E / BluetoothAdapter：蓝牙活页夹为空

Question

hello I have a problem with the OnePlus6, this device is detected as having no bluetooth

here is the method that activates bluetooth:

protected void onResume(){
    super.onResume();
    boolean fAdapterEnabled = BluetoothAdapter.getDefaultAdapter().isEnabled();
    try {
        if (!fAdapterEnabled) {
            Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivity(intent);
        }
    }catch (Exception e){
        Log.d("bgx_dbg", "Exception caught while calling isEnabled.");
        Toast.makeText(this,"Exception caught", Toast.LENGTH_LONG).show();
    }
}

I want to clarify this code works perfectly with another smartphone

here is the mistake I have:

2019-01-25 14:16:57.571 28761-28761/? E/BluetoothAdapter: Bluetooth binder is null 2019-01-25 14:16:57.590 28761-28761/? E/AndroidRuntime: FATAL EXCEPTION: main Process: com.clj.blesample, PID: 28761 java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.bluetooth.BluetoothAdapter.isEnabled()' on a null object reference

MANIFEST:

<uses-feature android:name="android.hardware.bluetooth_le" android:required="true" />
<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-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

Answer 1

From the code given above this seems to be a bluetooth adapter issue which can happen when you either don't give the application the correct permissions in the manifest shown below or the bluetooth is broken. I have added code below which you should use to take into consideration of faulty bluetooth, also make a utility class which you can call this from.

Note: its the bluetooth adapter null not isEnabled

Permissions:

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

Code:

public static boolean isBluetoothEnabled() {
    final BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    return (bluetoothAdapter != null && bluetoothAdapter.isEnabled());
}