Does onCreate create an instance of the class?

Question

I'm new to Android. Do I understand correctly that if we write ClassName.this, do we refer to an instance of ClassName? If so, what does the QuizActivity.this parameter refer to (last line) in method of onCreate?

public class QuizActivity extends AppCompatActivity {
private Button mTrueButton;
private Button mFalseButton;
private Button mNextButton;
private TextView mQuestionTextView;
private Question[] mQuestionBank= new Question[]{
        new Question(R.string.question_oceans, true),
        new Question(R.string.question_mideast, false),
        new Question(R.string.question_africa, false),
        new Question(R.string.question_americas, true),
        new Question(R.string.question_asia, true),
};
private int mCurrentIndex = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_quiz);
    mQuestionTextView = (TextView) findViewById(R.id.question_text_view);
    int question = mQuestionBank[mCurrentIndex].getTextResId();
    mQuestionTextView.setText(question);
    mTrueButton = (Button) findViewById(R.id.true_button);
    mFalseButton = (Button) findViewById(R.id.false_button);

    mTrueButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Toast.makeText(QuizActivity.this,R.string.correct_toast,Toast.LENGTH_SHORT).show();
        }
    });
    mFalseButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Toast.makeText(QuizActivity.this,R.string.incorrect_toast,Toast.LENGTH_LONG).show();
        }
    });
}

}

See this link:- https://stackoverflow.com/questions/25313054/whats-the-relationship-between-classname-this-and-context-class — InsaneCat, Oct 12 '17 at 13:45
@Selvin I probably do not understand what is instance. I thought that instance is real "object" of some class. For example Cat cat = new Cat(); But where in my code we create this instance? — Владислав Прасков, Oct 12 '17 at 13:53
anonymous class: with `new View.OnClickListener() { someMethod() { } }` you are creating an anonymous class inistance, inside `someMethod()` `this` reffers to this anonymous class instance ... not to outer class (QuizActivity) — Selvin, Oct 12 '17 at 13:55
@Selvin Yes, it's clear. QuizActivity.this refers to instance of QuizActivity. But where we create this instance? QuizActivity quizActivity = new... — Владислав Прасков, Oct 12 '17 at 14:16
It is created by Android OS ... you should never create Application/Service/Activity class by your own ... — Selvin, Oct 12 '17 at 14:17

Does onCreate create an instance of the class?

0 Answers0