android - 蓝牙 ACTION_FOUND broadcastReceiver 不工作

Question

我正在尝试计算蓝牙 RSSI 并找到了一些示例，但是 broadcastReceiver 不工作。代码是这样的:

private final BroadcastReceiver receiver = new BroadcastReceiver(){

    @Override
    public void onReceive(Context context, Intent intent) {

        String action = intent.getAction();
        if(BluetoothDevice.ACTION_FOUND.equals(action)) {
            int rssi = intent.getShortExtra(BluetoothDevice.EXTRA_RSSI,Short.MIN_VALUE);
            String name = intent.getStringExtra(BluetoothDevice.EXTRA_NAME);
            TextView rssi_msg = (TextView) findViewById(R.id.textView1);
            rssi_msg.setText(rssi_msg.getText() + name + " => " + rssi + "dBm\n");
        }
    }
};

通过这个注册:

registerReceiver(receiver, new IntentFilter(BluetoothDevice.ACTION_FOUND));

当按钮被点击时，BTAdapter.startDiscovery();正在工作中。但是在 textview 中没有任何变化。

你能给我一些建议吗？

再次编辑:我稍微更改了我的代码，我将展示我的整个代码。

public class Blutooth extends Activity {

private BluetoothAdapter BTAdapter = BluetoothAdapter.getDefaultAdapter();

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_blutooth);

    Button boton = (Button) findViewById(R.id.button1);
    boton.setOnClickListener(new OnClickListener(){
        public void onClick(View v) {
            BTAdapter.startDiscovery();
        }
    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.blutooth, menu);
    return true;
  }
}

接收者类是

public class TestReceiver extends BroadcastReceiver {

@Override
public void onReceive(Context context, Intent intent) {
    // TODO Auto-generated method stub
    String name = intent.getAction();
    String device = intent.getStringExtra(BluetoothDevice.EXTRA_NAME);
    String rssi_msg = Integer.toString(intent.getShortExtra(BluetoothDevice.EXTRA_RSSI,Short.MIN_VALUE));
    Toast.makeText(context, name, Toast.LENGTH_SHORT).show();
  }

}

我正在尝试 Toast intent.getAction(); 但什么也没发生。我认为 BluetoothDevice.ACTION_FOUND 没有广播。

再次编辑:我使用的是android 6.0版本。我的整个 list 是这样的:

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

    <uses-feature android:name="android.hardware.bluetooth" />
    <uses-permission android:name="android.permission.BLUETOOTH" />
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-sdk
        android:minSdkVersion="23"
        android:targetSdkVersion="23" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".Blutooth"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <receiver android:name=".TestReceiver">
            <intent-filter>
                <action android:name="BluetoothDevice.ACTION_FOUND">
            </action></intent-filter>
        </receiver> 
    </application>

</manifest>

我听说 6.0 版本以上需要额外的权限才能使用 ACTION_FOUND。因此，我添加了 ACCESS_FINE_LOCATION 和 ACCESS_COARSE_LOCATION。我在 Activity 中添加了 filter.addAction(BluetoothDevice.ACTION_NAME_CHANGED); 代码。ACTION_NAME_CHANGED 运行良好，我可以获得 BluetoothDevice.EXTRA_NAME。但是 BluetoothDevice.EXTRA_RSSI,Short.MIN_VALUE 不工作。它打印默认值 -32768。BluetoothDevice.ACTION_FOUND 仍然不工作。

Answer 1

我终于找到了答案。Android 6.0 需要额外的权限，但仅向 Manifest 添加 uses-permission 是行不通的。您必须检查用户权限。我这样写我的代码:

int permissionCheck = ContextCompat.checkSelfPermission(thisActivity, Manifest.permission.ACCESS_COARSE_LOCATION);

        BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        if (!bluetoothAdapter.isEnabled())
          bluetoothAdapter.enable();
        leScanner = bluetoothAdapter.getBluetoothLeScanner();

        Button boton = (Button) findViewById(R.id.button1);
        boton.setOnClickListener(new OnClickListener(){
            public void onClick(View v) {
                leScanner.startScan(scanCallback);
            }
        });

此代码显示权限弹出窗口。感谢您的许多回答。