Question

我正在编写一个Android测验应用程序，现在每次用户回答错误时，会出现冻结计时器，用户必须等到他能够再次回答，我的问题如下：

每次用户回答错误并且计时器显示时，他可以通过按返回主菜单的按钮逃跑，然后按问题按钮重新启动整个事情。

我需要帮助onSaveInstanceState和onRestoreInstanceState功能。

代码是：

public class Questionsctivity extends Activity {

    List<Question> quesList;
    int score = 0;
    int qid = 0;
    Question currentQ;
    TextView txtQuestion,clockView;
    RadioButton rda, rdb, rdc;
    Button butNext;
    private GoogleApiClient client;

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

        setContentView(R.layout.activity_questionsctivity);

        DbHelper db = new DbHelper(this);
        quesList = db.getAllQuestions();
        currentQ = quesList.get(qid);
        clockView = (TextView) findViewById(R.id.textView222);
        txtQuestion = (TextView) findViewById(R.id.textView1);
        rda = (RadioButton) findViewById(R.id.radio0);
        rdb = (RadioButton) findViewById(R.id.radio1);
        rdc = (RadioButton) findViewById(R.id.radio2);

        butNext = (Button) findViewById(R.id.next);

        setQuestionView();

        butNext.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                RadioGroup grp = (RadioGroup) findViewById(R.id.radioGroup1);
                RadioButton answer = (RadioButton) findViewById(grp.getCheckedRadioButtonId());
                Log.d("yourans", currentQ.getANSWER() + " " + answer.getText());
                if (currentQ.getANSWER().equals(answer.getText())) {//bad equal to
                    score++;
                    Log.d("Good Answer", "Your Score" + score);
                } else {
                    Log.d("bad Answer", "Your Score" + score);

                    new CountDownTimer(30000, 1000) {

                        public void onTick(long millisUntilFinished) {
                            clockView.setText("Wrong Answer +" +
                                    "seconds remaining: " + millisUntilFinished / 1000);
                            butNext.setEnabled(false);
                            txtQuestion.setEnabled(false);
                            rda.setEnabled(false);
                            rdb.setEnabled(false);
                            rdc.setEnabled(false);

                        }

                        public void onFinish() {
                            clockView.setText("Continue Answering!");
                            butNext.setEnabled(true);
                            txtQuestion.setEnabled(true);
                            rda.setEnabled(true);
                            rdb.setEnabled(true);
                            rdc.setEnabled(true);
                        }

                    }.start();
                }
                if (qid < 7) {
                    currentQ = quesList.get(qid);
                    setQuestionView();
                } else {
                    Intent intent = new Intent(Questionsctivity.this, ResultActivity.class);
                    Bundle b = new Bundle();
                    b.putInt("score", score); //Your score
                    intent.putExtras(b); //Put your score to your next Intent
                    startActivity(intent);
                    finish();
                }
            }
        });
        client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
    }




    private void setQuestionView() {
        txtQuestion.setText(currentQ.getQUESTION());
        rda.setText(currentQ.getOPTA());
        rdb.setText(currentQ.getOPTB());
        rdc.setText(currentQ.getOPTC());
        qid++;
    }

    @Override
    public void onStart() {
        super.onStart();

        client.connect();
        Action viewAction = Action.newAction(
                Action.TYPE_VIEW, // TODO: choose an action type.
                "Questionsctivity Page", // TODO: Define a title for the content shown.
                // TODO: If you have web page content that matches this app activity's content,
                // make sure this auto-generated web page URL is correct.
                // Otherwise, set the URL to null.
                Uri.parse("http://host/path"),
                // TODO: Make sure this auto-generated app deep link URI is correct.
                Uri.parse("android-app://com.example.ourapp.myapplication/http/host/path")
        );
        AppIndex.AppIndexApi.start(client, viewAction);
    }

    @Override
    public void onStop() {
        super.onStop();


        Action viewAction = Action.newAction(
                Action.TYPE_VIEW, // TODO: choose an action type.
                "Questionsctivity Page", // TODO: Define a title for the content shown.
                // TODO: If you have web page content that matches this app activity's content,
                // make sure this auto-generated web page URL is correct.
                // Otherwise, set the URL to null.
                Uri.parse("http://host/path"),
                // TODO: Make sure this auto-generated app deep link URI is correct.
                Uri.parse("android-app://com.example.ourapp.myapplication/http/host/path")
        );
        AppIndex.AppIndexApi.end(client, viewAction);
        client.disconnect();
    }
}

Answer 1

您只需使用手动创建的onSaveInstanceState手动调用Bundle。

@Override
public void onBackPressed() {
    Bundle bundle = new Bundle();
    bundle.putString(key, value);
    onSaveInstanceState(bundle);
    super.onBackPressed(); //Check if you still want to go back
}

Answer 2

使用以下内容禁用后退按钮或根据您的要求使用。

  @Override
    public void onBackPressed() {
        super.onBackPressed();
    // use your own custom method or you can remove super.onBackPressed(); to disable back button.
    }

Answer 3

您必须使用onPause()方法来保存Activity的状态，因为只有在系统要销毁Activity时才会调用onSaveInstanceState()（如果内存需要是释放）。如果用户按下后退（或主页）按钮以关闭当前活动，则不会调用onSaveInstanceState()。

例如，您可以将当前状态保留在共享首选项或本地数据库中。

然后，您可以使用onResume()方法恢复已保存的状态。

按下后退按钮时如何保存状态

3 个答案: