我已经设置了一个复选框,现在如果取消选中,媒体播放器应该立即取消静音,当检查立即静音时,现在问题是当我选中/取消选中复选框时,声音不会立即静音但是最近我重新开始活动… 我怎么解决这个问题？

该计划的主要代码：

public class QuizActivity extends AppCompatActivity {

private ActionBarDrawerToggle mToggle;

private QuestionLibrary mQuestionLibrary = new QuestionLibrary();

private TextView mScoreView;

private TextView mQuestionView;

private Button mButtonChoice1;

private Button mButtonChoice2;

private Button mButtonChoice3;

private String mAnswer;

private int mScore = 0;

private int mQuestionNumber = 0;

Dialog dialog;

Dialog dialog2;

TextView closeButton;

TextView closeButton2;

CheckBox checkBoxmp;

private MediaPlayer mp, mp2;

SharedPreferences mypref;

SharedPreferences.Editor editor;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_quiz);

//Dialog 1

createDialog();

Button dialogButton = (Button) findViewById(R.id.dialogbtn);

dialogButton.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

dialog.show();

}

});

closeButton.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

dialog.dismiss();

}

});

//end Dialog 1

//Dialog 2

createDialog2();

Button dialogButton2 = (Button) findViewById(R.id.dialogbtn2);

dialogButton2.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

dialog2.show();

}

});

closeButton2.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

dialog2.dismiss();

}

});

//end Dialog 2

SharedPreferences mypref = getPreferences(MODE_PRIVATE);

final SharedPreferences.Editor editor = mypref.edit();

checkBoxmp.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

@Override

public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

editor.putBoolean("playSounds", !isChecked);

editor.commit();

if (null != mp && null != mp2) {

if (!isChecked) {

mp.setVolume(1, 1);

mp2.setVolume(1, 1);

} else {

mp.setVolume(0, 0);

mp2.setVolume(0, 0);

}

}

}

});

final boolean playSounds = mypref.getBoolean("playSounds", false);

checkBoxmp.setChecked(!playSounds);

TextView shareTextView = (TextView) findViewById(R.id.share);

shareTextView.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

Intent myIntent = new Intent(Intent.ACTION_SEND);

myIntent.setType("text/plain");

myIntent.putExtra(Intent.EXTRA_SUBJECT, "Hello!");

myIntent.putExtra(Intent.EXTRA_TEXT, "My highscore in Quizzi is very high! I bet you can't beat me except you are cleverer than me. Download the app now! https://play.google.com/store/apps/details?id=amapps.impossiblequiz");

startActivity(Intent.createChooser(myIntent, "Share with:"));

}

});

mQuestionLibrary.shuffle();

setSupportActionBar((Toolbar) findViewById(R.id.nav_action));

DrawerLayout mDrawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);

mToggle = new ActionBarDrawerToggle(this, mDrawerLayout, R.string.open, R.string.close);

mDrawerLayout.addDrawerListener(mToggle);

mToggle.syncState();

getSupportActionBar().setDisplayHomeAsUpEnabled(true); // Able to see the Navigation Burger "Button"

((NavigationView) findViewById(R.id.nv1)).setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {

@Override

public boolean onNavigationItemSelected(MenuItem menuItem) {

switch (menuItem.getItemId()) {

case R.id.nav_stats:

startActivity(new Intent(QuizActivity.this, Menu2.class));

break;

case R.id.nav_about:

startActivity(new Intent(QuizActivity.this, Menu3.class));

break;

}

return true;

}

});

mScoreView = (TextView) findViewById(R.id.score_score);

mQuestionView = (TextView) findViewById(R.id.question);

mButtonChoice1 = (Button) findViewById(R.id.choice1);

mButtonChoice2 = (Button) findViewById(R.id.choice2);

mButtonChoice3 = (Button) findViewById(R.id.choice3);

final List choices = new ArrayList<>();

choices.add(mButtonChoice1);

choices.add(mButtonChoice2);

choices.add(mButtonChoice3);

updateQuestion();

//Code of the mediaplayer begins:

for (final Button choice : choices) {

choice.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View view) {

if (choice.getText().equals(mAnswer)) {

try {

mp = new MediaPlayer();

if (playSounds) {

mp.setVolume(1, 1);

} else {

mp.setVolume(0, 0);

}

AssetFileDescriptor afd;

afd = getAssets().openFd("sample.mp3");

mp.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());

mp.prepare();

} catch (IllegalStateException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

mp.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {

@Override

public void onCompletion(MediaPlayer mp) {

mp.release();

}

});

mp.start();

updateScore();

updateQuestion();

Toast.makeText(QuizActivity.this, "Correct", Toast.LENGTH_SHORT).show();

} else {

try {

mp2 = new MediaPlayer();

if (playSounds) {

mp2.setVolume(1, 1);

} else {

mp2.setVolume(0, 0);

}

AssetFileDescriptor afd;

afd = getAssets().openFd("wrong.mp3");

mp2.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());

mp2.prepare();

} catch (IllegalStateException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

mp2.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {

@Override

public void onCompletion(MediaPlayer mp) {

mp.release();

}

});

mp2.start();

Toast.makeText(QuizActivity.this, "Wrong... Try again!", Toast.LENGTH_SHORT).show();

Intent intent = new Intent(QuizActivity.this, Menu2.class);

intent.putExtra("score", mScore); // pass score to Menu2

startActivity(intent);

}

}

});

}

}

//End mediaplayer main code

private void updateQuestion() {

if (mQuestionNumber < mQuestionLibrary.getLength()) {

mQuestionView.setText(mQuestionLibrary.getQuestion(mQuestionNumber));

mButtonChoice1.setText(mQuestionLibrary.getChoice1(mQuestionNumber));

mButtonChoice2.setText(mQuestionLibrary.getChoice2(mQuestionNumber));

mButtonChoice3.setText(mQuestionLibrary.getChoice3(mQuestionNumber));

mAnswer = mQuestionLibrary.getCorrectAnswer(mQuestionNumber++);

} else {

Toast.makeText(QuizActivity.this, "Last Question! You are very intelligent!", Toast.LENGTH_SHORT).show();

Intent intent = new Intent(QuizActivity.this, Menu2.class);

intent.putExtra("score", mScore);

startActivity(intent);

}

}

private void updateScore() {

mScoreView.setText(String.valueOf(++mScore));

SharedPreferences mypref = getPreferences(MODE_PRIVATE);

int highScore = mypref.getInt("highScore", 0);

if (mScore > highScore) {

SharedPreferences.Editor editor = mypref.edit();

editor.putInt("highScore", mScore);

editor.apply();

}

}

@Override

public boolean onOptionsItemSelected(MenuItem item) {

return mToggle.onOptionsItemSelected(item) || super.onOptionsItemSelected(item);

}

private void createDialog() {

dialog = new Dialog(this);

dialog.setTitle("Tutorial");

dialog.setContentView(R.layout.popup_menu1_1);

closeButton = (TextView) dialog.findViewById(R.id.closeTXT);

}

private void createDialog2() {

dialog2 = new Dialog(this);

dialog2.setTitle("Settings");

dialog2.setContentView(R.layout.popup_menu1_2);

closeButton2 = (TextView) dialog2.findViewById(R.id.closeTXT2);

checkBoxmp = (CheckBox) dialog2.findViewById(R.id.ckeckBox);

}

}