退出iOS应用

iOS的SDK中提供了以下的API退出应用程序：

exit(0);

但是这种方法没有动画效果就直接退出程序，给用户的感觉是程序发生异常而退出了。

考虑到这种方式只是缺少退出时的动画效果，那么可以加上一个动画，动画完成后再调用exit退出程序。

- (void)exitApplication {
    [UIView beginAnimations:@"exitApplication" context:nil];
    [UIView setAnimationDuration:0.5];
    [UIView setAnimationDelegate:self];
    [UIView setAnimationTransition:UIViewAnimationCurveEaseOut forView:[UIApplication sharedApplication].keyWindow cache:NO];
    [UIView setAnimationDidStopSelector:@selector(animationFinished:finished:context:)];
    [UIApplication sharedApplication].keyWindow.bounds = CGRectMake(0, 0, 0, 0);
    [UIView commitAnimations];
}

- (void)animationFinished:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context {
    if ([animationID compare:@"exitApplication"] == 0) {
        exit(0);
    }
}