Objective-Cハマった

NSObjectをNSDictionaryでキャストしてobjectForKeyメソッドで”question”のキーの文字列を取ろうとした

    self.questionText.text = [(NSDictionary *)[self.dataObject description] objectForKey:@"question"];

2012-06-03 15:38:37.993 pageTest[17477:f803] -[__NSCFString objectForKey:]: unrecognized selector sent to instance 0x6a3a2f0
2012-06-03 15:38:37.999 pageTest[17477:f803] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFString objectForKey:]: unrecognized selector sent to instance 0x6a3a2f0'
*** First throw call stack:
(0x13ca022 0x155bcd6 0x13cbcbd 0x1330ed0 0x1330cb2 0x2c30 0xdd38f 0xdd51f 0x132d4a5 0x132d026 0x132cf35 0xdd44d 0xdd51f 0x132d4a5 0x132d026 0x132cf35 0xdd44d 0xdd5eb 0xde4ed 0x4ba0c 0x50f92 0x4b14b 0x3a550 0x3a670 0x3a836 0x4172a 0x12596 0x13274 0x22183 0x22c38 0x16634 0x12b4ef5 0x139e195 0x1302ff2 0x13018da 0x1300d84 0x1300c9b 0x12c65 0x14626 0x1cad 0x1c15)
terminate called throwing an exception(lldb) 

description自体がNSStringを返すからだ
こうした

    self.questionText.text = [(NSDictionary *)self.dataObject objectForKey:@"question"];