Hide a UIlabel after some seconds

Question

I'm using this following code to hide a UILabel after some seconds. Unfortunately if the user close the view during the NSInvocation is in progress the app crashes

- (void)showStatusBarwithText:(NSString*)text{
    lblNotification.hidden=NO;
    NSInvocation* invoc = [NSInvocation invocationWithMethodSignature:[lblNotification methodSignatureForSelector:@selector(setHidden:)]];
    [invoc setTarget:lblNotification];
    [invoc setSelector:@selector(setHidden:)];
    lblNotification.text=text;
    BOOL yes = YES;
    [invoc setArgument:&yes atIndex:2];
    [invoc performSelector:@selector(invoke) withObject:nil afterDelay:1];

}

and that's the error

 *** -[UILabel setHidden:]: message sent to deallocated instance 0x1a8106d0

How can I solve? I have tried using

[NSObject cancelPreviousPerformRequestsWithTarget:lblNotification]

In the - (void)viewDidDisappear:(BOOL)animated but it doesn't work.

Answer 1

Here is how you should use performSelector

- (void)showStatusBarwithText:(NSString*)text{
   lblNotification.hidden=NO;
   [self performSelector:@selector(hideLabel) withObject:nil afterDelay:1];//1sec
}


-(void)hideLabel{
  lblNotification.hidden= YES;
}

or with the timer

[NSTimer scheduledTimerWithTimeInterval:1//1sec
                                 target:self
                               selector:@selector(hideLabel)
                               userInfo:nil
                                repeats:NO];