NSInvocation: unrecognized selector though it is set

Question

I'm getting this message:

"(null): unrecognized selector sent to class 0x3f52e824"

The basic code I've tried:

SEL sel = @selector(applyProperties:toObject:);

NSInvocation* inv = [NSInvocation invocationWithMethodSignature:[self methodSignatureForSelector:sel]];
[inv setTarget:self];
[inv setSelector:sel];
[inv setArgument:params atIndex:0];
[inv setArgument:theObject atIndex:1];

NSOperationQueue* queue = [[NSOperationQueue alloc] init];
NSInvocationOperation* operation = [[NSInvocationOperation alloc] initWithInvocation:inv];
[queue addOperation:operation];

 [queue release];

I can call (applyProperties:toObject) by itself with these arguments... so I'm not sure what I'm doing wrong.

@jacob Yes, it's an instance method. I can and sometimes do call [self applyProperties:params toObject:theObject] as in the above code. — michael, Feb 08 '11 at 20:24

score 4 · Accepted Answer · answered Mar 11 '11 at 19:28

4

The answer is obvious, and was easy to miss in the documentation by vice of reading too quickly. Arguments 0 and 1 are reserved, so I solved by setting to indexes 2 and 3

answered Mar 11 '11 at 19:28

michael

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NSInvocation: unrecognized selector though it is set

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