Android从其他线程获取EditText内容

Question

In my problem, I have my MainActivity , with a TextView and EditText , and a method, which should send out messages to the TextView and receive the content of an EditText . The problem is receiving text from the EditText, and making this method wait for the user input

I'll try to post my cropped code so you will gain some knowledge about what I am trying to achieve.

public class MainActivity extends Activity {

public class MonitorObject{
}
final MonitorObject mSync = new MonitorObject();
private TextView mConsoleOut;
private EditText mInputLine;
public String inputString;
public synchronized String getInputString(String value){this.inputString = value; return inputString;}

IOHandler IOhandler;

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

    mConsoleOut = (TextView) findViewById(R.id.consoleOut);
    mInputLine = (EditText) findViewById(R.id.actionInField);


    EditText editText = (EditText) findViewById(R.id.actionInField);
    editText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
            synchronized (mSync){
                mSync.notify();
            }
            return true;
        }
    });
    GameCycle gameCycle = new GameCycle();
    Thread gameloop = new Thread(gameCycle);
    gameloop.start();
}

public class GameCycle implements Runnable{
    public void run(){
        game();
    }
}

public void game(){
findViewById(R.id.actionInField);
    Integer time=0;
    PlayerClass p1 = new PlayerClass(1,4);
    TileClass tile = new TileClass.Forest();
    Integer gamestate=0;


    while(gamestate==0){
        time++;
        tile.initialize_tilesettings(time, p1);
        tile.passed=true;
        List actionResponse=new ArrayList(Arrays.asList("repeat", "type", "returnval"));

        while(gamestate==0 && !actionResponse.get(1).equals("tileChange")){

            actionResponse=Arrays.asList("repeat", "type", "returnval");
            Boolean tileActions = true;

            while(!actionResponse.get(0).equals("continue")){
                //actions to be repeated

                String exe=null;

                tileActions=true;

                List<String> params = new ArrayList<>();

                <<<<<print>>>>>("\nWhat will you do?");

                synchronized (mSync){
                    try {
                        mSync.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }

                <<<<<getinput>>>>>String inp=returnInputString();
                String[] splitIn=inp.split(" ");


                for(String text:splitIn){
                    params.add(text.toLowerCase());
                }

                for(ActionClass action:p1.getActions()){
                    if(action.method.contains(params.get(0))){
                        exe=action.method;
                    }
                }

                if(exe==null){
                    <<<<<print>>>>>("Not a valid action");

                    actionResponse=Arrays.asList("repeat","","");
                }
                else{
                    try{
                        actionResponse=p1.excecFunctionByTag(exe, Arrays.asList(p1, tile, params));
                        if(actionResponse==null){
                            throw new RuntimeException();
                        }
                    }
                    catch (Exception e){
                        for(ActionClass action:p1.getActions()){
                            if(exe.equals(action.method)){
                                String actionEnt=action.actionEntry;
                                <<<<<print>>>>>("\nInvalid parameters, try: "+actionEnt);
                                actionResponse=Arrays.asList("repeat","","");
                            }
                        }
                    }
                    return;
                }


            }
        }
        if(gamestate==1){
            <<<<<print>>>>>('You died! Game over!\n\n<-<-< New Game >->->\n\n')
            game();
        }
        else if(gamestate==2){
            <<<<<print>>>>>("You have defeated the boss! Behind the fallen enemy you can see a path. You follow it and find a small village. You are safe!\n\n<-<-< New Game >->->\n\n")
            game();
        }
    }
}

I have marked the required input/output methods with <<<<< >>>>> .

Have mercy with my java skills, since this is my first large project in java and the whole structure is converted from python.

Again, all help is greatly appreciated.

Answer 1

The problem is simple that normally threads don't notify back to the ui or the main thread. And to solve this issue android has AsyncTask. You can use AsyncTask as:

1. Initiate your TextView and EditText in onPreExecute() method.
2. Send or call your methods to send what so ever text you want in doInBackground() method.
3. You will then get the result in onPostExecute() method. Here you can setText() to your EditText.

Note: AsyncTask is a thread that contact backs to the main ui thread, for which it has this onPostExecute() method.

For better understanding of AsyncTask check this link: http://www.androidhive.info/2012/01/android-json-parsing-tutorial/

Answer 2

Okay, so as far I understand from your question, You want to get some text from UI (which is handled by UIThread), process it on a worker thread and post the resultant text in a TextView again in UI (UIThread).

This is how I would do it in MainActivity:

 final String line = editText.getText().toString();
// This Handler is associated with our UI thread as it is initialized here and will handle communication with Worker thread.
        uiHandler = new Handler();
        worker = new Worker();
        worker.start();
        worker.doWork(new Runnable() {
            @Override
            public void run() {
                // processing 'line' here and posting back
                 // result to your textView.
               // UI thread's handler is used to communicate our results back.
                 uiHandler.post(new Runnable() {
                            @Override
                            public void run() {
                                textView.setText(result);
                            }
                        }); 
            }
    });

and finally, the Worker thread class :

/* A worker thread for offloading heavy work so as to keep UI thread responsive
* and smooth */

public class Worker extends HandlerThread {
    public final String NAME = "Worker";
    private Handler handler;

    public Worker() {
        super("Worker", HandlerThread.NORM_PRIORITY);
    }

    public void prepareHandler() {
        handler = new Handler(getLooper());
    }

    // do some work in background
    public void doWork(Runnable someWork) {
        prepareHandler();
        handler.post(someWork);
    }
}

I hope this helps someone. Happy coding!