<col>
=====

**HTML `<col>` 元素** 定义表格中的列，并用于定义所有公共单元格上的公共语义。它通常位于`<colgroup>`元素内。

此元素允许使用 CSS 进行样式列，但只有少数属性将对该列产生影响（请参阅列表的CSS 2.1 规范）。

|  |  |
| --- | --- |
| Content categories | None. |
| Permitted content | None; it is a void element. |
| Tag omission | It must have start tag, but must not have an end tag. |
| Permitted parents | `<colgroup>` only, though it can be implicitly
 defined as its start tag is not mandatory. The
 `<colgroup>` must not have a
 `span` attribute.
  |
| Implicit ARIA role | No corresponding role |
| Permitted ARIA roles | No `role` permitted |
| DOM interface | `HTMLTableColElement` (en-US) |

属性
--

该元素包含一些全局属性 全局属性 (en-US).

`align` 
已弃用

This enumerated attribute specifies how horizontal alignment of each column cell content will be handled. Possible values are:

* `left`, aligning the content to the left of the cell
* `center`, centering the content in the cell
* `right`, aligning the content to the right of the cell
* `justify`, inserting spaces into the textual content so that the content is justified in the cell
* `char`, aligning the textual content on a special character with a minimal offset, defined by the `char` and `charoff` attributes 未实现 (查看 Firefox bug 2212).If this attribute is not set, its value is inherited from the `align` of the `<colgroup>` element this `<col>` element belongs too. If there are none, the `left` value is assumed.

**备注：** Do not use this attribute as it is obsolete (not supported) in the latest standard.
 To achieve the same effect as the `left`, `center`, `right` or `justify` values:


* Do not try to set the `text-align` property on a selector giving a `<col>` element. Because `<td>` (en-US) elements are not descendant of the `<col>` element, they won't inherit it.
* If the table doesn't use a `colspan` (en-US) attribute, use the `td:nth-child(an+b)` CSS selector where a is the total number of the columns in the table and b is the ordinal position of the column in the table. Only after this selector the `text-align` property can be used.
* If the table does use a `colspan` (en-US) attribute, the effect can be achieved by combining adequate CSS attribute selectors like `[colspan=n]`, though this is not trivial.
* To achieve the same effect as the `char` value, in CSS3, you can use the value of the `char` as the value of the `text-align` property 未实现.

`bgcolor` 
非标准

定义列中对应的每个单元格的背景色。其值是 sRGB 定义的 6 位 16 进制代码之一，前缀为 '#'。也可以使用以下 16 个预定义的颜色字符

注意：不要使用这个属性，它是非标准的，并且只实现了 IE 浏览器中的部分版本：`<col>` 元素的样式应该使用 CSS. 在`<td>` (en-US)元素上使用 CSS 的 `background-color` 属性即可实现相同效果。

`char` 
已弃用

This attribute is used to set the character to align the cells in a column on. Typical values for this include a period (.) when attempting to align numbers or monetary values. If `align` is not set to `char`, this attribute is ignored.

**备注：** Do not use this attribute as it is obsolete (and not supported) in the latest standard. To achieve the same effect as the `char`, in CSS3, you can use the character set using the `char` attribute as the value of the `text-align` property 未实现.

`charoff` 
已弃用

This attribute is used to indicate the number of characters to offset the column data from the alignment characters specified by the **char** attribute.

**备注：** Do not use this attribute as it is obsolete (and not supported) in the latest standard.

`span`

该属性值为一个正整数，表示该 <col> 元素横跨的列数。默认值为 1

`valign` 
已弃用

This attribute specifies the vertical alignment of the text within each cell of the column. Possible values for this attribute are:

* `baseline`, which will put the text as close to the bottom of the cell as it is possible, but align it on the baseline of the characters instead of the bottom of them. If characters are all of the size, this has the same effect as `bottom`.
* `bottom`, which will put the text as close to the bottom of the cell as it is possible;
* `middle`, which will center the text in the cell;
* and `top`, which will put the text as close to the top of the cell as it is possible.

**备注：** Do not use this attribute as it is obsolete (and not supported) in the latest standard:

* Do not try to set the `vertical-align` property on a selector giving a `<col>` element. Because `<td>` (en-US) elements are not descendant of the `<col>` element, they won't inherit it.
* If the table doesn't use a `colspan` (en-US) attribute, use the `td:nth-child(an+b)` CSS selector where a is the total number of the columns in the table and b is the ordinal position of the column in the table. Only after this selector the `vertical-align` property can be used.
* If the table does use a `colspan` (en-US) attribute, the effect can be achieved by combining adequate CSS attribute selectors like `[colspan=n]`, though this is not trivial.

`width` 
已弃用

This attribute specifies a default width for each column in the current column group. In addition to the standard pixel and percentage values, this attribute might take the special form `0*`, which means that the width of each column in the group should be the minimum width necessary to hold the column's contents. Relative widths such as `0.5*` also can be used.

示例
--

详见 `<table>` 页面 `<col>` 标签的示例。

规范
--

| Specification |
| --- |
| HTML Standard # the-col-element |

浏览器兼容性
------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

相关链接
----

* Other table-related HTML Elements: `<caption>`, `<colgroup>`, `<table>`, `<tbody>`, `<td>` (en-US), `<tfoot>`, `<th>`, `<thead>`, `<tr>`;
* CSS properties and pseudo-classes that may be specially useful to style the `<col>` element:
    + the `width` property to control the width of the column;
    + the `:nth-child` pseudo-class to set the alignment on the cells of the column;
    + the `text-align` property to align all cells content on the same character, like '.'.