java - 找到重复的蓝牙设备。我在这儿蘸两次吗？也能够更新recyclerview

我正在尝试构建一个扫描蓝牙设备的android应用程序并将其添加到recyclerview。当我尝试清除阵列列表并向适配器中添加新数据时，我得到一个空的阵列列表。当我不清除列表时，我最终得到一个包含每个设备两次的列表，如下所示:logcat中的[**:71:9F:B6:59:**, **:71:9F:B6:59:**]。我也认为我的notifydatasetchanged调用在这里做错了，因为在我的recyclerview中什么都没有显示。我确定这很简单，我很想念，但我看不到它。我正在发布主要 Activity 的代码以及我的recyclerview.adapter代码，希望有人可以向我指出问题。提前致谢。这是我的主要 Activity :

public class ToofActivity extends AppCompatActivity implements CompoundButton.OnCheckedChangeListener {

private static final String TAG = "ToofActivity";
private static final int REQUEST_COARSE_LOCATION = 222;

private static BluetoothAdapter btAdapter;

private TextView mStatusLabel;
private Switch mStatusSwitch;
private ProgressBar mProgressBar;
private RecyclerView mDeviceRecylcer;
private static ArrayList<BluetoothDevice> mDevices = new ArrayList<>();
private DeviceAdapter mAdapter;

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

    checkLocationPermission();

    btAdapter = BluetoothAdapter.getDefaultAdapter();

    mStatusLabel = (TextView) findViewById(R.id.status_view);
    mStatusSwitch = (Switch) findViewById(R.id.status_switch);
    mStatusSwitch.setChecked(btAdapter.isEnabled());
    mStatusSwitch.setOnCheckedChangeListener(this);
    mProgressBar = (ProgressBar) findViewById(R.id.search_progress_bar);
    mDeviceRecylcer = (RecyclerView) findViewById(R.id.device_recycler);

    mDeviceRecylcer.setLayoutManager(new LinearLayoutManager(this));
    mAdapter = new DeviceAdapter(mDevices, getApplicationContext());
    mDeviceRecylcer.setAdapter(mAdapter);

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.options_menu, menu);
    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.searchOption:
            DiscoveryTask discovery = new DiscoveryTask(btAdapter, this, mDevices, mProgressBar);
            discovery.setOnCompleteListener(new DiscoveryTask.OnCompletedListener() {
                @Override
                public void onComplete() {
                    Log.d(TAG, "devices found : " + mDevices.toString());
                    mAdapter.updateItems(mDevices);
                }
            });
            discovery.execute((Void) null);
            break;
    }

    return true;
}

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    if (isChecked) {
        btAdapter.enable();
        mStatusLabel.setText("Active");
    } else {
        btAdapter.disable();
        mStatusLabel.setText("Inactive");
    }
}

public static void setDeviceList(ArrayList<BluetoothDevice> deviceList) {
    mDevices = deviceList;
}

protected void checkLocationPermission() {
    if (this.checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION)
            != PackageManager.PERMISSION_GRANTED) {

        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
                REQUEST_COARSE_LOCATION);
    }
}

@Override
public void onRequestPermissionsResult(int requestCode,
                                       String permissions[], int[] grantResults) {
    switch (requestCode) {
        case REQUEST_COARSE_LOCATION: {
            if (grantResults.length <= 0
                    || grantResults[0] != PackageManager.PERMISSION_GRANTED) {
                checkLocationPermission();
                break;
            }
        }
    }
}
}

还有我的适配器类，它是用kotlin而不是Java编写的:

class DeviceAdapter(val mDevices: ArrayList<BluetoothDevice>, val mContext : Context) : RecyclerView.Adapter<DeviceAdapter.DeviceHolder>(){

fun updateItems(list: ArrayList<BluetoothDevice>){
    //mDevices.clear()
    mDevices.addAll(list)
    Log.d(TAG, "updating items : $mDevices")
    notifyDataSetChanged()
}

override fun onBindViewHolder(holder: DeviceHolder, position: Int) {
    holder.bindItems(mDevices.get(position))
}

override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): DeviceHolder?{ //return is not to be NULL!
    val v = LayoutInflater.from(mContext).inflate(R.layout.device_item, parent, false)
    return DeviceHolder(v)
}

override fun getItemCount(): Int {
    return mDevices.size
}

inner class DeviceHolder(itemView: View) : RecyclerView.ViewHolder(itemView){
    val nameView = itemView.findViewById(R.id.nameView) as TextView
    val addrView = itemView.findViewById(R.id.addressView) as TextView

    fun bindItems(btDevice: BluetoothDevice){
        nameView.text = btDevice.name
        addrView.text = btDevice.address
    }
}

companion object {
    val TAG = "DeviceAdapter"
}

}

最佳答案

问题在于DeviceAdapter.mDevices与ToofActivity.mDevices是同一对象。因此，当您清除它时，对于mDevices.addAll(mDevices)来说，两个元素都变为空。

从mDevices的构造函数参数中删除DeviceAdapter。
在ArrayList中为其创建一个新的DeviceAdapter。