iOS代碼退出程序一般直接調用exit(0); ，但是視覺上看起來像閃退，於是，我借鑒了下網上別人的代碼，寫了一個向下切出退出程序的方法，代碼如下：

- (void)exitApplication {
    AppDelegate *app = [UIApplication sharedApplication].delegate;
    UIWindow *window = app.window;
    
    [UIView animateWithDuration:1.0f animations:^{
        window.alpha = 0;
        window.frame = CGRectMake(0, window.bounds.size.width, 0, 0);
    } completion:^(BOOL finished) {
        exit(0);
    }];
    
}