label標籤使用詳解

label：

The <label> tag defines a label for an input element.

label用來爲 input 元素定義標註（標記）。

The label element does not render as anything special for the user. However, it provides a usability improvement for mouse users, because if the user clicks on the text within the label element, it toggles the control.

label 元素不會向用戶呈現任何特殊效果。不過，它爲鼠標用戶改進了可用性。如果您在 label 元素內點擊文本，就會觸發此控件。就是說，當用戶選擇該標籤時，瀏覽器就會自動將焦點轉到和標籤相關的表單控件上。

The for attribute of the <label> tag should be equal to the id attribute of the related element to bind them together.

<label> 標籤的 for 屬性應當與相關元素的 id 屬性相同。

 

Optional Attributes

DTD indicates in which HTML 4.01/XHTML 1.0 DTD the attribute is allowed. S=Strict, T=Transitional, and F=Frameset.

Attribute	Value	DescriptionDTD
for	element_id	Specifies which form element a label is bound toSTF

 

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Standard Attributes

The <label> tag supports the following standard attributes:

Attribute	Value	DescriptionDTD
accesskey	character	Specifies a keyboard shortcut to access an element	STF
class	classname	Specifies a classname for an element	STF
dir	rtl ltr	Specifies the text direction for the content in an element	STF
id	id	Specifies a unique id for an element	STF
lang	language_code	Specifies a language code for the content in an element	STF
style	style_definition	Specifies an inline style for an element	STF
title	text	Specifies extra information about an element	STF
xml:lang	language_code	Specifies a language code for the content in an element, in XHTML documents	STF

More information about Standard Attributes .

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Event Attributes

The <label> tag supports the following event attributes:

Attribute	Value	Description	DTD
onblur	script	Script to be run when an element loses focus	STF
onclick	script	Script to be run on a mouse click	STF
ondblclick	script	Script to be run on a mouse double-click	STF
onfocus	script	Script to be run when an element gets focus	STF
onmousedown	script	Script to be run when mouse button is pressed	STF
onmousemove	script	Script to be run when mouse pointer moves	STF
onmouseout	script	Script to be run when mouse pointer moves out of an element	STF
onmouseover	script	Script to be run when mouse pointer moves over an element	STF
onmouseup	script	Script to be run when mouse button is released	STF
onkeydown	script	Script to be run when a key is pressed	STF
onkeypress	script	Script to be run when a key is pressed and released	STF
onkeyup	script	Script to be run when a key is released	STF

 

 

Browser Support

The <label> tag is supported in all major browsers.

 

關於label的兼容性。如果label中的是文字那麼ie和firefox都是可以支持的。如果是圖片firefox工作正常，但是ie不可以。

解決方案：

1. 傳統的方法用js:

    <script type="text/javascript">
        var label=document.getElementsByTagName('label');
        for (i=0;i<label.length;i++) {
            label[i].onclick = function () {
            var labelFor=this.getAttribute('for')?this.getAttribute('for'):this.getAttribute('HTMLfor')+'';
           document.getElementById(labelFor).click();
         }
     }

2.  將圖片作爲label的背景

3. 用span來覆蓋整個li 

<form action="">
    <ul>
        <li>
            <label for="one"><img src="hl_logo.png" alt=""></label>
            <input type="text" id="one">
        </li>
        <li>
            <label for="two"><img src="hl_logo.png" alt=""></label>
            <textarea cols="10" rows="3" id="two"></textarea>
        </li>
        <li>
            <label for="three"><img src="hl_logo.png" alt=""></label>
            <input type="checkbox" id="three">
        </li>
        <li>
            <label for="four"><img src="hl_logo.png" alt=""></label>
            <input type="radio" name="foo" id="four">
        </li>
        <li>
            <label for="five"><img src="hl_logo.png" alt=""></label>
            <input type="radio" name="foo" id="five">
        </li>
    </ul>
    </form>

       

li {


    overflow: hidden;


    display: inline-block; /* gives layout for IE float clearing */


}


li { display: block; }




label {


    float: left;


    position: relative;


    overflow: hidden;


}




label span {


    position: absolute;


    left: 0;


    top: 0;


    width: 500px;


    height: 500px;


    background: url(hl_logo.png) no-repeat -5000px; /* required for IE click bug fix */


}






例子來自於：http://haslayout.net/css/Image-Label-Focus-Bug