android - クイズで正しい答えを表示するためにアクティビティを一時停止する方法は?

Question

HY、まあ、私は Android クイズを作成しています。ボタンをクリックした後のコードからわかるように、新しい質問が自動的に生成されますが、しばらくそのままにして、正しい場合は緑に、正しい場合は赤にします。それは間違っています..一時停止する方法がわかりません.おそらくsleep()メソッド..ありがとうございます！

public class Glavno extends Activity implements OnClickListener {

int score  = 0;
int counter = 0;
boolean ajme = true;

TextView textView1, textView2, textView3, countdown;
Button btn1, btn2, btn3, btn4;

ArrayList<Question> qsts = new ArrayList<Question>();
List<Integer> generated = new ArrayList<Integer>();

ArrayList<String> allAnswers = new ArrayList<String>();

Random rng = new Random();
Question nextQuestion;

Question qjedan = new Question(
    "Q1",

    "Correct answer - q1",
    "Wrong answer 3 - q1",
    "Wrong answer 3 - q1",
    "Wrong answer 3 - q1"
    );
Question q2 = new Question(
    "Q2",

    "Correct answer - q2",
    "Wrong answer 3 - q2",
    "Wrong answer 3 - q2",
    "Wrong answer 3 - q2"
    );
Question q3 = new Question(
    "Q3",

    "Correct answer - q3",
    "Wrong answer 3 - q3",
    "Wrong answer 3 - q3",
    "Wrong answer 3 - q3"
    );


@Override
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.pitanja);

 new CountDownTimer(20000, 1000) {

     public void onTick(long millisUntilFinished) {
         textView4.setText("Seconds remaining: " + millisUntilFinished / 1000);
     }

     public void onFinish() {
         generateQuestion();
         textView2.setText("VRIJEME!");
         textView2.setTextColor(Color.RED);

     }
      }.start();

qsts.add(qjedan);           
qsts.add(q2);
qsts.add(q3);

textView1 = (TextView) findViewById(R.id.textView1);
textView2 = (TextView) findViewById(R.id.textView2);
textView3 = (TextView) findViewById(R.id.textView3);

textView3.setText("Rezultat: " + score);

    btn1 = (Button) findViewById(R.id.btn1);
    btn2 = (Button) findViewById(R.id.btn2);
    btn3 = (Button) findViewById(R.id.btn3);
    btn4 = (Button) findViewById(R.id.btn4);

    btn1.setOnClickListener(this);
    btn2.setOnClickListener(this);
    btn3.setOnClickListener(this);
    btn4.setOnClickListener(this);

generateQuestion();

}

public void generateQuestion(){

    while(ajme = true){

        int nxt = rng.nextInt(3);

        if (!generated.contains(nxt)){

            generated.add(nxt);

            nextQuestion = qsts.get(nxt);

            textView1.setText(nextQuestion.questionText);

            allAnswers.add(nextQuestion.correctAnswerText);
            allAnswers.add(nextQuestion.wrongAnswer1);
            allAnswers.add(nextQuestion.wrongAnswer2);
            allAnswers.add(nextQuestion.wrongAnswer3);

            Collections.shuffle(allAnswers);

            btn1.setText(allAnswers.get(0));
            btn2.setText(allAnswers.get(1));
            btn3.setText(allAnswers.get(2));
            btn4.setText(allAnswers.get(3));

            break;
        }
    }
}


@Override
public void onClick(View v) {
    Button b = (Button)v;
    String buttonText = b.getText().toString();

    if (counter == 3) {

        Intent theIntent = new Intent(this, Score.class);
        theIntent.putExtra("somename", score);  
        startActivity(theIntent);

        finish();   // Added this method call
    }

    else if(buttonText.equals(nextQuestion.correctAnswerText)) { 

        counter++;

        AdView ad = (AdView) findViewById(R.id.ads);
        ad.loadAd(new AdRequest());

        textView2.setText("TOČNO!");
        textView2.setTextColor(Color.GREEN);
        textView3.setText("Rezultat: " + (score += 10));

        allAnswers.clear();
        generateQuestion();

        return;
    } 

    else{

        counter++;

        AdView ad = (AdView) findViewById(R.id.ads);
        ad.loadAd(new AdRequest());

        textView2.setText("NETOČNO!");
        textView2.setTextColor(Color.RED);
        textView3.setText("Rezultat: " + (score -= 5));

        allAnswers.clear();
        generateQuestion();

        return; 
    }

}