java绑定微调器后，如何不选择第一项？

Question

public void DatabaseConn(){
DataBaseHelper myDbHelper = new DataBaseHelper(this.getApplicationContext());
myDbHelper = new DataBaseHelper(this);
try { 
myDbHelper.createDataBase();  
} catch (IOException ioe) { 
throw new Error("Unable to create database"); 
}  
try {  
myDbHelper.openDataBase();         
}catch(SQLException sqle){  
throw sqle;  
}

SQLiteDatabase db = myDbHelper.getReadableDatabase();
//SQLiteDatabase db = SQLiteDatabase.openDatabase("/data/data/com.example.abc2/databases/DB_BusData", null, 0);
Cursor c = db.rawQuery("SELECT * FROM Tbl_Driver", null);
startManagingCursor(c);
//create an array to specify which fields we want to display
String[] from = new String[]{"Driver_Name"};
//create an array of the display item we want to bind our data to
int[] to = new int[]{安卓.R.id.text1};
//create simple cursor adapter
SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, 安卓.R.layout.simple_spinner_item, c, from, to );
adapter.setDropDownViewResource( 安卓.R.layout.simple_spinner_dropdown_item );
//get reference to our spinner
Spinner s = (Spinner) findViewById( R.id.DriverSpin);
s.setAdapter(adapter);

db.close();
}

这是我如何将微调器与数据库绑定的代码，
但装订后的微调器会自动选择第一项，
我想让用户自己选择微调器，怎么办

Answer 1

SQLiteDatabase db = myDbHelper.getReadableDatabase();
//SQLiteDatabase db = SQLiteDatabase.openDatabase("/data/data/com.example.abc2/databases/DB_BusData", null, 0);
Cursor c = db.rawQuery("SELECT * FROM Tbl_Vehicle", null);
//=====Add Additional=====
MatrixCursor extras = new MatrixCursor(new String[] { "_id", "Plat_No" });
extras.addRow(new String[] { "-1","< Select Vehicle >" });
Cursor[] cursors = { extras, c };
c = new MergeCursor(cursors);
//===========================

只需将第一项添加为空白，或者我已添加“<；选择车辆>；”作为第一项

Answer 2

阅读本文档页：http://developer.android.com/reference/android/widget/AbsSpinner.html