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我正在做一个测验应用程序。为问题创建的数据库正在 pc 上运行，但是当我在 android 手机中传输 .apk 文件时，它没有从数据库中获取任何数据并显示强制关闭。

在此站点上搜索后，我发现将数据库文件放在资产文件夹中，但这不起作用。

我无法识别为什么应用程序没有在手机中运行？下面是数据库文件的代码。如果有机会在设备上运行应用程序，请告诉我。

public class DatabaseFile extends SQLiteOpenHelper {
private static String DB_PATH = "/data/data/com.example.quizproject/databases/";
public static final String DATABASE_NAME="Quiz.db";
public static final String QUES="ques";
public static final String OP1="op1";
public static final String OP2="op2";
public static final String OP3="op3";
public static final String ANS="ans";
public static final String NAME="name";
public static final String CANS="cans";
public static final String SCORE="score";
private final Context myContext;
private SQLiteDatabase myDataBase; 

public DatabaseFile(Context context) {

super(context, DATABASE_NAME, null, 1);
this.myContext = context;
}

public void createDataBase() throws IOException{

     boolean dbExist = checkDataBase();

     if(dbExist){
      //do nothing - database already exist
     }else{
         this.getReadableDatabase();

         try {

       copyDataBase();

      } catch (IOException e) {

          throw new RuntimeException(e);

         }
     }

    }

    private boolean checkDataBase(){

     SQLiteDatabase checkDB = null;

     try{
      String myPath = DB_PATH + DATABASE_NAME;
      checkDB = SQLiteDatabase.openDatabase(myPath, null,   SQLiteDatabase.OPEN_READONLY);

     }catch(SQLiteException e){

      //database does't exist yet.

     }

     if(checkDB != null){

      checkDB.close();

     }

     return checkDB != null ? true : false;
    }

    private void copyDataBase() throws IOException{

     //Open your local db as the input stream
     InputStream myInput = myContext.getAssets().open(DATABASE_NAME);

     // Path to the just created empty db
     String outFileName = DB_PATH + DATABASE_NAME;

     //Open the empty db as the output stream
     OutputStream myOutput = new FileOutputStream(outFileName);

     //transfer bytes from the inputfile to the outputfile
     byte[] buffer = new byte[1024];
     int length;
     while ((length = myInput.read(buffer))>0){
      myOutput.write(buffer, 0, length);
     }

     //Close the streams
     myOutput.flush();
     myOutput.close();
     myInput.close();

    }

    public void openDataBase() {

     //Open the database
        String myPath = DB_PATH + DATABASE_NAME;
     myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
    }
    @Override
     public synchronized void close() {
             if(myDataBase != null)
              myDataBase.close();
             super.close();
     }
public void onCreate(SQLiteDatabase db) {

//db.execSQL("CREATE TABLE quiztable (_id INTEGER PRIMARY KEY AUTOINCREMENT," +
    //  "ques TEXT, op1 TEXT, op2 TEXT, op3 TEXT, ans TEXT);");




}



@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // TODO Auto-generated method stub

}

}
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