目标C：远程使计时器无效

Question

How do I invalidate a timer in one method when another method is called? Basically when tapFig is called, I want it to send a message to moveStickFig to invalidate the timer

-(void) moveStickFig:(NSTimer *)timer {
    UIButton *stick = (UIButton *)timer.userInfo;
    CGPoint oldPosition = stick.center;
    stick.center = CGPointMake(oldPosition.x + 1 , oldPosition.y);
    if (oldPosition.x == 900) {
        [stick removeFromSuperview];
        healthCount--;
        NSLog(@"%d", healthCount);
        [healthBar setImage:[UIImage imageNamed:[NSString stringWithFormat:@"health%d.png",healthCount]]];
    }
}

-(void) tapFig:(id)sender {
    UIButton *stick = (UIButton *)sender;
    count++;
    score.text = [NSString stringWithFormat:@"%d", count];
    [stick removeFromSuperview];
    [stick release];
}

Answer 1

I think you need a flag in moveStickFig that sets to true when tapFig is called.

-(void) moveStickFig:(NSTimer *)timer
{
    if( isTimerInvalidateSet )
    {
        [ self timer:invalidate ];
        return;
    }
    // ......
}

// you need to pass the same timer instance to `tapFig` that you earlier passed to `moveStickFig`.

-(void) tapFig:(id)sender
{
    isTimerInvalidateSet = true;
    [ self moveStickFig:theTimerInstance ] ; // theTimerInstance is same as earlier you passed to `moveStickFig`

    isTimerInvalidateSet = false;
    // ......
}

Note: Usually, you will set the timer to call a function repeatedly at a fixed frames per second. The timer does the job of calling it at that rate. There is no need of passing timer instance repeatedly. If that is what you want, then OK. However, if you need your game logic to be continued, you need to reset the isTimerInvalidateSet to false. Hope this helps !