"</span> <span class="tag">></span> <br><span class="tag"><caption>
<span class="tag">></span> <span class="mlcom"><!--caption应该写在table之后--></span> <br>其实我是caption <br><span class="tag"></span>
</caption></span> <br><span class="tag"><tr>
<span class="tag">></span> <br><span class="tag"></span><td>
<span class="tag">></span><span class="entity"> </span><span class="tag"></span>
</td> <br><span class="tag"></span><td>
<span class="tag">></span><span class="entity"> </span><span class="tag"></span>
</td> <br><span class="tag"></span>
</tr></span> <br><span class="tag"><tr>
<span class="tag">></span> <br><span class="tag"></span><td>
<span class="tag">></span><span class="entity"> </span><span class="tag"></span>
</td> <br><span class="tag"></span><td>
<span class="tag">></span><span class="entity"> </span><span class="tag"></span>
</td> <br><span class="tag"></span>
</tr></span> <br><span class="tag"></span>
</table></span></code><p><br><font size="4"><strong><thead>标签、</thead>
<tbody>标签、</tbody>
<tfoot>标签<br>    作用：thead、tfoot 
以及 
tbody标签跟他们的名字那样，分别是表格的头部（很多人只是用th）、主题、和底部，他们能让表格更加语义化的同时，也能让我们更加方便的控制表格的表现。国外还有人用很变态地方法用这三个表其做出标题能跟随表格，或者tbody固定高度，多出的行数出现滚动条。有兴趣的可以搜素下或者是这做一下。<br>注意：<font color="#ff0000">如果您使用 thead、tfoot 以及 tbody 
元素，您就必须使用全部的元素。它们的出现次序是：thead、tfoot、tbody，这样浏览器就可以在收到所有数据前呈现页脚了。</font><br>    <strong>用法：</strong><br>
<pre mergenum="16"><code class="html"><span class="tag"><table>
<span class="aname"> border</span>=<span class="avalue">"1"</span><span class="tag">></span> <br><span class="tag"><thead>
<span class="tag">></span> <br><span class="tag"><tr>
<span class="tag">></span> <br><span class="tag"></span><th>
<span class="tag">></span>科目<span class="tag"></span>
</th> <br><span class="tag"></span><th>
<span class="tag">></span>分数<span class="tag"></span>
</th> <br><span class="tag"></span>
</tr></span> <br><span class="tag"></span>
</thead></span> <br><span class="tag"><tfoot>
<span class="tag">></span> <br><span class="tag"><tr>
<span class="tag">></span> <br><span class="tag"></span><td>
<span class="tag">></span>总分<span class="tag"></span>
</td> <br><span class="tag"></span><td>
<span class="tag">></span>159<span class="tag"></span>
</td> <br><span class="tag"></span>
</tr></span> <br><span class="tag"></span>
</tfoot></span> <br> <br><span class="tag"><tbody>
<span class="tag">></span> <br><span class="tag"><tr>
<span class="tag">></span> <br><span class="tag"></span><td>
<span class="tag">></span>语文<span class="tag"></span>
</td> <br><span class="tag"></span><td>
<span class="tag">></span>99<span class="tag"></span>
</td> <br><span class="tag"></span>
</tr></span> <br><span class="tag"><tr>
<span class="tag">></span> <br><span class="tag"></span><td>
<span class="tag">></span>数学<span class="tag"></span>
</td> <br><span class="tag"></span><td>
<span class="tag">></span>60<span class="tag"></span>
</td> <br><span class="tag"></span>
</tr></span> <br><span class="tag"></span>
</tbody></span> <br><span class="tag"></span>
</table></span></code><p><br><font size="4"><strong><fieldset>标签和<legend>标签</legend>
</fieldset></strong></font><br>    <strong>作用：</strong></p>

元素用来分类表单中的元素，而

则能给这个组定义一个标题。你一定见过类似下面domo的布局吧！他们也可以通过css定义样式。
    用法:

