No such instance field

Question

I'm trying to get my application to save some data when the orientation of the screen is changed using the onSaveInstanceState to save a boolean value mCheated.

I've set numerous break points and am getting an error for the mCheated boolean value in the variables view

mCheated= No such instance field: 'mCheated'

I have no idea why as I declare it with a value false when the activity is started and change it to true if a button is pressed. Can anyone help me out?

package com.bignerdranch.android.geoquiz;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

/**
 * Created by Chris on 20/02/2015.
 */
public class CheatActivity extends Activity {

    public static final String EXTRA_ANSWER_IS_TRUE = "com.bignerdranch.android.geoquiz.answer_is_true";
    public static final String EXTRA_ANSWER_SHOWN = "com.bignerdranch.android.geoquiz.answer_shown";

    private static final String KEY_INDEX = "index";

    private boolean mAnswerIsTrue;

    private TextView mAnswerTextView;
    private Button mShowAnswer;

    private boolean mCheated = false;

    private void setAnswerShownResult(boolean isAnswerShown) {
        Intent data = new Intent();
        data.putExtra(EXTRA_ANSWER_SHOWN, isAnswerShown);
        setResult(RESULT_OK, data);
    }

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

        mAnswerIsTrue = getIntent().getBooleanExtra(EXTRA_ANSWER_IS_TRUE,false);

        if (savedInstanceState != null){
            mCheated = savedInstanceState.getBoolean(KEY_INDEX, mCheated);
        }
        setAnswerShownResult(mCheated);

        mAnswerTextView = (TextView)findViewById(R.id.answerTextView);
        mShowAnswer = (Button)findViewById(R.id.showAnswerButton);
        mShowAnswer.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (mAnswerIsTrue) {
                    mAnswerTextView.setText(R.string.true_button);
                }
                else {
                    mAnswerTextView.setText(R.string.false_button);
                }
                setAnswerShownResult(true);
                mCheated = true;
            }
        });

    }

    @Override
    public void onSaveInstanceState(Bundle savedInstanceState){
        super.onSaveInstanceState(savedInstanceState);
        //Log.i(TAG, "onSaveInstanceState");
        savedInstanceState.putBoolean(KEY_INDEX, mCheated);
    }
}

Answer 1

It turns out there wasn't a problem with the code and that Android Studio required a restart. I think it was down to the fact I had cloned the project and was possibly using an incorrect file from the previous version.

Answer 2

I got the same error and I wasted my 3-4 hours to resolve same error finally I got to know why that happened and it was interesting

1. In my case, I changed the code in one file (I declared one variable and initialized it)

2. I run the apk from my device and attached debugger from android studio

3. I set debug point to that newly added variable where I assigned data to it

4. but during debugging it shows me same error

5. Then I got to know I changed the code in file but I run the apk from device, and I attached debugger I need to compile and run the changes instead of it how it will reflect in apk that was the actual issue

6. So I compiled and ran the code and installed newly compiled apk on device then I attached debugger and it worked for me

hope this will save someone's time

Answer 3

Check if your build variant in Android Studio has

• debuggable as true
• proguard is disabled or commented out.

Answer 4

If you're using pro-guard and obfuscation is true. you have to comment out obfuscation in build gradle

eg: add this in the pro-guard -dontobfuscate

Answer 5

I had the same error. The solution to the error is to disable the Proguard in build.gradle file.

 debug {
        minifyEnabled false
}

Answer 6

In case this comes in handy for anyone else, I was able to resolve this issue immediately once I realized I was in 'Release' mode, not 'Debug' mode, in the Build Variants section.