Using SimpleCursorAdapter with Spinner?

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终归单人心
终归单人心 2021-01-13 12:24

I have a db with table \"mytable\" having 2 colums \"id\",\"sampletext\" I want to query distinct values of sampletext and feed to a Spinner using SimpleCursorAdapter.

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  • 2021-01-13 12:49

    Here's an example with raw query. Please note the first ID column returned by the query should be labeled as _id .

    MyDatabase.java:

    public class MyDatabase extends SQLiteAssetHelper {
         ...
        public Cursor getListNamesForDropDown() {
            SQLiteDatabase db = getReadableDatabase();
            String sql = "select ID _id, Name from MyTable order by Name ";
            Cursor c = db.rawQuery(sql, null);
            c.moveToFirst();
            return c;
        }
    

    MyActivity.java:

            @Override
            public void onCreate(Bundle savedInstanceState) {
    ....    
               Cursor cursorTest =  db.getListNamesForDropDown();
               android.widget.SimpleCursorAdapter  adapter = new android.widget.SimpleCursorAdapter(this, 
                       android.R.layout.simple_spinner_item,
                        cursorTest, 
                        new String[] {"Name"}, 
                        new int[] {android.R.id.text1}, 0);       
               adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
               spinnerTest.setAdapter(adapter);  
    
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  • 2021-01-13 13:00
    android.widget.SimpleCursorAdapter adapter = new android.widget.SimpleCursorAdapter(this,
                android.R.layout.simple_spinner_item,
                cursor,
                new String[] { DBOpenHelper.ACCOUNT_BANK },
                new int[] { android.R.id.text1 }, 0);
    
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    
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  • 2021-01-13 13:03
    what am i doing wrong
    

    you didnt read documentation ...

    there are two arrays of string with columns: first in used in query, second one in Adapter constructor(you used only one array for both)

    first one tells sqlite which columns should be taken to Cursor, second tells Adapter which ones should be showed/mapped to Views in single row...

    Next CursorAdapter needs Cursor with column named _id

    So now it's pretty obvious that we should do smthin like this:

    String[] queryCols=new String[]{"_id", "sampletext"};
    String[] adapterCols=new String[]{"sampletext"};
    int[] adapterRowViews=new int[]{android.R.id.text1};
    mycursor=sdb.query(true,"mytable", queryCols,null,null,null,null,null,null);
    sca=new SimpleCursorAdapter(this, android.R.layout.simple_spinner_item, mycursor, adapterCols, adapterRowViews,0);
    sca.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spn.setAdapter(sca);
    
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