这是我第一次以编程方式添加UI元素。该应用因错误而崩溃:2014-01-1418:39:50.080Convention[27580:70b]-[__NSCFConstantStringalignmentRectInsets]:unrecognizedselectorsenttoinstance0x10c0282014-01-1418:40:00.792Convention[27580:70b]***Terminatingappduetouncaughtexception'NSInvalidArgumentException',reason:'-[__NSCFConstantStrin