Question

我正在开发一款Android游戏，希望使用SQLite保存高分。到目前为止，我已经为SQL表做了一个单独的类，如下所示：

public class SQLclass {
public final static String KEY_ROWID = "_id";
public final static String KEY_NAME = "person_name";
public final static String KEY_SCORE = "person_score";

private final static String DATABASE_NAME = "Scoredb";
private final static String DATABASE_TABLE = "scoreTable";
private final static int DATABASE_VERSION = 1;

private DbHelper ourScore;
private final Context ourContext;
private SQLiteDatabase ourDatabase;

private static class DbHelper extends SQLiteOpenHelper{

    public DbHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        // TODO Auto-generated constructor stub
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        db.execSQL( "CREATE TABLE " + DATABASE_TABLE + " (" +
        KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + 
        KEY_NAME + " TEXT NOT NULL, " +
        KEY_SCORE + " TEXT NOT NULL);"
        );
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
        onCreate(db);

    }

}
public SQLclass(Context c)
{
    ourContext = c;
}

public SQLclass open() throws SQLException{
    ourScore = new DbHelper(ourContext);
    ourDatabase = ourScore.getWritableDatabase();
    return this;
}
public void close(){
    ourScore.close();
}

public long createEntry(String nameString, String scoreString) {
    // TODO Auto-generated method stub
    ContentValues cv = new ContentValues();
    cv.put(KEY_NAME, nameString);
    cv.put(KEY_SCORE, scoreString);
    return ourDatabase.insert(DATABASE_NAME, null, cv);
}

public String getData() {
    // TODO Auto-generated method stub
    String[] columns = new String[]{KEY_ROWID, KEY_NAME, KEY_SCORE};
    Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
    String result = "";
    int Row = c.getColumnIndex(KEY_ROWID);
    int name = c.getColumnIndex(KEY_NAME);
    int score = c.getColumnIndex(KEY_SCORE);

    for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
        result = result + c.getString(Row) + " " + c.getString(name) + " " + c.getString(score) + "\n";
    }

    return result;
}

然后我实现了在两种不同的活动中写入数据和接收数据的方法。

NameString = Name.getText().toString();
        ScoreString = count;
        SQLclass entry = new SQLclass(NewScore.this);
        entry.open();
        entry.createEntry(NameString, ScoreString);
        entry.close();

所以我将数据保存在2列中，一列是名称，另一列是得分检索：

SQLclass info = new SQLclass(this);
info.open();
String data = info.getData();
        info.close();
        tv.setText(data);

我觉得我正在做的是正确的，但由于某种原因，数据既没有保存也没有加载。

跨活动的SQLite存储

0 个答案: