探讨微软ASP.NET AJAX控件开发技术（客户端）

Type.registerNamespace('AjaxImageButtonNamespace');
AjaxImageButtonNamespace.MyCliImageButton = function(element)
{
this._hoverImageUrl = '';
this._originalImageUrl = '';
this._mouseOverHandler = null;
this._mouseOutHandler = null;
this._clickHandler = null;
AjaxImageButtonNamespace.MyCliImageButton.initializeBase(this, [element]);
}
AjaxImageButtonNamespace.MyCliImageButton.prototype =
{
get_hoverImageUrl : function(){
return this._hoverImageUrl;
},
set_hoverImageUrl : function(value) {
var e = Function._validateParams(arguments, [{name: 'value', type: String}]);
if (e) throw e;
if (this._hoverImageUrl != value)
{
this._hoverImageUrl = value;
this.raisePropertyChanged('hoverImageUrl');
}
},
initialize : function(){
AjaxImageButtonNamespace.MyCliImageButton.callBaseMethod(this, 'initialize');
var target = this.get_element();
this._originalImageUrl = target.src;
this._mouseOverHandler = Function.createDelegate(this, this._onMouseOver);
this._mouseOutHandler = Function.createDelegate(this, this._onMouseOut);
this._clickHandler = Function.createDelegate(this, this._onClick)
$addHandlers(target, {'mouseover':this._mouseOverHandler, 
'mouseout':this._mouseOutHandler, 'click': this._clickHandler}, this);
},
dispose : function(){
$clearHandlers(this.get_element()); 
delete this._mouseOverHandler;
delete this._mouseOutHandler;
delete this._clickHandler;
AjaxImageButtonNamespace.MyCliImageButton.callBaseMethod(this, 'dispose');
},
add_click : function(handler) {
this.get_events().addHandler('click', handler);
},
remove_click : function(handler) {
this.get_events().removeHandler('click', handler);
},
_onMouseOver : function(e) {
e.target.src = this._hoverImageUrl;
},
_onMouseOut : function(e) {
e.target.src = this._originalImageUrl;
},
_onClick : function(e) {
e.preventDefault();
var handler = this.get_events().getHandler('click');
if (handler != null) {
handler(this, Sys.EventArgs.Empty);
}
}
}
AjaxImageButtonNamespace.MyCliImageButton.registerClass
('AjaxImageButtonNamespace.MyCliImageButton', Sys.UI.Control);
if (typeof(Sys) != 'undefined') 
Sys.Application.notifyScriptLoaded();
}

    <script type="text/javascript">
function pageLoad(){
$create(AjaxImageButtonNamespace.MyCliImageButton, 
{'hoverImageUrl':'Images/updateh.gif'}, {'click':buttonClicked}, null, $get('cliBtn'));
}
function buttonClicked(sender, e) {
alert('I am clicked');
return false;
}
</script>

<asp:ScriptManager ID="ScriptManager1" runat="server" >
<Scripts>
<asp:ScriptReference Path="ImageButton.js" />
</Scripts>
</asp:ScriptManager>