定义方法后，为什么会收到“无法识别的选择器发送到实例”错误？

Question

I'm building an iOS (5.1) app on Xcode (4.4.1), and I'm almost done with the first phase of development, but I'm stuck on the final line of code. I've been using Kumulos as a backend & API solution, and at the moment all the API is working fine except for this bit:

Kumulos* k = [[Kumulos alloc]init];
[k setDelegate:self];
[k createNewTimePointWithJourneyIDFK:[journeyID integerValue]
    andTime:currentDate andLat:[lat floatValue] andLon:[lon floatValue]];

When it hits the createNewTimePointWithJourneyIDFK: method, it terminates. In the log it mentions this method and says an unrecognised selector was sent to an instance.

Now I realise this question has been asked a million times on SO, but I've 1) checked that the method has been defined, and 2) that it has been called correctly (or at least to the best of my knowledge). The way I've done the above is the way I've done the rest of the API calls, and they work well, so I can't see what the problem is. Very frustrating, I've spent hours on this last line! So please don't think I've come hear after a few minutes of not knowing what to do.

The error message

2012-08-11 22:36:58.769 busApp4Kumulos[5485:707] -[Kumulos
createNewTimePointWithJourneyIDFK:andTime:andLat:andLon:]:
unrecognizedselector sent to instance 0x3d1b70 2012-08-11 22:36:58.778
busApp4Kumulos[5485:707]
*** Terminating app due to uncaught exception
'NSInvalidArgumentException', reason: '-[Kumulos
createNewTimePointWithJourneyIDFK:andTime:andLat:andLon:]:
unrecognized selector sent to instance 0x3d1b70'
*** First throw call stack:
(0x35add88f 0x37e84259 0x35ae0a9b 0x35adf915 0x35a3a650 0x3ef5
0x37f86de3 0x37f86785 0x37f80e3f 0x35ab1b01 0x35ab112f 0x35ab0351
0x35a334a5 0x35a3336d 0x376cf439 0x3353fcd5 0x2dd9 0x2d74)
terminate called throwing an exception(lldb) 

The Method

This is located in the Kumulos.m file.

-(KSAPIOperation*) createNewTimePointWithJourneyIDFK:(NSInteger)journeyIDFK
     andTime:(NSDate*)time andLat:(float)lat andLon:(float)lon{

 NSMutableDictionary* theParams = [[NSMutableDictionary alloc]init];
        [theParams setValue:[NSNumber numberWithInt:journeyIDFK] forKey:@"journeyIDFK"];
                [theParams setValue:time forKey:@"time"];
                [theParams setValue:[NSNumber numberWithFloat:lat] forKey:@"lat"];
                [theParams setValue:[NSNumber numberWithFloat:lon] forKey:@"lon"];

KSAPIOperation* newOp = [[KSAPIOperation alloc]initWithAPIKey:theAPIKey
     andSecretKey:theSecretKey andMethodName:@"createNewTimePoint"
     andParams:theParams];
[newOp setDelegate:self];
[newOp setUseSSL:useSSL];

//we pass the method signature for the kumulosProxy callback on this thread

[newOp setCallbackSelector:@selector( kumulosAPI: apiOperation: createNewTimePointDidCompleteWithResult:)];
[newOp setSuccessCallbackMethodSignature:[self methodSignatureForSelector:@selector(apiOperation: didCompleteWithResult:)]];
[newOp setErrorCallbackMethodSignature:[self methodSignatureForSelector:@selector(apiOperation: didFailWithError:)]];
[opQueue addOperation:newOp];

return newOp;
}

Answer 1

The only thing I can think of is that something got stale in your project. Have you tried cleaning (via Product → Clean ) and rebuilding?