<code class="html"><span class="tag"><form>
<span class="tag">></span> <br><span class="tag"><fieldset>
<span class="tag">></span> <br><span class="tag"><legend>
<span class="tag">></span>基本信息<span class="tag"></span>
</legend></span> <br>姓名: <span class="tag"><input><span class="aname"> type</span>=<span class="avalue">"text"</span> <span class="tag">/></span> <br>性别: <span class="tag"><input><span class="aname"> type</span>=<span class="avalue">"text"</span> <span class="tag">/></span> <br><span class="tag"></span></span></span>
</fieldset></span> <br><span class="tag"></span>
</form></span></code><p><br><font size="4"><strong><sub> 标签和<sup> 标签</sup></sub></strong></font><br>    作用：<sub> 
标签和<sub> 
标签分别是上标和下标，虽然他们在各个浏览器的表现不一样，你<br>同样可以使用css定义他们的样式。<br>    <strong>用法：</strong><br></sub></sub></p>

<code class="html">2<span class="tag"><sup><span class="tag">></span>我是上标<span class="tag"></span></sup></span> <br>2<span class="tag"><sub><span class="tag">></span>我是下标<span class="tag"></span></sub></span></code><p><br><font size="4"><strong><label>标签</label></strong></font><br>    <strong>作用：</strong>label 
标签的使用可以扩大表单的点击区域来改进表单的易用性。看看下面的用法：点击文字的时候相当于点击了单选控件，这样用户体验是不是会更好一些？<br>    <strong>用法：</strong><br></p>

<code class="html"><span class="tag"><form>
<span class="tag">></span> <br><span class="tag"><label><span class="aname"> for</span>=<span class="avalue">"nan"</span><span class="tag">></span>先生<span class="tag"></span></label></span> <br><span class="tag"><input><span class="aname"> type</span>=<span class="avalue">"radio"</span><span class="aname"> name</span>=<span class="avalue">"sex"</span><span class="aname"> id</span>=<span class="avalue">"nan"</span> <span class="tag">/></span> <br><span class="tag"><br> <span class="tag">/></span> <br><span class="tag"><label><span class="aname"> for</span>=<span class="avalue">"nv"</span><span class="tag">></span>女士<span class="tag"></span></label></span> <br><span class="tag"><input><span class="aname"> type</span>=<span class="avalue">"radio"</span><span class="aname"> name</span>=<span class="avalue">"sex"</span><span class="aname"> id</span>=<span class="avalue">"nv"</span> <span class="tag">/></span> <br><span class="tag"></span></span></span></span>
</form></span></code><br><font size="4"><strong><optgroup> 标签</optgroup></strong></font><br>    <strong>作用：</strong><option></option> 
标签可以给select中的option进行分组，这在下拉项目很多的时候很有用，配合label标签给每组命名。你也可以像淘宝那样给每组用css定义不同的颜色。<br>    <strong>用法：</strong><br>

<code class="html"><span class="tag"><select><span class="tag">></span> <br><span class="tag"><optgroup>
<span class="aname"> label</span>=<span class="avalue">"自驾游"</span><span class="tag">></span> <span class="mlcom"><!--配合label标签给每组命名--></span> <br><span class="tag"><option>
<span class="tag">></span>省内<span class="tag"></span>
</option></span> <br><span class="tag"><option>
<span class="tag">></span>省外<span class="tag"></span>
</option></span> <br><span class="tag"></span>
</optgroup></span> <br><span class="tag"><optgroup>
<span class="aname"> label</span>=<span class="avalue">"旅行社"</span><span class="tag">></span> <br><span class="tag"><option>
<span class="tag">></span>省内<span class="tag"></span>
</option></span> <br><span class="tag"><option>
<span class="tag">></span>省外<span class="tag"></span>
</option></span> <br><span class="tag"><option>
<span class="tag">></span>国外<span class="tag"></span>
</option></span> <br><span class="tag"></span>
</optgroup></span> <br><span class="tag"></span></select></span></code><br>    你如果对更多的xhtml标签感兴趣，可以考虑看一看《HTML和XHTML权威指南》这本书，你也能在网上找到电子版的。我看过英文影印版的，虽然是英文但也不是太难看懂。<br>    你要是知道其他很有用的标签告诉我们吧！