如何知道iOS設備何時插入？

Question

有沒有辦法知道我的設備（iPhone）何時插入電源，例如帶有USB端口的電腦或汽車音響系統？我在我的應用中使用本地化服務，並且我想在設備插入時自動更改爲kCLLocationAccuracyBestForNavigation。謝謝...

Answer 1

您可以註冊以在配件連接或斷開連接時收到通知。

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，您可以使用一個for循環遍歷每個附件，如：

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

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

在某一點（的dealloc也許）你將要註銷爲這些通知。你可以做到這一點，如：

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

Answer 2

您可以啓用電池監控直通的UIDevice class並檢查電池狀態，看它是否正在充電：

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

你要檢查或收費在啓用最佳GPS準確性之前已滿。通過讓你自己的操作方法batteryStateChanged通話

UIDeviceBatteryState batteryState = [[UIDevice currentDevice] batteryState]; 

要訂閱通知，關於電池狀態的變化，例如：

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

Answer 3

要檢查電池狀態記得取消訂閱當你的對象是dealloced：

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