iOS 退出应用程序

退出应用程序，方法很简单，只是动画效果没有那么好。

- (void)exitApplication {

    AppDelegate *app = [UIApplication sharedApplication].delegate;

    UIWindow *window = app.window;

    [UIView animateWithDuration:1.0 animations:^{

        window.alpha = ;

    } completion:^(BOOL finished) {

        exit();

    }];

}