变量包含意外值

Question

I'm building a module for checking an answer in my Android java app and it doesn't work. While debugging it shows that the variable holds a value that is completely unexpected for it to hold. Could please someone explain what the problem might be? Here is the module:

private void QuizOperations() {

        Toast.makeText(QuizActivity.this,"quizOperation", Toast.LENGTH_SHORT).show();
        answered = true; // when the question is already answered Set bool to true
        RadioButton rbSelected = findViewById(rbGroup.getCheckedRadioButtonId());
        int indexofchild =rbGroup.indexOfChild(rbSelected) +1;
        int answerNr = indexofchild  +1;
        checkSolution(answerNr,rbSelected);// method checks if the answer that is selected by the user corresponds to the answer in the database
    }

The intended way was rbselected getting the index of the RadioButton pressed by the user, and than answerNr gets the index of this button as int. Than it passes in to the checksolution() function which checks if the AnswerNr corresponds to the right answer in the database. However, while debugging answerNr holds the value of 5 whichever button I press.

Debug screenshot

Let me know if any additional code needed. Thanks a lot

Answer 1

Here is a very minimalistic example on how to detect the view is being pressed, set/get id from tag.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical"
    android:background="#333333">
    <RadioButton
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:id="@+id/radioButton1"/>
    <RadioButton
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:id="@+id/radioButton2"/>
    <RadioButton
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:id="@+id/radioButton3"/>
</LinearLayout>

public class MainActivity extends AppCompatActivity implements View.OnClickListener
{
    private String[] answers = {
        "January",
        "February",
        "March",
    };
    
    private RadioButton rb1, rb2, rb3;
    
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        rb1 = findViewById(R.id.radioButton1);
        rb2 = findViewById(R.id.radioButton2);
        rb3 = findViewById(R.id.radioButton3);
        
        rb1.setTag("0");
        rb2.setTag("1");
        rb3.setTag("2");
        
        rb1.setOnClickListener(this);
        rb2.setOnClickListener(this);
        rb3.setOnClickListener(this);
    }

    @Override
    public void onClick(View view)
    {
        final int index = Integer.parseInt((String)view.getTag());
        switch(view.getId()) {
            case R.id.radioButton1:
                rb2.setChecked(false);
                rb3.setChecked(false);
                Toast.makeText(MainActivity.this, answers[index], Toast.LENGTH_SHORT).show();
            break;
            case R.id.radioButton2:
                rb1.setChecked(false);
                rb3.setChecked(false);
                Toast.makeText(MainActivity.this, answers[index], Toast.LENGTH_SHORT).show();
            break;
            case R.id.radioButton3:
                rb1.setChecked(false);
                rb2.setChecked(false);
                Toast.makeText(MainActivity.this, answers[index], Toast.LENGTH_SHORT).show();
            break;
        }
    }
}