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从数据库内容填充微调器(SQLite)

spinner sqlite android java

Gabriel · 技术社区 · 7 年前

如何从数据库(SQLite)填充微调器内容

我已经有了这个表,有一个函数可以像这样获取ArrayList:

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;
}

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);

当我运行它时,它加载如下字符串:“schema。SetcardCategory@22293c98“还有许多其他类似的价值观。

如何填充微调器以将名称字段显示为标签,将id字段显示为我们获取并保存到DB中的值?

2 回复 | 直到 7 年前

Manoj kumar 7 年前

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

在pojo类中这样做,这样当对象在适配器中使用to string方法加载数据时,它将返回一个值

J.R 7 年前

解决方案1 覆盖SetcardCategory类中的toString方法

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

解决方案2 如果您只想显示名称,只需从DB中选择名称即可

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;
    }

并将阵列适配器创建为

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);