使用游标实现 setMultiChoiceItems 时,必须指定 isCheckedColumn。
正如其他网站所阐述的那样,问题是当用户从列表中选择一个项目时,复选框不会更新。有些人建议每次用户选择一个项目时更新 Sqlite 表,但这在我的应用程序中不起作用。这是我想出的解决方案。
这就是我想出的:
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
int myDialogChoice = getArguments().getInt("whichDialog");
mSelectedItems = new ArrayList(); // Where we track the selected items
mCurrentFavoritesSelection = new ArrayList();
myDataBaseAdapter = new AthleteDbAdapter(getActivity());
// int myAthleteId;
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
switch(myDialogChoice) {
case Select_From_Favorites:
myCursorFromSqLite = myDataBaseAdapter.fetchAllFavorites(getActivity());
// You need a Primative Boolean Array to specify which items were selected last time.
boolean[] booleanPrimativeArray = new boolean[myCursorFromSqLite.getCount()];
final ArrayList mArrayListOfIDs = new ArrayList();
ArrayList<Boolean> myBooleanList = new ArrayList<Boolean>();
// This array will be the choices that appear in the Dialog.
ArrayList<String> mArrayListOfNames = new ArrayList<String>();
myCursorFromSqLite.moveToFirst();
/* Populate Arrays
*
*/
int iCount = 0;
while(!myCursorFromSqLite.isAfterLast()) {
// put _id's from SqLite data into an array.
mArrayListOfIDs.add(Integer.valueOf(
myCursorFromSqLite.getString(myCursorFromSqLite.getColumnIndex(KEY_ROWID))));
// put series of booleans into Primative Array depending upon whether user selected them last time.
if(Integer.valueOf(myCursorFromSqLite.getString(myCursorFromSqLite.getColumnIndex("checked"))) == 1){
booleanPrimativeArray[iCount] = true;
mSelectedItems.add(
Integer.valueOf(myCursorFromSqLite.getString(myCursorFromSqLite.getColumnIndex(KEY_ROWID)))
);
// I kept track of what selections from last time were.
mCurrentFavoritesSelection.add(
Integer.valueOf(myCursorFromSqLite.getString(myCursorFromSqLite.getColumnIndex(KEY_ROWID)))
);
} else booleanPrimativeArray[iCount] = false;
iCount++;
mArrayListOfNames.add(myCursorFromSqLite.getString(myCursorFromSqLite.getColumnIndex("fullName")));
myCursorFromSqLite.moveToNext();
}
// Change the ArrayList of names to a Char Sequence
CharSequence[] charSeqOfNames = mArrayListOfNames.toArray(new CharSequence[mArrayListOfNames.size()]);
try{
myCursorFromSqLite.close();
} catch (Throwable t) {
Log.e(APP_TAG,"Error closing myCursorFromSqLite Cursor " + t);
}
builder.setTitle(R.string.pick_athletes)
.setMultiChoiceItems(charSeqOfNames, booleanPrimativeArray,
new DialogInterface.OnMultiChoiceClickListener() {
@Override
public void onClick(DialogInterface dialog, int which,
boolean isChecked) {
if (isChecked) {
// If the user checked the item, build an array containing the selected items _id's.
mSelectedItems.add((Integer) mArrayListOfIDs.get(which));
} else if (mSelectedItems.contains((Integer) mArrayListOfIDs.get(which))) {
// Else, if the user changes his mind and de-selects an item, remove it
mSelectedItems.remove((Integer) mArrayListOfIDs.get(which));
}
}
})
// Set the action buttons
.setPositiveButton(R.string.pullathletesbutton, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int id) {
// User clicked OK, so save the mSelectedItems results somewhere
// or return them to the component that opened the dialog
Log.d(APP_TAG,"Call something");
mListener.onDialogPositiveClick(PickListDialog.this, mSelectedItems, mCurrentFavoritesSelection);
}
})
.setNegativeButton(R.string.cancelbutton, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int id) {
}
});
这运作良好。用户可以在不影响底层数据库的情况下改变主意,并且复选标记会正确更新。一旦用户完成了他的选择,他点击“肯定”按钮并更新数据库。