Java Android基本遊戲 - 使用共享偏好保存HighScore - TOTAL BEGINNER

Question

我是初學Java的Java程序員。我使用Eclipse創建了一個基本的Android遊戲，我想保存高分。我被告知要使用共享偏好，所以當我退出遊戲並再次打開遊戲時，會保存高分。我已經獲得了高分，可以保存在我的「主菜單」頁面上，但對共享首選項代碼的放置位置感到困惑？它應該在我的OnCreate中嗎？請看我的代碼，並嘗試幫助我。我知道它可能非常簡單，但我一直在這方面工作了一段時間。

下面的代碼：

package cct.mad.lab; 

import android.os.Bundle; 
import android.app.Activity; 
import android.content.Context; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.content.SharedPreferences.Editor; 
import android.graphics.Bitmap; 
import android.graphics.drawable.BitmapDrawable; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 
import android.widget.Button; 
import android.widget.ImageView; 
import android.widget.TextView; 
import android.widget.Toast; 
import cct.mad.lab.GameView; 
import android.media.AudioManager; 
import android.media.MediaPlayer; 
import android.media.SoundPool; 
import android.net.Uri; 

public class MainMenu extends Activity { 

    //MediaPlayer backgroundmusic;//////////////////// 

    private static final int SCORE_REQUEST_CODE = 1;// The request code for the intent 

    private static final int PREFERENCE_MODE_PRIVATE = 0; 

    TextView tvHighScore; 
    TextView tvLastScore; 
    //TextView tvScore 
    String score; 
    Intent gameIntent; 
    int HighNum = 0; 
    SoundPool sp; 
    MediaPlayer mp; 
    int hit = 0; 
    ImageView crash; 
    ImageView image; 
    //int highscore = 0; 



    protected void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.game_start); 
     tvHighScore = (TextView) findViewById(R.id.tvGuessGame); 
     tvLastScore = (TextView) findViewById(R.id.LastGameNumb); 


    } 

    public void startGame(View v) 

    { 
     gameIntent = new Intent(this,GameActivity.class); 
     startActivityForResult(gameIntent, SCORE_REQUEST_CODE); 

     mp = MediaPlayer.create(this, R.raw.bgmusic); // Assigns the media player to the bgmusic in the raw flder 
     mp.setLooping(true); // loops the media player so it continues to play 
     mp.start(); // starts the media player when the start game button is called 
    } 


    /* Create Options Menu */ 
    public boolean onCreateOptionsMenu(Menu menu) 
    { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.main_menu, menu); 
     return true; 
    } 


    // Respond to item selected on OPTIONS MENU 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle item selection 
     switch (item.getItemId()) { 
     //put data in Intent 
     case R.id.easy: 
      Toast.makeText(this, "Easy chosen", Toast.LENGTH_SHORT).show(); 
      return true; 
     case R.id.medium: 
      Toast.makeText(this, "Medium chosen", Toast.LENGTH_SHORT).show(); 
      return true; 
     case R.id.hard: 
      Toast.makeText(this, "Hard chosen", Toast.LENGTH_SHORT).show(); 
      return true; 
     case R.id.other: 
      Toast.makeText(this, "Other chosen", Toast.LENGTH_SHORT).show(); 
      return true; 
     default: 
      return super.onOptionsItemSelected(item); 
     } 
    } 


    protected void onActivityResult(int requestCode, int resultCode, Intent retIntent) { 

    mp.pause(); // Pauses the Mediaplayer when the game is stopped and returned to the main menu. 

     // Check which request we're responding to 
     if (requestCode == SCORE_REQUEST_CODE) { 
      // Make sure the request was successful 
      if (resultCode == RESULT_OK) { 
       if (retIntent.hasExtra("GAME_SCORE")) 
       { 
        int scoreFromGame = retIntent.getExtras().getInt("GAME_SCORE"); 

        if (scoreFromGame > HighNum) 
        { 
        tvHighScore.setText(Integer.toString(scoreFromGame)); 
        tvLastScore.setText(Integer.toString(scoreFromGame)); 
        HighNum = scoreFromGame; 
        } 

        else if (scoreFromGame > HighNum) 
        { 
         tvHighScore.setText(Integer.toString(scoreFromGame)); 
         tvLastScore.setText(Integer.toString(scoreFromGame)); 
        } 

        else if (scoreFromGame < HighNum) 
        { 
         tvLastScore.setText(Integer.toString(scoreFromGame)); 
        } 
       } 
      } 
     } 

    } 


    @Override 
    protected void onDestroy() { 
     // TODO Auto-generated method stub 
     super.onDestroy(); 
     mp.stop(); // Stops the mediaplayer when the game/emulator is exited. 
     mp.release(); // Stops the mediaplayer when the game/emulator is exited. 
    } 







    /* 
    @Override 
    public void onSaveInstanceState(Bundle savedInstanceState){ // When activity stops, system calls onSaveInstancState to save info. 
     //Save the user's current game state 
     savedInstanceState.putInt("GAME_SCORE", HighNum); 
     super.onSaveInstanceState(savedInstanceState); //Calls superclass to view the hierachy state 
    } 

    @Override 
    public void onRestoreInstanceState(Bundle savedInstanceState){ 
     super.onCreate(savedInstanceState); // Calls the superclass first 

     if (savedInstanceState != null) { 
      HighNum = savedInstanceState.getInt("GAME_SCORE"); 
     } else { 



     } 

     super.onRestoreInstanceState(savedInstanceState); 
    } 



    */ 




} 

Answer 1

你應該看看Android Activity lifecycle如果不充分了解活動的生命週期。該圖像顯示了您的活動可以處於的狀態以及您在這些狀態之間切換的功能。

你應該能夠保存首選項中的onPause，並加載偏好您的活動類的onResume功能。這意味着您的偏好將在活動關閉/打開時保存/加載。