如何从另一个活动中终止/结束一个活动？

Question

我有一个包含36个按钮（6X6）的活动，就像国际象棋棋盘一样，当我点击其中一个按钮时，我会调用另一个类来弹出一个问题。以下是示例（针对第一个按钮）：

public void onClick(View v) {
        switch(v.getId()){

        case R.id.ib1:

            Intent i = new Intent(Cigle.this, Pitanja_Cigle.class);
            startActivityForResult(i, B1);
            break;

然后，问题出现了（Pitanja_Cigle.class）。

120秒后时间到了，我有另一个弹出类（Popup_opis.class），告诉用户时间到了和一些其他信息，这与此无关。

问题是，在游戏的最后几秒钟，当我点击36个按钮中的一个并弹出一个问题时，时间已经到了，但我没有及时回答问题，Popup_opis.class会弹出，当我点击它中的“确定”以关闭它时，我可以看到上一个问题仍然是打开的。如何在时间结束时立即杀死/完成该问题活动？

这是我的Popup_opis.class:

public class Popup_opis extends Activity implements OnClickListener{

    TextView tvOpis,tvNaslov,tvBrojPoena, tvResenje;
    String primljenOpis, naslov, resenje;
    int brojPoenaPrimljeno;
    Button OK;



    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

        setContentView(R.layout.popup_opis);

        Bundle extras = getIntent().getExtras(); 
        if(extras !=null) {
           primljenOpis = extras.getString("poslatOpis");
           brojPoenaPrimljeno = getIntent().getIntExtra("brojPoenaPrimljeno", 0);
           naslov = extras.getString("naslov");
           resenje = extras.getString("resenje");
        }

        initVariables();

    }

    private void initVariables() {


        Typeface tv = Typeface.createFromAsset(getAssets(), "ARIALN.TTF");
        OK = (Button) findViewById(R.id.bOK);
        tvOpis = (TextView) findViewById(R.id.tvOpis);
        tvBrojPoena = (TextView) findViewById(R.id.tvBrojPoena);
        tvBrojPoena.setTypeface(tv);
        tvNaslov = (TextView) findViewById(R.id.tvNaslov);
        tvNaslov.setTypeface(tv);
        tvResenje = (TextView) findViewById(R.id.tvResenje);
        tvResenje.setTypeface(tv);
        tvOpis.setTypeface(tv);
        tvOpis.setText(primljenOpis);
        tvBrojPoena.setText("Osvojili ste " + brojPoenaPrimljeno + " poena u ovoj igri.");
        tvNaslov.setText(naslov);
        tvResenje.setText(resenje);



    OK.setOnClickListener(new OnClickListener() {

        public void onClick(View v) {
            finish();
        }
    });
    }



    public void onBackPressed() {
        super.onBackPressed();
        finish();
    }

    public void onClick(View v) {
        // TODO Auto-generated method stub

    }

}

以及我的问题类，Pitanja_cigle.class：

public class Pitanja_Cigle extends Activity{

    public static String tacanOdg;
    int counter = 0;

    Button b1, b2, b3, b4;
    TextView question;
    boolean tacno = true;
    boolean pogresno = false;


LinkedList<Long> mAnsweredQuestions = new LinkedList<Long>();

    private String generateWhereClause(){
        StringBuilder result = new StringBuilder();
        for (Long l : mAnsweredQuestions){
            result.append(" AND _ID <> " + l);
        }
        return result.toString();
    }

    Runnable mLaunchTaskFinish = new Runnable() {
        public void run() {
            finish();
        }
     };

    private class Answer {
        public Answer(String opt, boolean correct) {
            option = opt;
            isCorrect = correct;
        }

        String option;
        boolean isCorrect;
    }
    Handler mHandler = new Handler();

    final OnClickListener clickListener = new OnClickListener() {
        public void onClick(View v) {
            Answer ans = (Answer) v.getTag();
            if (ans.isCorrect) {
                Intent resp = new Intent();
                resp.putExtra("score", tacno);
                setResult(1, resp);
                Intent i = new Intent("rs.androidaplikacije.toplo_hladno.TACANODGOVOR");
                startActivity(i);
                mHandler.postDelayed(mLaunchTaskFinish,1200);
            }
            else{
                Intent resp = new Intent();
                resp.putExtra("score", pogresno);
                setResult(1, resp);
                Intent i = new Intent(getApplicationContext(), PogresanOdgovor.class);
                i.putExtra("tacanOdgovor", tacanOdg);
                startActivity(i);
                mHandler.postDelayed(mLaunchTaskFinish,2200);
            }
        }
     };


    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


        requestWindowFeature(Window.FEATURE_NO_TITLE);   //full screen
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

        setContentView(R.layout.pitanja_cigle);

        InicirajVariable();

        nextQuestion();
    }

    private void nextQuestion() {
        counter++;

        TestAdapter mDbHelper = new TestAdapter(this);
        DataBaseHelper myDbHelper = new DataBaseHelper(this);

        if(!myDbHelper.checkDataBase()){
        mDbHelper.createDatabase();
        }

        try{    //Pokusava da otvori db

            mDbHelper.open();  //baza otvorena

            Cursor c = mDbHelper.getPitanjaCigle(generateWhereClause());

            mAnsweredQuestions.add(c.getLong(0));

