如何知道iOS设备何时插入？

Question

有没有办法知道我的设备（iPhone）何时插入电源，例如带有USB端口的电脑或汽车音响系统？我在我的应用中使用本地化服务，并且我想在设备插入时自动更改为kCLLocationAccuracyBestForNavigation。谢谢...

Answer 1

您可以注册以在配件连接或断开连接时收到通知。

例子：

[[EAAccessoryManager sharedAccessoryManager] registerForLocalNotifications]; 
NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter]; 
[notificationCenter addObserver:self 
         selector:@selector(accessoryDidConnect:) 
          name:EAAccessoryDidConnectNotification 
         object:nil]; 
[notificationCenter addObserver:self 
         selector:@selector(accessoryDidDisconnect:) 
          name:EAAccessoryDidDisconnectNotification 
         object:nil]; 

一旦你收到此通知，您可以使用一个for循环遍历每个附件，如：

NSArray *accessories = [[EAAccessoryManager sharedAccessoryManager] connectedAccessories]; 
EAAccessory *accessory = nil; 

for (EAAccessory *obj in accessories) 
{ 
    // See if you're interested in this particular accessory 
} 

在某一点（的dealloc也许）你将要注销为这些通知。你可以做到这一点，如：

NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter]; 
[notificationCenter removeObserver:self 
           name:EAAccessoryDidDisconnectNotification 
          object:nil]; 
[notificationCenter removeObserver:self 
           name:EAAccessoryDidConnectNotification 
          object:nil]; 
[[EAAccessoryManager sharedAccessoryManager] unregisterForLocalNotifications]; 

Answer 2

您可以启用电池监控直通的UIDevice class并检查电池状态，看它是否正在充电：

typedef enum { 
    UIDeviceBatteryStateUnknown, 
    UIDeviceBatteryStateUnplugged, 
    UIDeviceBatteryStateCharging, 
    UIDeviceBatteryStateFull, 
} UIDeviceBatteryState; 

你要检查或收费在启用最佳GPS准确性之前已满。通过让你自己的操作方法batteryStateChanged通话

UIDeviceBatteryState batteryState = [[UIDevice currentDevice] batteryState]; 

要订阅通知，关于电池状态的变化，例如：

- (void) setup { 
    [[UIDevice currentDevice] setBatteryMonitoringEnabled:YES]; 
    NSNotificationCenter * center= [NSNotificationCenter defaultCenter]; 
    [center addObserver:self 
      selector:@selector(batteryStateChanged) 
       name:UIDeviceBatteryStateDidChangeNotification 
       object:nil]; 
} 

Answer 3

要检查电池状态记得取消订阅当你的对象是dealloced：

- (void) dealloc 
{ 
    [[NSNotificationCenter defaultCenter] removeObserver:self]; 
    [[UIDevice currentDevice] setBatteryMonitoringEnabled:NO]; 
}