Question

My method may not respond and I can’t get why

in ClassA.h:

@interface ClassA : NSObject {
    NSString *inStr;
    NSInteger *peak;
}
@property (retain,nonatomic)      NSString *inStr;
@end

in ClassA.m

 NSLog(@"%d peaks",peak);
                       peak++;
                       inStr = [NSString stringWithFormat:@"Peaks : %d",peak ];

                       [ClassB setUpdateLabel:inStr];

in ClassB.h

    @interface ClassB : NSObject {
            IBOutlet UILabel *peaksLabel;
            NSString *tempStr;
        }

    @property (nonatomic, retain)   UILabel             *peaksLabel;
    - (void) setUpdateLabel:(NSString*)inStr;
    @end

in ClassB.m

#import ClassB.h
@implementation classB;
-(void) setUpdateLabel:(NSString*)inStr{
    peaksLabel.text=inStr;

}

Anyone can help me ?

Answer 1

You are declaring - (void) setUpdateLabel:(NSString*)inStr; as a instance method, however you are using it as a class method.

‘-‘ indicates instance methods
‘+’ indicates class methods

If you want this to work you either change the declaration to + (void) setUpdateLabel:(NSString*)inStr; or you make an object of the Class B like this:

ClassB *obj = [[ClassB alloc] init];
[obj setUpdateLabel:@"Something"];

and remember to release it.