rotate code

rotation.m

-(IBAction)startRotation:(id)sender
{
    if (rotateTimer) {
        [rotateTimer invalidate];
    }
    rotateTimer = [NSTimer scheduledTimerWithTimeInterval:0.01 target:self selector:@selector(rotate) userInfo:nil repeats:YES];
}

-(IBAction)stopRotation:(id)sender
{
    [rotateTimer invalidate];
    rotateTimer = nil;
    int accumulatedScore = 0;
    for (int i=0; i<[self.dataArray count]; i++) {
        accumulatedScore += [self.dataArray[i][@"score"] intValue];
        if (accumulatedScore > degree) {
            NSString *selectedItem = self.dataArray[i][@"name"];
            UIAlertController *ac = [UIAlertController alertControllerWithTitle:@"選到" message:selectedItem preferredStyle:UIAlertControllerStyleAlert];
            UIAlertAction *action = [UIAlertAction actionWithTitle:@"關閉" style:UIAlertActionStyleDefault handler:nil];
            [ac addAction:action];
            [self presentViewController:ac animated:YES completion:nil];
            break;
        }
    }
}