0
我一直在玩SQLite一點點，我正在研究如何創建選項卡。我使用http://developer.android.com/resources/tutorials/notepad/index.html中的記事本示例，並使用3個選項卡處理它。問題是，當我保存值時，sqlite無法獲取edittext中的內容。當我嘗試在我的歷史記錄選項卡中查看它們時，它只顯示我在製作選項卡之前保存的舊值。當我點擊我在製作標籤之前保存的內容時，它會將我帶到活動中，而沒有頂部的標籤，然後我實際上可以更新它。所以，當選項卡位於頂部時，它似乎無法獲取edittext中的內容，但是可以在它自己的佈局上得到它。SQLite不與Tabhost一起工作 - Android
創建選項卡時是否有任何缺少的東西？
這是我在第一個選項卡至今：
private EditText etVelocity;
private EditText etType;
private Long mRowId;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.new_entry);
etVelocity = (EditText) findViewById(R.id.etVelocity);
etType = (EditText) findViewById(R.id.etType);
Button bSave = (Button) findViewById(R.id.btnSave);
Button bReset = (Button) findViewById(R.id.btnReset);
mRowId = null;
Bundle extras = getIntent().getExtras();
if (extras != null)
{
String title = extras.getString(DbAdapter.KEY_TITLE);
String body = extras.getString(DbAdapter.KEY_BODY);
mRowId = extras.getLong(DbAdapter.KEY_ROWID);
if (title != null)
{
etVelocity.setText(title);
}
if (body != null)
{
etType.setText(body);
}
}
bSave.setOnClickListener(new View.OnClickListener()
{
public void onClick(View view)
{
Bundle bundle = new Bundle();
bundle.putString(DbAdapter.KEY_TITLE, etVelocity.getText().toString());
bundle.putString(DbAdapter.KEY_BODY, etType.getText().toString());
if (mRowId != null)
{
bundle.putLong(DbAdapter.KEY_ROWID, mRowId);
}
Intent mIntent = new Intent();
mIntent.putExtras(bundle);
setResult(RESULT_OK, mIntent);
finish();
}
});
bReset.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
resetDisplay();
}
});
}
public void resetDisplay()
{
etVelocity.setText("");
etType.setText("");
}
歷史記錄選項卡顯示的條目：
private static final int ACTIVITY_CREATE=0;
private static final int ACTIVITY_EDIT=1;
private static final int INSERT_ID = Menu.FIRST;
private static final int DELETE_ID = Menu.FIRST + 1;
private DbAdapter mDbHelper;
private Cursor mNotesCursor;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.notes_list);
mDbHelper = new DbAdapter(this);
mDbHelper.open();
fillData();
registerForContextMenu(getListView());
}
private void fillData() {
// Get all of the rows from the database and create the item list
mNotesCursor = mDbHelper.fetchAllNotes();
startManagingCursor(mNotesCursor);
// Create an array to specify the fields we want to display in the list (only TITLE)
String[] from = new String[]{DbAdapter.KEY_TITLE};
// and an array of the fields we want to bind those fields to (in this case just text1)
int[] to = new int[]{R.id.text1};
// Now create a simple cursor adapter and set it to display
SimpleCursorAdapter notes =
new SimpleCursorAdapter(this, R.layout.notes_row, mNotesCursor, from, to);
setListAdapter(notes);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
menu.add(0, INSERT_ID, 0, R.string.menu_insert);
return true;
}
@Override
public boolean onMenuItemSelected(int featureId, MenuItem item) {
switch(item.getItemId()) {
case INSERT_ID:
createNote();
return true;
}
return super.onMenuItemSelected(featureId, item);
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
menu.add(0, DELETE_ID, 0, R.string.menu_delete);
}
@Override
public boolean onContextItemSelected(MenuItem item) {
switch(item.getItemId()) {
case DELETE_ID:
AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
mDbHelper.deleteNote(info.id);
fillData();
return true;
}
return super.onContextItemSelected(item);
}
private void createNote() {
Intent i = new Intent(this, Tab1.class);
startActivityForResult(i, ACTIVITY_CREATE);
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
Cursor c = mNotesCursor;
c.moveToPosition(position);
Intent i = new Intent(this, Tab1.class);
i.putExtra(DbAdapter.KEY_ROWID, id);
i.putExtra(DbAdapter.KEY_TITLE, c.getString(
c.getColumnIndexOrThrow(DbAdapter.KEY_TITLE)));
i.putExtra(DbAdapter.KEY_BODY, c.getString(
c.getColumnIndexOrThrow(DbAdapter.KEY_BODY)));
startActivityForResult(i, ACTIVITY_EDIT);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
super.onActivityResult(requestCode, resultCode, intent);
Bundle extras = intent.getExtras();
switch(requestCode) {
case ACTIVITY_CREATE:
String title = extras.getString(DbAdapter.KEY_TITLE);
String body = extras.getString(DbAdapter.KEY_BODY);
mDbHelper.createNote(title, body);
fillData();
break;
case ACTIVITY_EDIT:
Long rowId = extras.getLong(DbAdapter.KEY_ROWID);
if (rowId != null) {
String editTitle = extras.getString(DbAdapter.KEY_TITLE);
String editBody = extras.getString(DbAdapter.KEY_BODY);
mDbHelper.updateNote(rowId, editTitle, editBody);
}
fillData();
break;
}
}
將對DBAdapter類：
public static final String KEY_TITLE = "title";
public static final String KEY_BODY = "body";
public static final String KEY_ROWID = "_id";
private static final String TAG = "NotesDbAdapter";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
private static final String DATABASE_CREATE =
"create table notes (_id integer primary key autoincrement, "
+ "title text not null, body text not null);";
private static final String DATABASE_NAME = "data";
private static final String DATABASE_TABLE = "notes";
private static final int DATABASE_VERSION = 2;
private final Context mCtx;
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS notes");
onCreate(db);
}
}
public DbAdapter(Context ctx) {
this.mCtx = ctx;
}
public DbAdapter open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close() {
mDbHelper.close();
}
public long createNote(String title, String body) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_TITLE, title);
initialValues.put(KEY_BODY, body);
return mDb.insert(DATABASE_TABLE, null, initialValues);
}
public boolean deleteNote(long rowId) {
return mDb.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
public Cursor fetchAllNotes() {
return mDb.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_TITLE,
KEY_BODY}, null, null, null, null, null);
}
public Cursor fetchNote(long rowId) throws SQLException {
Cursor mCursor = mDb.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,
KEY_TITLE, KEY_BODY}, KEY_ROWID + "=" + rowId, null,
null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
public boolean updateNote(long rowId, String title, String body) {
ContentValues args = new ContentValues();
args.put(KEY_TITLE, title);
args.put(KEY_BODY, body);
return mDb.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
}
定義「無法正常工作」 – Selvin
當選項卡位於頂部且下方有活動時，它無法保存edittext字段中的值，然後將其顯示在歷史記錄選項卡中。 – user990230
那也是太多的代碼！嘗試縮小它！ – gideon