如何將數據從SQLite數據庫添加到ArrayList（Android）

Question

我是Android的新手，正在制作待辦事項列表應用程序。 我有一個包含一列任務的數據庫。 如何將這些任務放到ArrayList中並顯示它？

helper = new TaskDBHelper(MainActivity.this);
        SQLiteDatabase db = helper.getReadableDatabase();
        Cursor cursor = db.query(TaskContract.TABLE, new String[]{TaskContract.Columns._ID,TaskContract.Columns.TASK}, null, null, null, null, null);

        arrayListToDo = new ArrayList<String>();

arrayAdapterToDo = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, arrayListToDo);

        ListView listViewToDo = (ListView) findViewById(R.id.listViewToDo);
        listViewToDo.setAdapter(arrayAdapterToDo);

Answer 1

試試這個代碼

while (cursor.moveToNext()) {

arrayListToDo.add(cursor.getString(cursor.getColumnIndex("Your column name")));
}

Answer 2

您可以在數組列表中獲取數據：

 ArrayList<String> arrayListToDo= new ArrayList<String>(); //your query will returns cursor if (cursor.moveToFirst()) { do { arrayListToDo.add(get you string from cursor); } while (cursor.moveToNext()); } 

現在將這個列表添加到您的適配器中。

Answer 3

從數據庫獲取列表數據，這只是概述

     ArrayList<String> data = databaseObject.GetList();
ListView listViewToDo = (ListView) findViewById(R.id.listViewToDo);
arrayAdapterToDo = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, data);
listViewToDo.setAdapter(arrayAdapterToDo);


      ArrayList<String> GetList()
    {
        ArrayList<String> arrayListtemp= new ArrayList<String>();
        SQLiteDatabase db = helper.getReadableDatabase();
        Cursor cursor = db.query(TaskContract.TABLE, new String[]{TaskContract.Columns._ID,TaskContract.Columns.TASK}, null, null, null, null, null);
        if (cursor.moveToFirst()) {
            do {
                arrayListtemp.add("");// added your table value from database
            } while (cursor.moveToNext());
        }
        return arrayListtemp;
    }