【发布时间】:2015-09-07 17:54:41
【问题描述】:
我的 android 应用程序有奇怪的问题。我有一些数据,我将这些数据保存在 SQLite 数据库中。在这个片段中,我尝试使用SimpleCursorAdapter从表中读取我的数据
public class LogFragment extends Fragment{
private static SQLiteDatabase db;
private static SQLiteOpenHelper helper;
private static Context context;
private static ListView listView;
private static String senderOrReceiver;
private static SimpleCursorAdapter adapter;
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
context = getActivity();
adapter = new SimpleCursorAdapter(context, R.layout.log_message, null,
new String[]{Constants.COMMAND, Constants.VALUE, Constants.TIME_STAMP, Constants.MESSAGE_ID, Constants.SESSION_ID, Constants.PARAMS},
new int[]{R.id.command, R.id.value, R.id.time_stamp, R.id.message_id, R.id.session_id, R.id.params}, 0);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_log, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
listView = (ListView) view.findViewById(R.id.listView);
}
@Override
public void onDestroy() {
super.onDestroyView();
if(db != null){
db.close();
}
}
public static void readFromDatabase(String sender){
senderOrReceiver = sender;
new DatabaseTalker().execute();
}
private static class DatabaseTalker extends AsyncTask <Void, Void, Cursor>{
@Override
protected Cursor doInBackground(Void... params) {
helper = new Database(context);
db = helper.getReadableDatabase();
return db.query(Constants.TABLE_NAME, null, null, null, null, null, null);
}
@Override
protected void onPostExecute(Cursor cursor) {
super.onPostExecute(cursor);
adapter.changeCursor(cursor);
listView.setAdapter(adapter);
}
}
}
这就是我在 ListView 中得到的内容。我有六个字段(Command、Value、Time Stamp、MessageID、SessionID、Params),你可以看到只有一个字段被填写(例如)Command: On, Value: , Time Stamp: , MessageID: , SessionID: , Params: . 等等......为什么我会得到这个结果?
编辑:
我如何将数据写入数据库
public void addInfo(Information info){
SQLiteDatabase db = this.getWritableDatabase();
addToTable(db, Constants.COMMAND, info.getCommand());
addToTable(db, Constants.VALUE, info.getValue());
addToTable(db, Constants.TIME_STAMP, info.getTimeStamp());
addToTable(db, Constants.MESSAGE_ID, info.getMessageID());
addToTable(db, Constants.SESSION_ID, info.getSessionID());
addToTable(db, Constants.PARAMS, info.getParams());
db.close();
}
private static void addToTable(SQLiteDatabase db, final String TAG, String value){
ContentValues values = new ContentValues();
values.put(TAG, value);
db.insert(Constants.TABLE_NAME, null, values);
}
【问题讨论】:
-
你是如何将数据写入数据库的?
-
@laalto 我刚刚编辑了我的帖子。
标签: android sqlite simplecursoradapter