Objective c 知道系统何时在额外菜单中进入睡眠状态？

我为Mac开发了一个额外菜单（menulet），但我想知道使用额外菜单的机器是否已进入睡眠状态。我实现了一个snooze函数，但由于它是基于时间的方法，所以它相当不可靠。任何提示或建议将不胜感激

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谢谢

您可能想签出

NSWorkspaceWillSleepNotification

in.
诀窍是，您需要在NSWorkspace的notificationCenter上注册通知，而不是默认通知

示例代码：

- (void) receiveSleepNote: (NSNotification*) note
{
    NSLog(@"receiveSleepNote: %@", [note name]);
}

- (void) fileNotifications
{
    // These notifications are filed on NSWorkspace's notification center, not the default 
    // notification center. You will not receive sleep/wake notifications if you file 
    // with the default notification center.
    [[[NSWorkspace sharedWorkspace] notificationCenter] addObserver:self 
            selector:@selector(receiveSleepNote:) 
            name: NSWorkspaceWillSleepNotification object:nil];
}