没有这样的实例字段 [英] No such instance field

问题描述

我正在尝试让我的应用程序在使用 onSaveInstanceState 更改屏幕方向时保存一些数据以保存布尔值 mCheated 。

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.

我设置了很多断点，并且变量视图中的 mCheated 布尔值出现错误

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'

我不知道为什么我在活动开始时声明值为false，如果按下按钮则将其更改为true。任何人都可以帮我吗？

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);
    }
}

推荐答案

它事实证明代码没有问题，Android Studio需要重启。我认为这取决于我克隆了项目的事实，并且可能使用了以前版本中的错误文件。

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.

这篇关于没有这样的实例字段的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！