NSInvocation的使用

Sample Code:

            NSMethodSignature * signature = [[self class] instanceMethodSignatureForSelector:@selector(exportSelectedContactsToCsv)];

            NSInvocation * invocation = [NSInvocation invocationWithMethodSignature:signature];

            [invocation setTarget:self];

            [invocation setSelector:@selector(exportSelectedContactsToCsv)];

            [invocation invoke];