Question

I’m very new to IOS programming and i have doubt with NSThread.
My problem is, i have a UILabel in my view and i want to hide and make it visible Successively after every 5 second.
For this purpose i’ve used NSThread as below.

[NSThread detachNewThreadSelector:@selector(animate) toTarget:self withObject:nil];

    -(void) animate
    {
        while(animateLabel){
               [NSThread sleepForTimeInterval:5];
                if(label.hidden){
                    NSLog(@"Label is hidden");
                    [label setHidden:NO];
                }else
                 { 
                    NSLog(@"Label is vissible");
                   [label setHidden:YES];
                   }


  }
}

Now i’m getting “Label is hidden” and “Label is vissible” Successively in log after every 5 seconds. But my label is not getting hide.

I did with NSTimer and it’s working.

But, what is the problem with above code ?. If no problem with this code, Why NSThread couldn’t do ?

Answer 1

You need to perform this on a main thread instead.

Try this –

[NSThread performSelectorOnMainThread:@selector(animate) toTarget:self withObject:nil];

since you have while loop

remove sleep and add runloop

[[NSRunLoop currentRunLoop] runUntilDate:(NSDate*)]