setSelection on Spinner based on rowId

Question

Hi!

I have a Spinner View that's populated through a SimpleCursorAdapter. Based on the selection I need to save the rowid in the entry database (position won't work because things can be added and deleted from the Spinner Database). This I can do by using spinner.getAdapter().getItemId(pos) . But When I edit an entry I need to make the Spinner position selected that is associated with this rowid (currently).

spinner.setSelection(position) won't work because I have the rowid, I need a way to find the current position of the item in the current spinner based on the rowid in the database.

Answer 1

Had an idea when writing this, made a hashtable with rowid->pos when populating the spinner and then used that. Might help someone if they're searching.

Answer 2

If you want to set the selection of a Spinner thats backed by a CursorAdapter, you can loop through all the items in the Cursor and look for the one you want (assuming that the primary key in your table is named "_id"):

Spinner spinner = (Spinner) findViewById(R.id.spinner);
spinner.setAdapter(new SimpleCursorAdapter(...));

for (int i = 0; i < spinner.getCount(); i++) {
    Cursor value = (Cursor) spinner.getItemAtPosition(i);
    long id = value.getLong(value.getColumnIndex("_id");
    if (id == rowid) {
        spinner.setSelection(i);
    }
}

If you want to get the rowid of a selected item, you can do something similar:

Cursor cursor = (Cursor) spinner.getSelectedItem();
long rowid = cursor.getLong(cursor.getColumnIndex("_id"));

There might be a quicker way to do it, but that's always worked for me.

Answer 3

Why do it the hard way when you can do it the right way?

I refer to the manual:

http://d.android.com/reference/android/widget/AdapterView.OnItemSelectedListener.html#onItemSelected%28android.widget.AdapterView%3C?%3E,%20android.view.View,%20int,%20long%29

example code:

spinner.setOnItemSelectedListener(new OnItemSelectedListener() {
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id)
        {
            int index = spinner.getSelectedItemPosition();
            Toast.makeText(getBaseContext(), 
                "You have selected item : " + index + " which is row " + id, 
                Toast.LENGTH_SHORT).show();                
        }
        public void onNothingSelected(AdapterView<?> arg0) {}
    });

Thanks to evancharlton on #android-dev for this enlightment. :)