扩展easyUI tab控件，添加加载遮罩效果

(function () {  
    $.extend($.fn.tabs.methods, {  
        //显示遮罩  
        loading: function (jq, msg) {  
            return jq.each(function () {  
                var panel = $(this).tabs("getSelected");  
                if (msg == undefined) {  
                    msg = "正在加载数据，请稍候...";  
                }  
                $("<div class=\"datagrid-mask\"></div>").css({ display: "block", width: panel.width(), height: panel.height() }).appendTo(panel);  
                $("<div class=\"datagrid-mask-msg\"></div>").html(msg).appendTo(panel).css({ display: "block", left: (panel.width() - $("div.datagrid-mask-msg", panel).outerWidth()) / 2, top: (panel.height() - $("div.datagrid-mask-msg", panel).outerHeight()) / 2 });  
            });  
        }  
,  
        //隐藏遮罩  
        loaded: function (jq) {  
            return jq.each(function () {  
                var panel = $(this).tabs("getSelected");  
                panel.find("div.datagrid-mask-msg").remove();  
                panel.find("div.datagrid-mask").remove();  
            });  
        }  
    });  
})(jQuery);  

显示遮罩：$("#tabID").tabs("loading",msg) msg--要显示的信息

隐藏遮罩：$("#tabID").tabs("loaded")