从数据库内容填充微调器（SQLite）

Question

How can I populate a spinner content from database (SQLite)

I have POJO: categories, contain id and name, I have the table already, with a function to get the ArrayList like this:

public List<SetcardCategory> getAllSetcardCategory()
{
    List<SetcardCategory> setcardCategories = new ArrayList<SetcardCategory>();
    String selectQuery = "SELECT  * FROM " + TABLE_SETCARD_CATEGORIES;

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor c = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (c.moveToFirst()) {
        do {
            SetcardCategory setcardCategory = new SetcardCategory();
            setcardCategory.setId(c.getInt((c.getColumnIndex("id"))));
            setcardCategory.setName(c.getString(c.getColumnIndex("name")));

            // adding to tags list
            setcardCategories.add(setcardCategory);
        } while (c.moveToNext());
    }
    return setcardCategories;
}

Then on Activity I call it like this:

List<SetcardCategory> setcardCategories = db.getAllSetcardCategory();
    ArrayAdapter<SetcardCategory> arrayAdapter = new ArrayAdapter<SetcardCategory>(
            this, android.R.layout.simple_spinner_item, setcardCategories);
    arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    Spinner sItems = (Spinner) findViewById(R.id.setcardCategory);
    sItems.setAdapter(arrayAdapter);

when I run it, it loads string like this: "schema.SetcardCategory@22293c98" and many others values similar to that.

How can I populate the spinner to show the name field as a label, and id field as the value that we fetch to save into DB?

Answer 1

class Pojo{
 private String name;
  @Override
    public String toString() {
        return name;
    }
}

do it like this in the pojo class, so this will return a value for the object when it uses the to string method in the adapter, to load the data

Answer 2

Solution 1 Overide the toString method in your SetcardCategory class

class SetcardCategory {
...
...
@Override
    public String toString() {
        return this.name;
    }
}

Solution 2 If you just want to show the name, Just pick name only from DB

public List<String> getAllSetcardCategory()
    {
        List<String> setcardCategories = new ArrayList<String>();
        String selectQuery = "SELECT  * FROM " + TABLE_SETCARD_CATEGORIES;

        SQLiteDatabase db = this.getReadableDatabase();
        Cursor c = db.rawQuery(selectQuery, null);

        // looping through all rows and adding to list
        if (c.moveToFirst()) {
            do {
                // adding to tags list
                setcardCategories.add(c.getString(c.getColumnIndex("name")));
            } while (c.moveToNext());
        }
        return setcardCategories;
    }

And create Array Adapter as

List<String> setcardCategories = db.getAllSetcardCategory();
    ArrayAdapter<SetcardCategory> arrayAdapter = new ArrayAdapter<SetcardCategory>(
            this, android.R.layout.simple_spinner_item, setcardCategories);
    arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);