performSelector：@selector错误

Question

我试图让这个xcode项目工作但是当它达到这个方法时：

- (void)xmlReaderDidFinishedParsingDocument{
    [[[UIApplication sharedApplication] delegate] performSelector:@selector(setControllersBanner)];
}

显示以下错误：

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[RadioStationAppDelegate setControllersBanner]: unrecognized selector sent to instance 0x5e66940'

有人可以请告诉我为什么它会抛出此错误消息，提前感谢！