android - 想从数据库中搜索名称而不是数据库中的最后一个字段

Question

DBhelper 类

 public class DBHelper extends SQLiteOpenHelper{

    private static final String DB_NAME_TWO = "Loan_TWO.db";
    private static final int VERSION = 1;
    private SQLiteDatabase mDb;

    public DBHelper(Context context) {
        super(context, DB_NAME_TWO, null, VERSION);

    }

    @Override
    public void onCreate(SQLiteDatabase db) {


        //      db.execSQL("create table " + TABLE_COLLEGES + " ( "
        //              + COL_ID + " integer primary key autoincrement, "
        //              + COL_NAME + " text, "
        //              + COL_ADDRESS + " text);");


        db.execSQL("create table " + LOAN_TABLE + " ( "
                + ID + " integer primary key autoincrement, "
                + Name + " text,"
                + START_DATE + " text, "
                + END_DATE + " text, "
                + LOAN_AMOUNT + " integer, "
                + RATE_OF_INTEREST + " integer ," 
                + FINAL_AMOUNT + " integer) ;");



        db.execSQL("create table " + AMOUNT_TABLE_ONE + " ( "
                + AMOUNT_ID + " integer primary key autoincrement, "
                + ID + " integer, "
                + Name + " text, "
                + AMOUNT + " text, "
                + BALANCE_AMOUNT + " text, "
                + NEXT_DATE + " text, "
                + TODAYS_DATE + " text); ");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + LOAN_TABLE);
        db.execSQL("DROP TABLE IF EXISTS " + AMOUNT_TABLE_ONE);

        onCreate(db);
    }
}

SearchActivity 类

    public class SearchActivity extends Activity {

    private EditText Search_By_Name;
    private ArrayList<Personal_loan> array;
    private ArrayAdapter<Personal_loan> adapter;
    private ListView listView;
    SQLiteDatabase db;

    private DBHelper helper;
    Personal_loan p = new Personal_loan();

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_search);
        Search_By_Name = (EditText)findViewById(R.id.SearchName);

        array = new ArrayList<Personal_loan>();

        listView = (ListView) findViewById(R.id.listView1);
        adapter = new ArrayAdapter<Personal_loan>(this, android.R.layout.simple_list_item_1, array);
        listView.setAdapter(adapter);

    getData();

    }
    private void getData() {
        helper = new DBHelper(this);
        db = helper.getWritableDatabase();

        String columns[] = new String[] {ID,Name,START_DATE,END_DATE,LOAN_AMOUNT,RATE_OF_INTEREST,FINAL_AMOUNT};
        Cursor cursor = db.query( true, LOAN_TABLE, columns,"Name=?",new String[]{"Amit"}, null, null, null, null, null);

        if (!cursor.isAfterLast()) {
            cursor.moveToFirst();
            while (!cursor.isAfterLast()) {

                p = new Personal_loan();
                p.id = cursor.getInt(0);
                p.name = cursor.getString(1);
                p.sd = cursor.getString(2);
                p.ed = cursor.getString(3);
                p.la = cursor.getDouble(4);
                p.roi = cursor.getFloat(5);
                p.amt=cursor.getString(6);
                array.add(p);
                cursor.moveToNext();
                Search_By_Name.addTextChangedListener(new TextWatcher() {

                    public void onTextChanged(CharSequence s, int start, int before, int count) 
                    {
                        // TODO Auto-generated method stub

                    } 

                    public void beforeTextChanged(CharSequence s, int start, int count,
                            int after) 
                    {
                        // TODO Auto-generated method stub

                    }

                    public void afterTextChanged(Editable s) 
                    {

                        SearchActivity.this.adapter.getFilter().filter(s);
                    }
                });

            }

            cursor.close();
            db.close();
            adapter.notifyDataSetChanged();
        }       

    }


   public void onBackPressed() {
        // TODO Auto-generated method stub
        Intent i=new Intent(SearchActivity.this,FirstActivity.class);
        startActivity(i);
    }
}

个人贷款

public class Personal_loan {
    public int id;
    String name;
    String sd;
    String ed;
    Double la;
    float roi;
    String amt;


    @Override
    public String toString() {
        return " Person ID =" + id + "\n Name =" + name + "\n Start Date =" + sd
                + "\n End Date =" + ed + "\n Loan Amount =" + la + "\n Rate Of Interest =" + roi +"\n Loan Final Amount= "+ amt  ;
    }
}

我想从数据库中搜索名称并根据在 edittext 上键入的名称字段过滤列表，上面的代码按最后一个字段(即最终金额)搜索列表，但我想通过以下方式搜索它名称不是最终金额。

Answer 1

您真的应该尝试使用 SimpleCursorAdapter 而不是 ArrayAdapter 并将 adapter.swapCursor(cursor) 与具有正确的新游标一起使用在 afterTextChanged 上查询。

可选，推荐使用loaders对于任何数据库访问，这样您就不会减慢主 ui 线程。