我正在向ContentHlaceHolder中的PlaceHolder动态添加控件
var t = (ContentPlaceHolder)Master.FindControl("ContentPlaceHolder1");
var t1 = (PlaceHolder)mpContentPlaceHolder.FindControl("PlaceHolderName");
var t2 = (DropDownList)t1.FindControl("ControlID");
看起来我错过了一些东西,因为t2总是为空