Question

我是Android开发的新手。我已经定义了一个带有服务的测试应用程序，我在其中声明了一个BroadcastReceiver来接收蓝牙事件 -

public class MyService extends Service
 {
  BluetoothEventsReceiver mBluetoothEventsReceiver = null;

   @Override
    public int onStartCommand(Intent i, int flags, int startId) {

        // register the receiver to listen for Bluetooth Connected/Dis-connected events
        if (mBluetoothEventsReceiver != null) {
            mBluetoothEventsReceiver = new BluetoothEventsReceiver();

            Log.e(TAG, "Register receiver=" + mBluetoothEventsReceiver);
            IntentFilter intent = new IntentFilter("android.bluetooth.device.action.ACL_CONNECTED");
            intent.addAction("android.bluetooth.device.action.ACL_DISCONNECTED");

            getApplicationContext().registerReceiver(mBluetoothEventsReceiver, intent);
        }

        return super.onStartCommand(i, flags, startId);
   }
    @Override
    public IBinder onBind(Intent intent) {
        return null; 
    }
}

我的BroadcastReceiver定义为

public class BluetoothEventsReceiver extends BroadcastReceiver {

 public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();

        if (BluetoothDevice.ACTION_ACL_DISCONNECTED.equals(action)) {
            Log.e(TAG, "Received Event" + " ACTION_ACL_DISCONNECTED" );
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            Log.e(TAG, "device=" + device);        

        } else if (BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) {
            Log.e(TAG, "Received Event" + " ACTION_ACL_CONNECTED" );
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            Log.e(TAG, "device=" + device);
        }
    }
}

我从我的Activity启动服务，我希望BroadcastReceiver在连接和断开蓝牙耳机时打印日志消息，但不打印日志。所以，我猜它没有被称为。

public class MyActivity extends Activity {

    // Debugging
    public final static String TAG ="MyActivity";

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Log.e(TAG, "Starting service");
        startService(new Intent(".MyService"));

    }

此外，当我将接收器添加到Manifest文件时，然后调用BluetoothEventsReceiver。但根据我的理解，我不需要在Manifest文件中声明接收器，如果我希望接收器仅在服务运行时才处于活动状态。

我确实在清单文件中设置了权限

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.example"
          android:versionCode="1"
          android:versionName="1.0">
    <uses-sdk android:minSdkVersion="8"/>

    <uses-permission android:name="android.permission.BLUETOOTH" />
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

    <application android:label="@string/app_name">
        <activity android:name="MyActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>

        <service android:name=".MyService" android:process=":remote">
        <intent-filter>
            <!-- These are the interfaces supported by the service, which
        you can bind to. -->
            <action android:name=".MyService" />
        </intent-filter>
        </service>
</application>
</manifest>

请帮助调试我做错了什么。

Answer 1

更改您的意图过滤器：

IntentFilter intent = new IntentFilter("android.bluetooth.device.action.ACL_CONNECTED");
intent.addAction("android.bluetooth.device.action.ACL_DISCONNECTED");

到此：

 IntentFilter intent = new IntentFilter();
 intent.addAction("android.bluetooth.device.action.ACL_CONNECTED");
 intent.addAction("android.bluetooth.device.action.ACL_DISCONNECTED");

您创建的过滤器似乎与蓝牙意图不匹配，因为它们确实附加了额外的数据，而您的过滤器仅适用于只有一个操作的空意图。

以下是API的javadoc：

public IntentFilter（String action）自：API级别1 新的IntentFilter匹配单个操作而没有数据。如果随后未指定数据特征，则过滤器将仅匹配不包含数据的意图。

Answer 2

此startService(new Intent(".MyService"))无效。您需要提供Service类名称的实际路径。相对路径仅在AndroidManifest文件中使用，不应在代码中使用。

在您的活动中尝试以下内容：

Intent intent = new Intent(this, MyService.class);
this.startService(intent);

其中 MyService 是指服务的实际完全限定名称。

Android：BroadcastReceiver没有从我的服务中调用

2 个答案: