理解能力较差 有地方不懂以已标明 希望高手解释或推荐读物jscript


Type.registerNamespace("Demo");    //怎样看这个类Type的代码// Constructor
Demo.HoverButton = function(element) {    Demo.HoverButton.initializeBase(this, [element]);    this._clickDelegate = null;
    this._hoverDelegate = null;
    this._unhoverDelegate = null;
}
Demo.HoverButton.prototype = {    // text property accessors.
    get_text: function() {
        return this.get_element().innerHTML;        //首先是这里 this.get_element()  在哪里定义 是继承来的吗 如果是继承来的 怎样能看到它的定义  
    },
    set_text: function(value) {
        this.get_element().innerHTML = value;
    },    // Bind and unbind to click event.
    add_click: function(handler) {
        this.get_events().addHandler('click', handler);
    },
    remove_click: function(handler) {
        this.get_events().removeHandler('click', handler);
    },    // Bind and unbind to hover event.
    add_hover: function(handler) {
        this.get_events().addHandler('hover', handler);
    },
    remove_hover: function(handler) {
        this.get_events().removeHandler('hover', handler);
    },    // Bind and unbind to unhover event.
    add_unhover: function(handler) {
        this.get_events().addHandler('unhover', handler);
    },
    remove_unhover: function(handler) {
        this.get_events().removeHandler('unhover', handler);
    },    // Release resources before control is disposed.
    dispose: function() {        var element = this.get_element();     //这里？？？        if (this._clickDelegate) {
            Sys.UI.DomEvent.removeHandler(element, 'click', this._clickDelegate);
            delete this._clickDelegate;
        }        if (this._hoverDelegate) {
            Sys.UI.DomEvent.removeHandler(element, 'focus', this._hoverDelegate);
            Sys.UI.DomEvent.removeHandler(element, 'mouseover', this._hoverDelegate);
            delete this._hoverDelegate;
        }        if (this._unhoverDelegate) {
            Sys.UI.DomEvent.removeHandler(element, 'blur', this._unhoverDelegate);
            Sys.UI.DomEvent.removeHandler(element, 'mouseout', this._unhoverDelegate);
            delete this._unhoverDelegate;
        }
        Demo.HoverButton.callBaseMethod(this, 'dispose');
    },    initialize: function() {        var element = this.get_element();        if (!element.tabIndex) element.tabIndex = 0;        if (this._clickDelegate === null) {
            this._clickDelegate = Function.createDelegate(this, this._clickHandler);
        }
        Sys.UI.DomEvent.addHandler(element, 'click', this._clickDelegate);        if (this._hoverDelegate === null) {
            this._hoverDelegate = Function.createDelegate(this, this._hoverHandler);
        }
        Sys.UI.DomEvent.addHandler(element, 'mouseover', this._hoverDelegate);
        Sys.UI.DomEvent.addHandler(element, 'focus', this._hoverDelegate);        if (this._unhoverDelegate === null) {
            this._unhoverDelegate = Function.createDelegate(this, this._unhoverHandler);
        }
        Sys.UI.DomEvent.addHandler(element, 'mouseout', this._unhoverDelegate);
        Sys.UI.DomEvent.addHandler(element, 'blur', this._unhoverDelegate);        Demo.HoverButton.callBaseMethod(this, 'initialize');    },
    _clickHandler: function(event) {
        var h = this.get_events().getHandler('click');
        if (h) h(this, Sys.EventArgs.Empty);
    },
    _hoverHandler: function(event) {
        var h = this.get_events().getHandler('hover');
        if (h) h(this, Sys.EventArgs.Empty);
    },
    _unhoverHandler: function(event) {
        var h = this.get_events().getHandler('unhover');
        if (h) h(this, Sys.EventArgs.Empty);
    }
}
Demo.HoverButton.registerClass('Demo.HoverButton', Sys.UI.Control);    //这里是继承吧  sys.UI.Control   从哪来的  // Since this script is not loaded by System.Web.Handlers.ScriptResourceHandler
// invoke Sys.Application.notifyScriptLoaded to notify ScriptManager 
// that this is the end of the script.
if (typeof(Sys) !== 'undefined') Sys.Application.notifyScriptLoaded();
总之希望大家能解释的越详细越好  如果忙的话 推荐小弟两本看完就能理解上面的书  谢谢各位了