如何以编程方式检查蓝牙是否已启用？

Question

我想定期检查是否在任何 Android 设备上启用了蓝牙。 是否有任何意图可以使用 BroadcastReceiver 来捕获，或者是否有其他方法可以做到这一点？

Answer 1

你去吧：

BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
    // Device does not support Bluetooth
} else if (!mBluetoothAdapter.isEnabled()) {
    // Bluetooth is not enabled :)
} else {
    // Bluetooth is enabled 
}

有uses-permission

 <uses-permission android:name="android.permission.BLUETOOTH" android:required="false" />

Answer 2

在这里，我有其他选择作为这个问题的答案。

首先在您的清单文件中添加以下几行。

<uses-feature android:name="android.hardware.BLUETOOTH" android:required="false"/>

现在，在您要检查蓝牙支持性的地方，请使用以下代码。

boolean isBluetoothSupported = getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH);

Answer 3

public boolean isBluetoothEnabled()
    {
        BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        return mBluetoothAdapter.isEnabled();

    }

具有清单文件中的权限：

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

Answer 4

要以编程方式检查蓝牙状态，开启或关闭：

    BluetoothAdapter btAdapter = ((Build.VERSION.SDK_INT > Build.VERSION_CODES.JELLY_BEAN_MR1)
           ?((BluetoothManager)mContext.getSystemService(Context.BLUETOOTH_SERVICE)).getAdapter()
               :(BluetoothAdapter.getDefaultAdapter()));

       if(btAdapter==null){
        return;
       }
       if(btAdapter.getState()==BluetoothAdapter.STATE_ON){
            //Bluetooth is ON
       }

您还可以收听 Intent 操作：

蓝牙适配器.ACTION_STATE_CHANGED

Answer 5

使用可以使用

BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

用于检查 bt 连接

mBluetoothAdapter.getProfileConnectionState(BluetoothHeadset.HEADSET) == BluetoothHeadset.STATE_CONNECTED

检查 bt 断开连接

mBluetoothAdapter.getProfileConnectionState(BluetoothHeadset.HEADSET) == BluetoothHeadset.STATE_DISCONNECTED

Answer 6

这就是我在@xjaphx 的回答的帮助下做到的，稍微简化的版本：

 private boolean getBlueToothOn(){
    BluetoothAdapter btAdapter = BluetoothAdapter.getDefaultAdapter(); 
      return btAdapter != null && btAdapter.isEnabled();
    }

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

Answer 7

首先允许来自清单的权限。

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

public class MainActivity extends AppCompatActivity {
    
    private BluetoothAdapter mAdapter;
    private BluetoothDevice mDevice;
    private static final int ACCESS_REQUEST_CODE=100;
    private static final int REQUEST_ENABLE_CODE=1;
    private AudioRecord mRecord;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (mAdapter!=null && mAdapter.isEnabled()){

        }
        else {
            Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableIntent, REQUEST_ENABLE_CODE);
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode==REQUEST_ENABLE_CODE){
            if (resultCode==RESULT_OK){
                println("Bluettoth Enabled");
            }
            else if (resultCode==RESULT_CANCELED){
                println("Bluetooth Not permitted");
                finish();
            }
        }
    }
}