AJAX.NET CascadingDropDown 报错Error: 'Sys.Extended.UI' is null or not an object找不到什么原因呢 $create(Sys.Extended.UI.CascadingDropDownBehavior, {"Category":"countryID","ClientStateFieldID":"ctl00_main_CascadingDropDown1_ClientState","LoadingText":"加载中...","PromptText":"国家","ServiceMethod":"GetCountry","ServicePath":"../WebService.asmx","id":"ctl00_main_CascadingDropDown1"}, null, null, $get("ctl00_main_dropCountry"));
解决方案 »
免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货