USB設備拔出時停止服務

Question

我想在拔掉USB插頭時停止正在運行的服務。

我的活動onCreate裏面我查的意圖其action

if (getIntent().getAction().equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) { 
     Log.d(TAG, "************** USB unplugged stopping service **********"); 
     Toast.makeText(getBaseContext(), "usb was disconneced", Toast.LENGTH_LONG).show(); 
     stopService(new Intent(this, myService.class)); 
    } else { 
     init(); 
    } 

而且我manifest裏面我有另一個intent filter

 <intent-filter> 
      <action android:name="android.hardware.usb.action.USB_DEVICE_DETACHED" /> 
     </intent-filter> 

這intent filter以及它被調用。

 <intent-filter> 
      <category android:name="android.intent.category.DEFAULT" /> 

      <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" /> 
     </intent-filter> 

但是detach沒有被調用。

Answer 1

您需要註冊一個BroadcastReceiver

BroadcastReceiver receiver = new BroadcastReceiver() { 
     public void onReceive(Context context, Intent intent) { 
      if(intent.getAction().equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) { 
       Log.d(TAG, "************** USB unplugged stopping service **********"); 
       Toast.makeText(getBaseContext(), "usb was disconneced", 
        Toast.LENGTH_LONG).show(); 
        stopService(new Intent(this, myService.class)); 
      } 
     }; 

    IntentFilter filter = new IntentFilter(); 
    filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED); 
    registerReceiver(receiver, filter); 

Answer 2

嗯.. ACTION_USB_DEVICE_DETACHED當USB設備（不是電纜）從手機/平板電腦分開燒製。這不是你想要的。

我不知道是否有直接檢測USB電纜連接的API，但您可以使用ACTION_POWER_CONNECTED和ACTION_POWER_DISCONNECTED來實現您的目標。

使用下面爲您的接收機濾波器：

<intent-filter> 
    <action android:name="android.intent.action.ACTION_POWER_CONNECTED"/> 
    <action android:name="android.intent.action.ACTION_POWER_DISCONNECTED"/> 
</intent-filter> 

而在你的接收器，你可以檢查狀態並實現你想要的邏輯：

public class MyReceiver extends BroadcastReceiver { 
    @Override 
    public void onReceive(Context context, Intent intent) { 
     switch(intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1)) { 
      case 0: 
       // The device is running on battery 
       break; 
      case BatteryManager.BATTERY_PLUGGED_AC: 
       // Implement your logic 
       break; 
      case BatteryManager.BATTERY_PLUGGED_USB: 
       // Implement your logic 
       break; 
      case BATTERY_PLUGGED_WIRELESS: 
       // Implement your logic 
       break; 
      default: 
       // Unknown state 
     } 
    } 
}