Introduction of Sharedpreference in tap counter app causes app crash

问题

I'm trying to do a basic tap counter app that stores counter value to sharedpreference. App works as normal as a tap counter without sharedpreference when I run it, but when I introduce sharedpreference, the app crashes.

~MainActivity~

public class MainActivity extends AppCompatActivity {

public static final String PREFS = "examplePrefs";
Button btn_tap, btn_trophy, btn_reset;
TextView tv_tapped, tv_times, tv_tap1;
private int counter = 0;

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

    btn_tap = (Button) findViewById(R.id.btn_tap);
    btn_trophy = (Button) findViewById(R.id.btn_trophy);
    btn_reset = (Button) findViewById(R.id.btn_reset);
    tv_tap1 = (TextView) findViewById(R.id.tv_tap1);
    tv_tapped = (TextView) findViewById(R.id.tv_tapped);
    tv_times = (TextView) findViewById(R.id.tv_times);

    SharedPreferences example = getSharedPreferences(PREFS, counter);
    int valueString = example.getInt("userValue", 0);
    tv_tapped.setText(valueString);

    btn_tap.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            counter +=1;
            tv_tapped.setText(counter);
            tv_tapped.setTextColor(Color.BLUE);

            SharedPreferences example = getSharedPreferences(PREFS, counter);
            SharedPreferences.Editor editor = example.edit();
            editor.putInt("userValue", counter);
            editor.commit();

        }
    });
    btn_reset.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            counter = 0;
            tv_tapped.setText(counter);
            tv_tapped.setTextColor(Color.RED);
        }
    });

    btn_trophy.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i = new Intent(MainActivity.this, TrophyActivity.class);
            startActivity(i);
        }
    });

  }
}

The second activity gets the value from sharedpreference and displays the trophy level name, like 1-25 = beginner, 26-50 = intermediate etc it's in the code, which i don't think has a problem but doesn't hurt if you see it.

~TrophyActivity~

public class TrophyActivity extends AppCompatActivity {

public static final String PREFS = "examplePrefs";
Button btn_back, btn_exit;
TextView tv_congrats, tv_received, tv_trophyName, tv_trophy;
ImageView iV_trophy;

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

    btn_back = (Button) findViewById(R.id.btn_back);
    btn_exit = (Button) findViewById(R.id.btn_exit);
    tv_congrats = (TextView) findViewById(R.id.tv_congratulations);
    tv_received = (TextView) findViewById(R.id.tv_received);
    tv_trophyName = (TextView) findViewById(R.id.tv_trophy_name);
    tv_trophy = (TextView) findViewById(R.id.tv_trophy);
    iV_trophy = (ImageView) findViewById(R.id.iV_trophy);

    SharedPreferences example = getSharedPreferences(PREFS, MODE_PRIVATE);
    int valueString = example.getInt("userValue", 0);

    if (valueString<=25){
        tv_trophyName.setText("Beginner");
        iV_trophy.setImageResource(R.drawable.ic_beginner);
    }else if (valueString<=50){
        tv_trophyName.setText("Intermediate");
        iV_trophy.setImageResource(R.drawable.ic_ntermediate);
    }else if (valueString<=75){
        tv_trophyName.setText("Semi Jumbo");
        iV_trophy.setImageResource(R.drawable.ic_semi_jumbo);
    }else if (valueString<=100){
        tv_trophyName.setText("Jumbo");
        iV_trophy.setImageResource(R.drawable.ic_jumbo);
    }

    btn_back.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            TrophyActivity.super.onBackPressed();
        }
    });

    btn_exit.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            moveTaskToBack(true);
            android.os.Process.killProcess(android.os.Process.myPid());
            System.exit(1);
        }
    });

  }
}

Thank you for your help in advance !!! :-)

回答1:

TextView and int are not good friends so use:

tv_tapped.setText(String.valueOf(valueString)); // will convert the int to String
tv_tapped.setText(String.valueOf(counter));     // another case

when you pass an int what Android does is , from void setText (int resid)

Sets the text to be displayed using a string resource identifier

so since there will be no resource match found because it's just a random number passed by you so hence exception

来源：https://stackoverflow.com/questions/44707204/introduction-of-sharedpreference-in-tap-counter-app-causes-app-crash

标签

android

sharedpreferences