如何将数据从 Broadcast Receiver 传递到 Recycler view Item

Question

我是 Android 的新手，我添加了 Modbus 客户端库以从其在前台成功工作的 modbus 设备接收数据，使用发送到 UI 的广播接收器，将数据传递到图像下方的 recyclerview 项目（更改数据 Text1、Text2、Text3、Text4、Text5 )

下面的代码

前台服务.java

public class ForegroundService extends Service {
    public static final String CHANNEL_ID = "ForegroundServiceChannel";
    public static final String NOTIFICATION_CHANNEL_ID = "10001" ;
    private final static String default_notification_channel_id = "default" ;
    MyServiceThread myServiceThread;
    final static String KEY_INT_FROM_SERVICE = "KEY_INT_FROM_SERVICE";
    final static String KEY_INT_FROM_SERVICE2 = "KEY_INT_FROM_SERVICE2";
    final static String KEY_INT_FROM_SERVICE3 = "KEY_INT_FROM_SERVICE3";
    final static String KEY_INT_FROM_SERVICE4 = "KEY_INT_FROM_SERVICE4";
    final static String KEY_INT_FROM_SERVICE5 = "KEY_INT_FROM_SERVICE5";
    final static String ACTION_UPDATE_CNT = "UPDATE_CNT";
    int cnt;
    String ret = "";
    int val1 = 0;
    int val2 = 0;
    int val3 = 0;
    int val4 = 0;
    int val5 = 0;
    @Override
    public void onCreate() {
        ModbusReq.getInstance().setParam(new ModbusParam()
                .setHost("10.0.2.2")
                .setPort(502)
                .setEncapsulated(false)
                .setKeepAlive(true)
                .setTimeout(2000)
                .setRetries(0))
                .init(new OnRequestBack<String>() {
                    @Override
                    public void onSuccess(String s) {
                        Log.d("TAG", "onSuccess " + s);
                    }

                    @Override
                    public void onFailed(String msg) {
                        Log.d("TAG", "onSuccess " + msg);
                    }
                });
        super.onCreate();
    }
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        String input = intent.getStringExtra("inputExtra");
        createNotificationChannel();
        Intent notificationIntent = new Intent(this, MainActivity.class);
        PendingIntent pendingIntent = PendingIntent.getActivity(this,
                0, notificationIntent, 0);
        Notification notification = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setContentTitle("Foreground Service")
                .setContentText(input)
                .setSmallIcon(R.drawable.notification)
                .setContentIntent(pendingIntent)
                .build();
        startForeground(1, notification);
        myServiceThread = new MyServiceThread();
        myServiceThread.start();
        return START_NOT_STICKY;

    }
    @Override
    public void onDestroy() {
        myServiceThread.setRunning(false);
        super.onDestroy();
    }
    private class PlcReader extends AsyncTask<String,Void,String> {

        @Override
        protected String doInBackground(String... strings) {
            try{
                ModbusReq.getInstance().readHoldingRegisters(new OnRequestBack<short[]>() {
                    @Override
                    public void onSuccess(short[] data) {
                        val1 = data[0];
                         val2 = data[1];
                         val3 = data[2];
                         val4 = data[3];
                         val5 = data[4];
                    }

                    @Override
                    public void onFailed(String msg) {
                        Log.e("TAG", "readHoldingRegisters onFailed " + msg);
                    }
                }, 1, 0, 8);
            }
            catch (Exception e)
            {
                ret= "Exe"+e.toString();
                Thread.interrupted();
            }
            return "Executed";
        }

        @Override
        protected void onPostExecute(String s) {
              Intent intent = new Intent();
              intent.setAction(ACTION_UPDATE_CNT);
              intent.putExtra(KEY_INT_FROM_SERVICE, val1);
              intent.putExtra(KEY_INT_FROM_SERVICE2, val2);
              intent.putExtra(KEY_INT_FROM_SERVICE3, val3);
              intent.putExtra(KEY_INT_FROM_SERVICE4, val4);
              intent.putExtra(KEY_INT_FROM_SERVICE5, val5);
              sendBroadcast(intent);
            
                    }
                } , delayInMilliseconds) ;
            }
        }
    }
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
    private void createNotificationChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel serviceChannel = new NotificationChannel(
                    CHANNEL_ID,
                    "Foreground Service Channel",
                    NotificationManager.IMPORTANCE_DEFAULT
            );
            NotificationManager manager = getSystemService(NotificationManager.class);
            manager.createNotificationChannel(serviceChannel);
        }
    }
    private class MyServiceThread extends Thread{
        private boolean running;
        public void setRunning(boolean running){
            this.running = running;
        }
        @Override
        public void run() {
            cnt = 0;
            running = true;
            while (running){
                try {
                    Thread.sleep(1000);
                    cnt++;
                    new PlcReader().execute("");
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

TextAdapter.java

public class TextAdapter extends RecyclerView.Adapter<TextAdapter.ItemViewHolder> {
    private Context context;
    private String[] Values = {"Text 1", "Text 2","Text 3","Text 4","Text 5"};
    private String[] City = {"Dubai", "Italy","India","USA","UK"};
    public TextAdapter(Context context) {
        this.context = context;
    }
    @NonNull
    @Override
    public ItemViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.item_layout,parent,false);
        return new ItemViewHolder(view);
    }
    @Override
    public void onBindViewHolder(@NonNull ItemViewHolder holder, int position) {
        holder.txtView.setText(Values[position]);
        holder.txtView2.setText(City[position]);
    }
    @Override
    public int getItemCount() {
        return Values.length;
    }
    class ItemViewHolder extends RecyclerView.ViewHolder{
        private TextView txtView;
        private TextView txtView2;
        public ItemViewHolder(@NonNull View itemView) {
            super(itemView);
            txtView = itemView.findViewById(R.id.txtView);
            txtView2 = itemView.findViewById(R.id.cities);
        }
    }
}

RecycerActivity.java

public class RecyclerActivity extends AppCompatActivity {
    private RecyclerView recyclerView;
    MyMainReceiver myMainReceiver;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list);
        recyclerView = findViewById(R.id.recyclerView);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setHasFixedSize(true);
        TextAdapter textAdapter = new TextAdapter(getApplicationContext());
        recyclerView.setAdapter(textAdapter);
    }
    @Override
    protected void onStart() {
        myMainReceiver = new MyMainReceiver();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(ForegroundService.ACTION_UPDATE_CNT);
        registerReceiver(myMainReceiver, intentFilter);
        super.onStart();
    }
    private class MyMainReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if(action.equals(ForegroundService.ACTION_UPDATE_CNT)){
                int int_from_service = intent.getIntExtra(ForegroundService.KEY_INT_FROM_SERVICE, 0);
                int int_from_service2 = intent.getIntExtra(ForegroundService.KEY_INT_FROM_SERVICE2, 0);
                int int_from_service3 = intent.getIntExtra(ForegroundService.KEY_INT_FROM_SERVICE3, 0);
                int int_from_service4 = intent.getIntExtra(ForegroundService.KEY_INT_FROM_SERVICE4, 0);
                int int_from_service5 = intent.getIntExtra(ForegroundService.KEY_INT_FROM_SERVICE5, 0);
                Toast.makeText(getApplicationContext(),String.valueOf(int_from_service3), Toast.LENGTH_LONG).show();
            }
        }
    }
}

在前台服务中每 1 秒运行一次线程，每秒从前台服务到 Recycler view item 的数据帮助我解决了这个问题

Answer 1

您的回收器适配器中应该有一个更新方法，当您收到新数据时，您可以从您的活动中调用该更新方法并显示新数据。