将游标数据放入数组中

Question

在Android中是新手,我在处理以下内容时遇到问题:

public String[] getContacts(){
    Cursor cursor = getReadableDatabase().rawQuery("SELECT name FROM contacts", null);
    String [] names = {""};
    for(int i = 0; i < cursor.getCount(); i ++){
            names[i] = cursor.getString(i);
    }
    cursor.close();
    return names;
}

以下给出了以下错误:

09-18 10:07:38.616: E/AndroidRuntime(28165): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.sqllitetrial/com.example.sqllitetrial.InsideDB}: android.database.CursorIndexOutOfBoundsException: Index -1 requested, with a size of 5

我试图将光标内的数据提取到一个数组.有人可以帮我实现.

Answer 1

names.add(cursor.getString(i));

"i"不是游标行索引,而是列索引.游标已定位到特定行.如果需要重新定位光标.使用cursor.move或moveToXXXX(参见文档).

对于getString/Int/Long等,您只需要告诉光标您想要哪一列.如果您不知道可以使用的columnIndex cursor.getColumnIndex("yourColumnName").

你的循环应该如下所示:

public String[] getContacts(){
    Cursor cursor = getReadableDatabase().rawQuery("SELECT name FROM contacts", null);
    cursor.moveToFirst();
    ArrayList<String> names = new ArrayList<String>();
    while(!cursor.isAfterLast()) {
        names.add(cursor.getString(cursor.getColumnIndex("name")));
        cursor.moveToNext();
    }
    cursor.close();
    return names.toArray(new String[names.size()]);
}

Answer 2

我希望它对你有用.

 public static ArrayList<ModelAgents> SelectAll(DbHelper dbaConnection) {
            ArrayList<ModelAgents> Agents_aList = new ArrayList<ModelAgents>();

            SQLiteDatabase sqldb = dbaConnection.openDataBase();
            Cursor cursor = sqldb.rawQuery("SELECT * FROM Agents", null);
            if (cursor != null)// If Cursordepot is null then do
                                // nothing
            {
                if (cursor.moveToFirst()) {


                    do {
                        // Set agents information in model.
                        ModelAgents Agents = new ModelAgents();
                        Agents.setID(cursor.getInt(cursor
                                .getColumnIndex(TblAgents.ID)));
                        Agents.setCode(cursor.getString(cursor
                                .getColumnIndex(TblAgents.CODE)));
                        Agents.setName(cursor.getString(cursor
                                .getColumnIndex(TblAgents.NAME)));

                        Agents_aList.add(Agents);
                    } while (cursor.moveToNext());
                }
                cursor.close();
            }

            sqldb.close();

            return Agents_aList;

        }