onbeforeupdate Event

DHTML文档教程

---

Fires on a databound object before updating the associated data in the data source object.

dhtml语法

Inline HTML	<ELEMENT onbeforeupdate = "handler" ... >	All platforms
Event property	object.onbeforeupdate = handler	JScript only
	object.onbeforeupdate = GetRef("handler")	Visual Basic Scripting Edition (VBScript) 5.0 or later only
Named script	<SCRIPT FOR = object EVENT = onbeforeupdate>	Internet Explorer only

Event Information

Bubbles	Yes
Cancels	Yes
To invoke	Cause an object to receive focus, change the value of the object, and either cause the object to lose focus or force the page to unload.
Default action	Signals that the data contained in an object has changed.

Event Object Properties

Although event handlers in the DHTML Object Model do not receive parameters directly, a handler can query an event object for data.

available properties

altKey	Sets or retrieves a value that indicates the state of the ALT key.
altLeft	Sets or retrieves a value that indicates the state of the left ALT key.
cancelBubble	Sets or retrieves whether the current event should bubble up the hierarchy of event handlers.
clientX	Sets or retrieves the x-coordinate of the mouse pointer's position relative to the client area of the window, excluding window decorations and scroll bars.
clientY	Sets or retrieves the y-coordinate of the mouse pointer's position relative to the client area of the window, excluding window decorations and scroll bars.
ctrlLeft	Sets or retrieves the state of the left CTRL key.
offsetX	Sets or retrieves the x-coordinate of the mouse pointer's position relative to the object firing the event.
offsetY	Sets or retrieves the y-coordinate of the mouse pointer's position relative to the object firing the event.
returnValue	Sets or retrieves the return value from the event.
screenX	Retrieves the x-coordinate of the mouse pointer's position relative to the user's screen.
screenY	Sets or retrieves the y-coordinate of the mouse pointer's position relative to the user's screen.
shiftLeft	Retrieves the state of the left SHIFT key.
srcElement	Sets or retrieves the object that fired the event.
type	Sets or retrieves the event name from the event object.
x	Sets or retrieves the x-coordinate, in pixels, of the mouse pointer's position relative to a relatively positioned parent element.
y	Sets or retrieves the y-coordinate, in pixels, of the mouse pointer's position relative to a relatively positioned parent element.

Remarks

If the onbeforeupdate event is canceled, the onafterupdate event does not fire.

是否符合公共标准

There is no public standard that applies to this event.

Applies To

	A, BUTTON, DIV, FRAME, IFRAME, IMG, INPUT type=checkbox, INPUT type=hidden, INPUT type=password, INPUT type=radio, INPUT type=text, TEXTAREA, LABEL, LEGEND, MARQUEE, SELECT, SPAN, BDO, CUSTOM, RT, RUBY

更多语法参考

Introduction to Data Binding