For the life of me, I can't seem to figure out why ImageButton is not working

Android Programming (3rd Edition) 2. Android and Model-View-Controller
1

This is for the last challenge of Chapter 2: MVC
LogCat shows this error whenever I run the app. It crashes immediately.
Caused by: java.lang.ClassCastException: androidx.appcompat.widget.AppCompatButton cannot be cast to android.widget.ImageButton

Couldn’t figure out how to condense code so I had to copy and paste directly.

QUIZACTIVITY:
package com.bignerdranch.andoid.geoquiz;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;

import static com.bignerdranch.andoid.geoquiz.R.id.question_text_view;

public class QuizActivity extends AppCompatActivity {

private Button mTrueButton;
private Button mFalseButton;
private ImageButton mPrevButton;
private ImageButton mNextButton;
private TextView mQuestionTextView;

//Store question list into Question array to access later.
private Question[] mQuestionBank = new Question[] {
        new Question(R.string.question_australia, true),
        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),
        new Question(R.string.question_canada, true),
};
//Keep count of questions in the Question array.
private int mCurrentIndex = 0;

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

    //Listener for TextView object. Every time it is pressed, the next question is displayed.
    mQuestionTextView = (TextView) findViewById(question_text_view);
    mQuestionTextView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mCurrentIndex = (mCurrentIndex + 1) % mQuestionBank.length;
            updateQuestion();
        }
    });

    //Listener for true button. Displays correct toast if answer is right.
    mTrueButton = (Button) findViewById(R.id.true_button);
    mTrueButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
           checkAnswer(true);
        }
    });

    //Listener for false button. Displays incorrect toast if answer is wrong.
    mFalseButton = (Button) findViewById(R.id.false_button);
    mFalseButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
           checkAnswer(false);
        }
    });

    //Listener for prev button. Displays the previous question stored in Question array when Prev Button is pressed.
    mPrevButton = (ImageButton) findViewById(R.id.prev_button);
    mPrevButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if(mCurrentIndex == 0) {
              mCurrentIndex = mCurrentIndex + (mQuestionBank.length - 1);
            }
            else {
                  mCurrentIndex = (mCurrentIndex - 1) % mQuestionBank.length;
            }
            updateQuestion();
      }
    });

    //Listener for next button. Displays next question stored in Question array when Next Button is pressed.
    mNextButton = (ImageButton) findViewById(R.id.next_button);
    mNextButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mCurrentIndex = (mCurrentIndex + 1) % mQuestionBank.length;
            updateQuestion();
        }
    });

    updateQuestion();
}
//Updates questions.
private void updateQuestion() {
    int question = mQuestionBank[mCurrentIndex].getTextResId();
    mQuestionTextView.setText(question);
}
//Checks if answer to the questions are right or wrong.
private void checkAnswer(boolean userPressedTrue) {
    boolean answerIsTrue = mQuestionBank[mCurrentIndex].isAnswerTrue();

    int messageResId = 0;

    if(userPressedTrue == answerIsTrue) {
        messageResId = R.string.correct_toast;
    }
    else {
        messageResId = R.string.incorrect_toast;
    }
    Toast.makeText(this, messageResId, Toast.LENGTH_SHORT)
            .show();
}

}

quiz_acitivity.xml:

<TextView
    android:id="@+id/question_text_view"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="24dp" />

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal">

    <Button
        android:id="@+id/true_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/true_button" />

    <Button
        android:id="@+id/false_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/false_button" />
</LinearLayout>

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal">

    <ImageButton
        android:id="@+id/prev_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/arrow_left"
        android:contentDescription="@null" />


    <ImageButton
        android:id="@+id/next_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/arrow_right"
        android:contentDescription="@null" />

</LinearLayout>

Logtcat:

2020-01-08 16:46:58.054 3974-3974/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.bignerdranch.andoid.geoquiz, PID: 3974
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.bignerdranch.andoid.geoquiz/com.bignerdranch.andoid.geoquiz.QuizActivity}: java.lang.ClassCastException: androidx.appcompat.widget.AppCompatButton cannot be cast to android.widget.ImageButton
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
Caused by: java.lang.ClassCastException: androidx.appcompat.widget.AppCompatButton cannot be cast to android.widget.ImageButton
at com.bignerdranch.andoid.geoquiz.QuizActivity.onCreate(QuizActivity.java:69)
at android.app.Activity.performCreate(Activity.java:6662)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599)

2

Your code looks correct, the only thing that is strange is your layout file.
In onCreate method you setting the layout to “activity_quiz.xml”,
line 38: setContentView(R.layout.activity_quiz),
but your layout file should be named “quiz_acitivity.xml”.
Do you maybe have more layout files and just setting up the wrong one?

3

Yes, I believe that was the issue. I deleted the orginal file because for some reason the compiler was showing errors even though the code was correct. Then I created a new layout file and the errors were resolved briefly until I started using ImageButton. For some reason every time I ran the app, it would sometimes create the older layout with the text inside the previous and next buttons or just crash. Turns out I did have more than one layout file after checking the project files. Ended up creating a new project and copy and pasting the code over. Works perfectly now. Thank you for pointing that out.