I was looking for an alternative to a spinner, since the first item is always selected (which causes me issues), and I found some examples for using an AlertDialog with a list instead.
I am having two problems:
The list is displaying and is formatted ok, but there are no values in it. I know the query is returning, and the cursor/adapter has the data in it.
This may be a symptom of #1 - but when I select a blank row, the Cursor cursor2 = (Cursor) ((AdapterView) dialog).getItemAtPosition(which); statement causes a crash (it's a ClassCastException).
I had similar code previously which set the adapter to a spinner object, and the data was displaying fine.
I don't think the adapter is getting set correctly, and I have been unable to come up with a solution thus far.
Any thoughts?
Thanks!
btnDenomination.setOnClickListener(new View.OnClickListener()
{
public void onClick(View w)
{
Cursor cursor = coinDB.myDataBase.rawQuery("select _id, denomination_desc from denomination", null); // must select the _id field, but no need to use it
startManagingCursor(cursor); // required in order to use the cursor in
String[] from = new String[] {"denomination_desc" }; // This is the database column name I want to display in the spinner
int[] to = new int[] { R.id.tvDBViewRow }; // This is the TextView object in the spinner
cursor.moveToFirst();
SimpleCursorAdapter adapterDenomination = new SimpleCursorAdapter(CoinsScreen.this,
android.R.layout.simple_spinner_item, cursor, from, to );
adapterDenomination.setDropDownViewResource(R.layout.db_view_row);
new AlertDialog.Builder(CoinsScreen.this)
.setTitle("Select Denomination")
.setAdapter(adapterDenomination, new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int which)
{
Cursor cursor2 = (Cursor) ((AdapterView<?>) dialog).getItemAtPosition(which);
strDenomination_id = cursor2.getString(0); // Gets column 1 in a zero based index, the first column is the PKID. this could
// be avoided by using a select AS statement.
Log.d("Item Selected", strDenomination_id );
TextView txtDenomination = (TextView) findViewById(R.id.textDenomination);
txtDenomination.setText(cursor2.getString(1));
dialog.dismiss();
}
}).create().show();
}
});
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="@+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<TextView android:text=""
android:id="@+id/tvDBViewRow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#FF0000" />
</LinearLayout>
Are you sure R.id.tvDBViewRow is the id of the TextView in the layout android.R.layout.simple_spinner_item ? From this, the TextView's id should be android.R.id.text1.
So new answer for the second issue :)
I think you should reuse the initial cursor instead of trying to get a new one... Can you try to do :
adapterDenomination.moveToPosition(which);
strDenomination_id = adapterDenomination.getString(0);
in the onClick() ?
来源:https://stackoverflow.com/questions/8433923/android-simplecursoradapter-results-not-displaying-in-alertdialog