在一個TextView

Question

Int的SharedPreferences保存價值我儘量節省使用SharedPreferences在TextView中顯示一個int值，它不能在所有的工作。我做了一個簡單的小例子代碼：

public class MainActivity extends Activity { 

Button search; 
TextView tvRing; 
int redRing; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    final SharedPreferences prefs = getSharedPreferences("sharedPreferences", Context.MODE_PRIVATE); 

    search = (Button) findViewById(R.id.radar); 
    tvRing = (TextView) findViewById(R.id.ring); 

    int someint = prefs.getInt("someint", 0); 
    tvRing.setText("Objects found : " + String.valueOf(someint)); 

    search.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      addRing(); 
      SharedPreferences.Editor editor = prefs.edit(); 
      editor.putInt("someint", redRing); 
      editor.commit(); 
     } 
    }); 
} 

public void addRing() { 
    redRing++; 
} 
} 

謝謝大家的幫助。

Answer 1

我解釋說，我所做的更改

public class MainActivity extends Activity { 

    Button search; 
    TextView tvRing; 

    //Making sharedpreferences and integers global for ease of use 
    private SharedPreferences prefs; 
    private int redRing, someint; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     search = (Button) findViewById(R.id.radar); 
     tvRing = (TextView) findViewById(R.id.ring); 

     //Someint default value is 0 if not ever saved before 
     prefs = getSharedPreferences("sharedPreferences", Context.MODE_PRIVATE); 
     someint = prefs.getInt("someint", 0); 
     tvRing.setText("Objects found : " + String.valueOf(someint)); 

     search.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       //Load the lates someint in onclick 
       someint = prefs.getInt("someint", 0); 

       //redring is the dummy integer to increment someint 
       redRing=someint+1; 
       //Save the incremented value 
       SharedPreferences.Editor editor = prefs.edit(); 
       editor.putInt("someint", redRing); 
       editor.commit(); 

       //To show the latest number on the tv 
       lastNumber(); 
      } 
     }); 
    } 


    public void lastNumber() { 
     prefs = getSharedPreferences("sharedPreferences", Context.MODE_PRIVATE); 
     someint = prefs.getInt("someint", 0); 
     tvRing.setText("Objects found : " + String.valueOf(someint)); 
    } 
} 

Answer 2

您應該使用

SharedPreferences.Editor editor = prefs.edit(); 
     editor.putInt("someint", redRing); 
     editor.apply(); 

，你永遠不會使用 「someint」，使用

tvRing.setText(String.valueOf(someint));