Question

我正在开发一个测验游戏。我知道sqlite数据库创建和DBhandler等的使用..但是，问题是我找不到如何在我的android项目中在资源文件夹中创建数据库文件。请帮助我。提前致谢

Answer 1

您可以使用Jeff Gilfelt的SQliteAssetHelper。 SQLiteAssetHelper的GitHub主页提供了详细记录的设置和使用信息。

Answer 2

这是我现在得到的解决方案。为了存储任何类型的数据，我们必须创建可以由任何sqlite数据库浏览器创建的db文件，例如 this

创建数据库后，将其导入android项目的assets文件夹，并使用以下命令访问它：

 //The Android's default system path of the application's database.
private static String DB_PATH = "/data/data/com.brainstorm/databases/";

private static String DB_NAME = "Brainstorm.db";

private SQLiteDatabase myDataBase; 

private final Context myContext;


 /* Constructor
 * Takes and keeps a reference of the passed context in order to access to the application assets and resources.
 * @param context
 */
public DataBaseHelper(Context context) {

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

/**
 * Creates a empty database on the system and rewrites it with your own database.
 * */
public void createDataBase() throws IOException{

    boolean dbExist = checkDataBase();

    if(dbExist){
        //do nothing - database already exist
    }
    else{

        //By calling this method and empty database will be created into the default system path
           //of your application so we are going to be able to overwrite that database with our database.
        this.getReadableDatabase();

        try {

            copyDataBase();

        } catch (IOException e) {

            throw new Error("Error copying database");

        }
    }

}

/**
 * Check if the database already exist to avoid re-copying the file each time you open the application.
 * @return true if it exists, false if it doesn't
 */
private boolean checkDataBase(){

    SQLiteDatabase checkDB = null;

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

    }catch(SQLiteException e){

        //database does't exist yet.
        Log.e("DBHelper", "DataBase Does Not Exist closing returning null");

    }

    if(checkDB != null){

        Log.e("DBHelper", "DataBase Exists closing checkDB");
        checkDB.close();

    }

    return checkDB != null ? true : false;
}

/**
 * Copies your database from your local assets-folder to the just created empty database in the
 * system folder, from where it can be accessed and handled.
 * This is done by transferring byte-stream.
 * */
private void copyDataBase() throws IOException{

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

    // Path to the just created empty db
    String outFileName = DB_PATH + DB_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() throws SQLException{

    //Open the database
    String myPath = DB_PATH + DB_NAME;
    myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);

}

@Override
public synchronized void close() {

        if(myDataBase != null)
            myDataBase.close();

        super.close();

}

如何使用sqlite在Android游戏中存储100多个问题数据

2 个答案: