UI旋转变换视图

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    _window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];

    _window.backgroundColor = [UIColor whiteColor];

    [_window makeKeyAndVisible];

    

    //创建可变数组

    mutArray = [[NSMutableArray alloc] initWithCapacity:7];

    

    for (int i=0; i<7; i++) {

        //创建子视图

        UIView *view = [[UIView alloc] initWithFrame:CGRectMake(60, 200, 250, 250)];

        

        view.backgroundColor = [UIColor colorWithRed:arc4random()%10*0.1 green:arc4random()%10*0.1 blue:arc4random()%10*0.1 alpha:1];

        

        [_window addSubview:view];

        

        //取出数组中的最后一个元素（也就是最上层的视图）

        UIView *lastView = [mutArray lastObject];

        if (lastView != nil) {

            view.transform = CGAffineTransformScale(lastView.transform, .8, .8);

        }

        

        //将视图添加到数组中

        [mutArray addObject:view];

    }

    

    _index = 0;

    //开启定时器

    [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(timeAction:) userInfo:nil repeats:YES];

    

    return YES;

}

- (void)timeAction:(NSTimer *)time {

    _index ++;

    //取得所有视图进行旋转

    for (UIView *view in mutArray) {

        

        //开始动画

        [UIView beginAnimations:nil context:nil];

        //设置动画的时间

        [UIView setAnimationDuration:1];

        //设置加速方式

        [UIView setAnimationCurve:UIViewAnimationCurveLinear];

        

        view.transform = CGAffineTransformRotate(view.transform, M_PI/1.1);

        view.backgroundColor = [UIColor colorWithRed:arc4random()%10*0.1 green:arc4random()%10*0.1 blue:arc4random()%10*0.1 alpha:1];

        [UIView commitAnimations];

    }

    

    //当第十秒的时候移除视图

    if (_index == 10) {

        for (UIView *view in mutArray) {

            [view removeFromSuperview];

        }

    }