我正在尝试创建我的第一个安卓应用。我注意到如果数据库不存在,SQLiteOpenHelper.onCreate()
方法不会被调用来创建表。然而,即使我尝试进行调试,onCreate()
方法也没有起作用。
请查看下面的代码并给我任何建议。非常感谢您的帮助。
public class NameToPinyinActivity extends Activity {
DatabaseOpenHelper helper = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.nametopinyin);
Button searchButton = (Button) findViewById(R.id.search);
searchButton.setOnClickListener(new ButtonClickListener());
helper = new DatabaseOpenHelper(NameToPinyinActivity.this);
}
public class DatabaseOpenHelper extends SQLiteOpenHelper {
/** DB Name */
private static final String DB_NAME = "pinyin";
/** CREATE TABLE SQL */
private static final String CREATE_TABLE_SQL = "CREATE TABLE UNICODE_PINYIN"
+ "(ID INTEGER PRIMARY KEY AUTOINCREMENT, "
+ "UNICODE TEXT NOT NULL, PINYIN TEXT NOT NULL)";
public DatabaseOpenHelper(Context context) {
super(context, DB_NAME, null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.beginTransaction();
try {
db.execSQL(CREATE_TABLE_SQL);
db.setTransactionSuccessful();
} catch (Exception e) {
e.printStackTrace();
} finally {
db.endTransaction();
}
}