Nick,
- Since list item views get recycled, you've got to have something that
maintains item state (checked / unchecked) - besides the checkboxes in
your list, since those are part of recycled item layouts.
- To change data in the database, use the usual database update methods.
Other than constantly opening and closing the database, your code looks ok.
- To refresh the list, call adapter.notifyDataSetChanged(). This causes
the list view to rebuild its item views, calling your getView(), which
sets checkbox state according to values in the database.
-- Kostya
29.01.2011 23:58, Nick пишет:
I'm using SimpleCursorAdapter just because I store data in the
database.
And you suggested to use standard layout what isn't suitable for me.
On 29 янв, 20:46, Robin Talwar<[email protected]> wrote:
Its better to use
ArrayAdapter<String> adapter=new
ArrayAdapter<String>(playlist_new.this,android.R.layout.simple_list_item_mu
ltiple_choice,song_name);
lv.setAdapter(adapter);
lv.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
On Sat, Jan 29, 2011 at 10:51 PM, Nick<[email protected]> wrote:
Hi! I have ONE annoying problem with SimpleCursorAdapter. My programm
has list view and ListActivity. Each row has it's own layout:
<TableLayout xmlns:android="http://schemas.android.com/apk/res/
android"
android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:orientation="horizontal" android:weightSum="1.0">
<TableRow>
<TextView android:id="@+id/task_time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="24sp" android:text="Time">
</TextView>
<LinearLayout android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="fill_parent">
<TextView android:id="@+id/task_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp" android:text="Name">
</TextView>
<TextView android:id="@+id/task_categoty"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Category" android:textSize="12sp">
</TextView>
</LinearLayout>
<TextView android:id="@+id/task_state"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="State" android:textSize="12sp">
</TextView>
<CheckBox android:id="@+id/task_enabled"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:focusable="false">
</CheckBox>
</TableRow>
Tasks are stored in SQLite database. I have DAO object (singleton) to
access the database. TaskDao:
public void updateEnabled(int id, boolean enabled){
SQLiteDatabase db = dbHelper.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(ENABLED_COLUMN, enabled==true?1:0);
Log.i(TAG, "update to " + cv.get(ENABLED_COLUMN) );
try{
db.beginTransaction();
db.update(TASK_TABLE, cv, ID_COLUMN+"=?", new String[]{id
+""});
db.setTransactionSuccessful();
} catch (SQLException e) {
Log.i(TAG, "edit task failed!");
} finally {
db.endTransaction();
if (db != null)
db.close();
}
}
and the Cursor method for ListActivity:
public Cursor getTasks(){
SQLiteDatabase db = dbHelper.getReadableDatabase();
return db.query(TASK_TABLE, COLUMNS, null, null, null, null,
NAME_COLUMN);
}
I extended SimpleCursorAdapter (TaskDbAdapter) like this:
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
if(convertView==null){
convertView = inflater.inflate(R.layout.task_list_row, null);
}
Cursor c = getCursor();
c.moveToPosition(position);
Log.i(TAG, "getView " + position + " = " + c.getInt(enabledIdx));
enabled.setTag(c.getInt(c.getColumnIndex(BaseColumns._ID)));
enabled.setChecked(c.getInt(enabledIdx)>0?true:false);
enabled.setOnClickListener(this);
return convertView;
}
@Override
public void onClick(View v) {
CheckBox box = (CheckBox) v;
Integer id = (Integer)box.getTag();
TaskDao.getInstance(context).updateEnabled(id.intValue(),
box.isChecked());
}
And at last I use all the above stuff in my main ListActivity
private void refreshList(){
c = TaskDao.getInstance(this).getTasks();
startManagingCursor(c);
adapter = new TaskDbAdapter(this, R.layout.task_list_row, c, new
String[]{TaskDao.ENABLED_COLUMN}, new int[]{R.id.task_enabled});
setListAdapter(adapter);
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.task);
getListView().setItemsCanFocus(false);
getListView().setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
getListView().setVerticalScrollBarEnabled(true);
registerForContextMenu(getListView());
getListView().setOnCreateContextMenuListener(this);
refreshList();
}
@Override
protected void onResume() {
super.onResume();
refreshList();
}
@Override
protected void onPause() {
super.onPause();
}
Everything works fine. But CheckBoxes loose their states. For instance
I check my first column and scroll the list down. In my trace before
press I have:
getView 0 = 0
getView 2 = 0
getView 3 = 0
then
uptate to 1
and then (when I scroll up to the first element)
getView 0 = 0
getView 2 = 0
getView 3 = 0
I tried to make getCursor().requery(); in my TaskDbAdapter onClick
method. But then I saw no items in the list! And exception because of
cursor management(connection was closed by android). When I write
startManagingCursor(c); in refreshList() method then check and uncheck
methods don't work. Please, Help!
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Kostya Vasilyev -- WiFi Manager + pretty widget -- http://kmansoft.wordpress.com
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