background-position Attribute | backgroundPosition参数属性

Sets or retrieves the position of the background of the object.

dhtml语法

HTML { background-position : sPosition }
Scripting object.style.backgroundPosition [ = sPosition ]

DHTML可能的值

sPosition String that specifies or receives one or two of the following values.
length Floating-point number, followed by an absolute units designator (cm, mm, in, pt, pc, or px) or a relative units designator (em or ex). For more information about the supported length units, see css length units reference.
percentage integer, followed by a percent sign (%). the value is a percentage of the width or height of the object.
vAlignment Vertical alignment value. Possible values include the following:
top Vertical alignment is at the top.
center Vertical alignment is centered.
bottom Vertical alignment is at the bottom.
hAlignment Horizontal alignment value. Possible values include the following:
left Horizontal alignment is to the left.
center Horizontal alignment is centered.
right Horizontal alignment is to the right.
The property is read/write. The property has a default value of 0% 0%. The Cascading Style Sheets (CSS) attribute is not inherited.
Expressions can be used in place of the preceding value(s), as of Microsoft® Internet Explorer 5. For more information, see about dynamic properties.

remarks

if only one value is set, that value applies to the horizontal coordinate, and the vertical is set to 50%. if both values are set, the first value applies to the horizontal coordinate and the second value applies to the vertical.
setting the values to 0% 0% positions the backgroundimage to the upper left corner of the element's content excluding the padding.
specifying right center has the following effect: because right is assumed to be an x-coordinate direction, right overwrites the center value, and the background shifts right accordingly.
this property can be set with the other background properties using the background composite property.

Examples

The following examples use the background-position attribute and the backgroundPosition property to specify the position of a background image.
This example uses a call to an embedded (global) style sheet to move the sphere.
<STYLE>
.style1 { background-position:top center }
.style2 { background-position:bottom right }
</STYLE>
</HEAD>
<BODY onload="oSpan.className='style1'">
<SPAN STYLE="font-size:14; width:250;" ID="oSpan"
onmouseover="this.className='style2'" onmouseout="this.className='style1'">
. . . </SPAN>
This feature requires Microsoft® Internet Explorer 4.0 or later. Click the following icon to install the latest version. Then reload this page to view the sample.
This example uses an inline style to move the sphere.
<SPAN onmouseover="this.style.backgroundPosition='bottom right'">
This feature requires Microsoft® Internet Explorer 4.0 or later. Click the following icon to install the latest version. Then reload this page to view the sample.

是否符合公共标准

This property is defined in Cascading Style Sheets (CSS), Level 1 (CSS1) .

Applies To

A, ADDRESS, B, BIG, BLOCKQUOTE, BODY, BUTTON, CAPTION, CENTER, CITE, CODE, COL, COLGROUP, CUSTOM, DD, defaults, DFN, DIR, DIV, DL, DT, EM, FIELDSET, FORM, hn, HTML, I, IMG, INPUT type=button, INPUT type=checkbox, INPUT type=file, INPUT type=image, INPUT type=password, INPUT type=radio, INPUT type=reset, INPUT type=submit, INPUT type=text, ISINDEX, KBD, LABEL, LEGEND, LI, LISTING, MARQUEE, MENU, OL, P, PLAINTEXT, PRE, runtimeStyle, S, SAMP, SMALL, SPAN, STRIKE, STRONG, style, SUB, SUP, TABLE, TBODY, TD, TEXTAREA, TFOOT, TH, THEAD, TR, TT, U, UL, VAR, XMP