java - 关闭后保存奖励广告值(value)

Question

观看激励广告视频后， TextView 会显示奖励积分。每个视频后积分都会累积。但是，当应用程序关闭时，积分将被删除。我希望当用户返回应用程序时继续显示这些点。我无法弄清楚这是否是 onDestroy 方法或 savinginstance 的一部分。

    public class ProfileActivity extends AppCompatActivity implements RewardedVideoAdListener {

    TextView mText, userEmail;
    private int pointCount;

    private TextView dateTimeDisplay;
    private Calendar calendar;
    private SimpleDateFormat dateFormat;
    private String date;

    Button userLogout;
    Button goToHome;
    ImageView ivQR;
    private AdView mAdView;
    FirebaseAuth firebaseAuth;
    FirebaseUser firebaseUser;
    FirebaseDatabase firebaseDatabase;
    DatabaseReference databaseReference;
    private RewardedVideoAd mRewardedVideoAd;

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

     //rewards ads
        //ca-app-pub-9125010107042455/6647636731 actual
        //ca-app-pub-3940256099942544~3347511713 for testing
        MobileAds.initialize(getApplicationContext(), ("ca-app-pub-9125010107042455/6647636731"));
        // Use an activity context to get the rewarded video instance.
        mRewardedVideoAd = MobileAds.getRewardedVideoAdInstance(this);
        mRewardedVideoAd.setRewardedVideoAdListener(this);

        //points count
        mText = findViewById(R.id.textView);
        pointCount = 0;
        mText.setText("Points: " + pointCount);

        loadRewardedVideoAd();

     private void loadRewardedVideoAd (){

        if (!mRewardedVideoAd.isLoaded()){
            //ca-app-pub-9125010107042455/6647636731 actual
            //ca-app-pub-3940256099942544/5224354917 for testing
            mRewardedVideoAd.loadAd("ca-app-pub-3940256099942544/5224354917",new AdRequest.Builder().build());
        }
    }

    public void startVideoAd(View view){
        if(mRewardedVideoAd.isLoaded()){
            mRewardedVideoAd.show();
        }
    }

    @Override
    public void onRewardedVideoAdLoaded() {

    }

    @Override
    public void onRewardedVideoAdOpened() {

    }

    @Override
    public void onRewardedVideoStarted() {

    }

    @Override
    public void onRewardedVideoAdClosed() {

        loadRewardedVideoAd();

    }

    private void addPoints(int points) {
        pointCount +=  points;
        mText.setText("Points: " + pointCount);
    }

    @Override
    public void onRewarded(RewardItem rewardItem) {

        Toast.makeText(ProfileActivity.this, "🔥 Points 🔥", Toast.LENGTH_SHORT).show();
        addPoints(rewardItem.getAmount());

    }

    @Override
    public void onRewardedVideoAdLeftApplication() {

    }

    @Override
    public void onRewardedVideoAdFailedToLoad(int i) {

    }

    @Override
    protected void onPause() {
        mRewardedVideoAd.pause(this);
        super.onPause();
    }

    @Override
    protected void onResume() {
        mRewardedVideoAd.resume(this);
        super.onResume();

    }

    @Override
    protected void onDestroy() {
        mRewardedVideoAd.destroy(this);
        super.onDestroy();
    }

    @Override
    public void onRewardedVideoCompleted() {

    }
}

Answer 1

您应该使用onSaveInstanceState(Bundle savingInstanceState)方法来保存点数。

您可以通过执行以下操作来实现:

//This is what will be used to recognize your number of points in the saved bundle.
static final String POINTS = "pointCount";

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
    // Save your number of points
    savedInstanceState.putInt(POINTS, pointCount);

    super.onSaveInstanceState(savedInstanceState);
}

然后调用onRestoreInstanceState(Bundle savingInstanceState)方法即可恢复点数。

public void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);

    // Restore your number of points and store them in your variable
    pointCount = savedInstanceState.getInt(POINTS);
}

如果需要进一步解释，请引用官方文档https://developer.android.com/guide/components/activities/activity-lifecycle#java