临时更改按钮的颜色

Question

I programmed a quiz, now I want that every time the correct answer/button( mButtonChoice ) is pressed the background of the button will be colored green, later it will be set as default.

So the correct buttons should be "colored" green and then later as before. How do I can manage to do that?

QuizActicity (Here are the questions and the choices):-

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

    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();
        }
    });

    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!");
            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);

    List<Button> choices = new ArrayList<>();
    choices.add(mButtonChoice1);
    choices.add(mButtonChoice2);
    choices.add(mButtonChoice3);

    updateQuestion();

    for (final Button choice : choices) {
        choice.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (choice.getText().equals(mAnswer)) {

                    updateScore();
                    updateQuestion();

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

}

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);
}
  }

Answer 1

As a Java developer you should get used to use the online documentation of the components you use.

When you look at the API description of Androids Button class ( https://developer.android.com/reference/android/widget/Button.html ) you might find that it inherits the method setBackgroundColor(int color) from Androids View class ( https://developer.android.com/reference/android/view/View.html#setBackgroundColor(int) )

Then you only need to call that method at the two correct places in your program.

Answer 2

Setting the "background color" for a Button is a little bit tricky. By default, every Button has a background managed by the Android system that includes things like rounded corners, colors only within a certain area, etc. If you simply call setBackgroundColor() , you will lose all of that sophisticated behavior and be left with a flat rectangle.

I assume you're extending from AppCompatActivity here. If not, this answer won't work.

To change a Button 's background color while still keeping the rounded shape and the ripple effect, use ViewCompat.setBackgroundTintList() as follows:

    Button dialogButton = (Button) findViewById(R.id.dialogbtn);
    int color = ContextCompat.getColor(this, R.color.yourColorResourceHere);
    ColorStateList tintList = ColorStateList.valueOf(color);
    ViewCompat.setBackgroundTintList(dialogButton, tintList);