填写ListView Android

Question

首先...... HappyNew Year !!!!我开始学习Android编程，实际上我正在尝试开发一些代码。主要的想法是搜索配对蓝牙设备，并列出所有BT设备附近...稍后我会尝试连接两台设备但不时：P

我的问题应该很简单，因为我用配对的方法填充我的ListView但是使用这段代码我无法填写我发现的那个...但我不知道我做错了什么导致Toast。 MakeText显示这个BT设备但不在ListView ....任何人都可以帮助我???非常感谢

//显示ANDROID VERSION         Context context = getApplicationContext（）;

    //Setting up for JELLY_BEAN_MR1 and above
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.JELLY_BEAN_MR2) {

        BluetoothManager bluetoothManager = (BluetoothManager)context.getSystemService(Context.BLUETOOTH_SERVICE);

        if (bluetoothManager != null)
        {
             mBluetoothAdapter = bluetoothManager .getAdapter();
        }
    } else {

        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    }

    //Enable
    if (!mBluetoothAdapter.isEnabled()) {
        Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
    }
    //Discover my BT
    Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
    discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
    startActivity(discoverableIntent);

    //Paired Devices
    pairedDevices = mBluetoothAdapter.getBondedDevices();
    final ArrayList<String> listBT = new ArrayList<String>();
    ListView lv  =(ListView)findViewById(R.id.listDevicesFound);
    for(BluetoothDevice bt : pairedDevices)
        listBT.add(bt.getName());

    //Starting Search
    final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if(BluetoothDevice.ACTION_FOUND.equals(action)){
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                listBT.add(device.getName()); //Something happens but not adding to ListView
                Toast.makeText(getApplicationContext(), device.getName(),
                        Toast.LENGTH_SHORT).show();
            }
        }
    };

    registerReceiver(mReceiver, new IntentFilter(BluetoothDevice.ACTION_FOUND));
    mBluetoothAdapter.startDiscovery();

    //Show ListView
    lv.setAdapter(new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1 , listBT));

Answer 1

为您的适配器创建一个类变量（在您的类中上面）：

private ArrayAdapter<String> mDeviceListAdapter;

克隆特适配器并将其设置为列表：

//Show ListView
    mDeviceListAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1 , listBT);
    lv.setAdapter(mDeviceListAdapter);

当您有新项目时更新适配器数据：

 @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if(BluetoothDevice.ACTION_FOUND.equals(action)){
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                listBT.add(device.getName()); 
                if(mDeviceListAdapter!=null){
                    mDeviceListAdapter.add(device.getName());
                    mDeviceListAdapter.notifyDataSetChanged();
                }
                Toast.makeText(getApplicationContext(), device.getName(),
                        Toast.LENGTH_SHORT).show();
            }
        }