我收到了几份与iOS7中的UICollectionView相关的崩溃报告。我无法始终如一地重现此崩溃。ExceptionType:SIGSEGVExceptionCodes:SEGV_ACCERRat0x91c4392bCrashedThread:0ApplicationSpecificInformation:***Terminatingappduetouncaughtexception'',reason:''Thread0Crashed:0libobjc.A.dylib0x39dd2b26objc_msgSend+61UIKit0x31fd5eef-[UICollectionView