我有一个微调器，它使用EditText动态获取其项目。它存储在SQLite中。如何在开始时添加单个项目？

Question

我正在尝试添加一个对Spinner没有任何价值的项目。我希望用户在活动开始时看到“选择项目”。如何在onCreate中向spinner添加单个项目？请记住，用户可以使用按钮动态地向微调器添加项目并编辑文本。 Rite现在是微调器中的第一件事是添加到数据库的第一个项目。如果没有向数据库添加任何内容，则微调器为空。

这是我的代码

MainActivty

public class MainActivity extends Activity implements OnItemSelectedListener {

Button AddBtn;
EditText et;
EditText cal;
Spinner spn;

SQLController SQLcon;
ProgressDialog PD;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    AddBtn = (Button) findViewById(R.id.addbtn_id);
    et = (EditText) findViewById(R.id.et_id);
    cal = (EditText) findViewById(R.id.et_cal);
    spn = (Spinner) findViewById(R.id.spinner_id);
    spn.setOnItemSelectedListener(this);
    SQLcon = new SQLController(this);
    // opening database
    SQLcon.open();

    loadtospinner();

    AddBtn.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            new MyAsync().execute();

        }
    });
}

public void loadtospinner() {

    Cursor c = SQLcon.readData();
    ArrayList<String> al = new ArrayList<String>();

    c.moveToFirst();
    while (!c.isAfterLast()) {

        String name = c.getString(c.getColumnIndex(DBhelper.MEMBER_NAME));

        al.add(name);

        c.moveToNext();
    }

    ArrayAdapter<String> aa1 = new ArrayAdapter<String>(
            getApplicationContext(), R.layout.spinner_item, R.id.textView1,
            al);

    spn.setAdapter(aa1);

    // closing database
    SQLcon.close();

}

private class MyAsync extends AsyncTask<Void, Void, Void> {

    @Override
    protected void onPreExecute() {

        super.onPreExecute();
        PD = new ProgressDialog(MainActivity.this);
        PD.setTitle("Please Wait..");
        PD.setMessage("Loading...");
        PD.setCancelable(false);
        PD.show();
    }

    @Override
    protected Void doInBackground(Void... params) {
        String name = et.getText().toString();
        String calories = cal.getText().toString();
        // opening database
        SQLcon.open();
        // insert data into table
        SQLcon.insertData(name, calories);

        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        super.onPostExecute(result);
        loadtospinner();
        PD.dismiss();
    }
}

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position,
        long id) {

    String getName;
    getName = "";
    String getCalories;
    getCalories = "";

    SQLController handlerInfo = new SQLController(getBaseContext());
    handlerInfo.open();
    Cursor cursor = handlerInfo.readData();
    if (cursor.moveToFirst()) {
        do {
            getName = cursor.getString(1);
            getCalories = cursor.getString(2);

        } while (cursor.moveToNext());
    }

    handlerInfo.close();

    // Showing selected spinner item
    Toast.makeText(parent.getContext(), "You selected: " + getCalories,
            Toast.LENGTH_LONG).show();

}

@Override
public void onNothingSelected(AdapterView<?> arg0) {
    // TODO Auto-generated method stub

}

}

数据库和助手

public class DBhelper extends SQLiteOpenHelper {

// TABLE INFORMATTION
public static final String TABLE_MEMBER = "member";
public static final String MEMBER_ID = "_id";
public static final String MEMBER_NAME = "name";
public static final String KEY_CALORIES = "calories";

// DATABASE INFORMATION
static final String DB_NAME = "MEMBER.DB";
static final int DB_VERSION = 2;

// TABLE CREATION STATEMENT
private static final String CREATE_TABLE = "create table " + TABLE_MEMBER
        + "(" + MEMBER_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
        + MEMBER_NAME + " TEXT NOT NULL," + KEY_CALORIES
        + " INT NOT NULL);";

public DBhelper(Context context) {
    super(context, DB_NAME, null, DB_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL(CREATE_TABLE);
}

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

    db.execSQL("DROP TABLE IF EXISTS " + TABLE_MEMBER);
    onCreate(db);
}
}

数据库和助手

public class SQLController {
private DBhelper dbhelper;
private Context ourcontext;
private SQLiteDatabase database;

public SQLController(Context c) {
    ourcontext = c;
}

public SQLController open() throws SQLException {
    dbhelper = new DBhelper(ourcontext);
    database = dbhelper.getWritableDatabase();
    return this;

}

public void close() {
    dbhelper.close();
}

public void insertData(String name, String calories) {
    ContentValues cv = new ContentValues();
    cv.put(DBhelper.MEMBER_NAME, name);
    cv.put(DBhelper.KEY_CALORIES, calories);
    database.insert(DBhelper.TABLE_MEMBER, null, cv);
}

public Cursor readData() {
    String[] allColumns = new String[] { DBhelper.MEMBER_ID,
            DBhelper.MEMBER_NAME, DBhelper.KEY_CALORIES };
    Cursor c = database.query(DBhelper.TABLE_MEMBER, allColumns, null,
            null, null, null, null);
    if (c != null) {
        c.moveToFirst();
    }
    return c;
}

}