            List<Answer> labels = new ArrayList<Answer>();

            labels.add(new Answer(c.getString(2), true));
            labels.add(new Answer(c.getString(3), false));
            labels.add(new Answer(c.getString(4), false));
            labels.add(new Answer(c.getString(5), false));

            tacanOdg = c.getString(2);

            Collections.shuffle(labels);

            question.setText(c.getString(1));

            b1.setText(labels.get(0).option);
            b1.setTag(labels.get(0));
            b1.setOnClickListener(clickListener);

            b2.setText(labels.get(1).option);
            b2.setTag(labels.get(1));
            b2.setOnClickListener(clickListener);

            b3.setText(labels.get(2).option);
            b3.setTag(labels.get(2));
            b3.setOnClickListener(clickListener);

            b4.setText(labels.get(3).option);
            b4.setTag(labels.get(3));
            b4.setOnClickListener(clickListener);

    }

    finally{    // kada zavrsi sa koriscenjem baze podataka, zatvara db
        mDbHelper.close();
    }
    }

    private void InicirajVariable() {
        Typeface pitanje = Typeface.createFromAsset(getAssets(), "myriad.ttf");
        Typeface dugmad = Typeface.createFromAsset(getAssets(), "Bebas.ttf");

        question = (TextView) findViewById(R.id.tvPitanjeCigle);
        b1 = (Button) findViewById(R.id.bOdgCigle1);
        b2 = (Button) findViewById(R.id.bOdgCigle2);
        b3 = (Button) findViewById(R.id.bOdgCigle3);
        b4 = (Button) findViewById(R.id.bOdgCigle4);

        b1.setTypeface(dugmad);
        b2.setTypeface(dugmad);
        b3.setTypeface(dugmad);
        b4.setTypeface(dugmad);
        question.setTypeface(pitanje);

    }
}

堆栈跟踪：

 06-07 14:16:23.631: E/AndroidRuntime(5523): FATAL EXCEPTION: main
    06-07 14:16:23.631: E/AndroidRuntime(5523): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=30, result=0, data=null} to activity {rs.androidaplikacije.toplo_hladno/rs.androidaplikacije.toplo_hladno.Cigle}: java.lang.NullPointerException
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at android.app.ActivityThread.deliverResults(ActivityThread.)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at android.app.ActivityThread.handleSendResult(ActivityThread.)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at android.app.ActivityThread.access$2000(ActivityThread.)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at android.app.ActivityThread$H.handleMessage(ActivityThread.)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at android.os.Handler.dispatchMessage(Handler.java:99)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at android.os.Looper.loop(Looper.)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at android.app.ActivityThread.main(ActivityThread.)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at java.lang.reflect.Method.invokeNative(Native Method)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at java.lang.reflect.Method.invoke(Method.)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at dalvik.system.NativeStart.main(Native Method)
    06-07 14:16:23.631: E/AndroidRuntime(5523): Caused by: java.lang.NullPointerException
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at rs.androidaplikacije.toplo_hladno.Cigle.onActivityResult(Cigle.)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at android.app.Activity.dispatchActivityResult(Activity.)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     at android.app.ActivityThread.deliverResults(ActivityThread.)
    06-07 14:16:23.631: E/AndroidRuntime(5523):     ... 11 more

- marjanbaz

Answer 1

在Pitanja_cigle的onCreate方法中注册广播接收器。

private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action= intent.getStringExtra("action");
        if(action.equals("close")) {
            Pitanja_cigle.this.finish();
        }
    }
};

@Override
public void onCreate(Bundle savedInstanceState) {
    LocalBroadcastManager.getInstance(this).registerReceiver(broadcastReceiver, new IntentFilter("Pitanja_cigle"));
}

每当您想要关闭它时，请执行

public static void closePitanja(Context context) {
    Intent intent = new Intent("Pitanja_cigle");
    intent.putExtra("action", "close");
    LocalBroadcastManager.getInstance(context).sendBroadcast(intent);
}

- Chor Wai Chun

---

我在我的Cigle.class中尝试使用Pitanja_Cigle.closePitanja(getApplicationContext()); 在计时器完成后执行此操作，但是我收到了错误消息“Failure delivering result ResultInfo to activity”。 - marjanbaz

我认为问题在于我启动了Pitanja_cigle类来获取结果。 - marjanbaz

不行，还是同样的错误。在我弹出窗口上按下“确定”按钮后，应用程序崩溃了。 - marjanbaz

你想设置什么作为活动结果？我认为在调用Pitanja_cigle的finish()之前应该先设置一个结果。 - Chor Wai Chun

你正在从弹出框中调用“finish”函数，因为他未能回答问题，“我是对的”吗？所以我认为你应该发送一个错误信号。 - Chor Wai Chun

Answer 2

我的建议是在按下“确定”按钮的同时，在Pitanja_cigle活动上调用finish()函数。

OK.setOnClickListener(new OnClickListener() {

        public void onClick(View v) {
            Pitanja_cigle.this.finish();
            finish();
        }
    });

- verybadalloc

---

我收到了“在范围内无法访问类型Pitanja_cigle的封闭实例”错误。 - marjanbaz