Question

我刚开始学习Android编程。我有一个问题。如何创建自定义适配器以填充自定义ListView项目。

ListView商品代码：

item.xml

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <TextView
        android:id="@+id/titleView"
        ... />

    <TextView
        android:id="@+id/dateView"
        ... />

</RelativeLayout>

DataBase Helper：

    public class DataBase {
    public static final String DB_NAME = "appdb";
      public static final int DB_VERSION = 1;
      static final String TABLE_NAME = "passtab";
      final String LOG_TAG = "myLogs";
      public static final String COLUMN_ID = "_id";
      public static final String COLUMN_TITLE = "title_enter";
      public static final String COLUMN_LOGIN = "login_enter";
      public static final String COLUMN_PASSWORD = "password_enter";
      public static final String COLUMN_URL = "link_enter";
      public static final String COLUMN_COMMENT = "comment_enter";
      public static final String COLUMN_DATE = "date_enter";
      public String results;
      private DBHelper phdb;
      private static Context pcontext;
      private SQLiteDatabase pdb;

      private static final String DB_CREATE = 
         "create table " + TABLE_NAME + "(" +
              COLUMN_ID + " integer primary key autoincrement, " +
          COLUMN_TITLE + " VARCHAR(255), " +
          COLUMN_LOGIN + " VARCHAR(255), " +
          COLUMN_PASSWORD + " VARCHAR(255), " +
              COLUMN_URL + " VARCHAR(255), " +
              COLUMN_COMMENT + " text, " +
              COLUMN_DATE + " VARCHAR(255)" +
                ");";
public class DBHelper extends SQLiteOpenHelper{
       public DBHelper(Context context) {
               super(context, DB_NAME, null, DB_VERSION);
              }
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
      sqLiteDatabase.execSQL(DB_CREATE);
      }
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
      }     

}
public DataBase(Context c) {
    pcontext = c;
}
public DataBase open() throws SQLiteException {
    phdb = new DBHelper(pcontext);
    pdb = phdb.getWritableDatabase();
    return this;
}
public SQLiteDatabase getDatabase() {
    return pdb;
}
public void close() {
    pdb.close();
}
...
public List<String> getData() {
    String[] columns = new String[] { COLUMN_TITLE };
    Cursor c = pdb.query(TABLE_NAME, columns, null, null, null, null,
            null);

    List<String> results = new ArrayList<String>();
    int iCM = c.getColumnIndex(COLUMN_TITLE);

    for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
        results.add(c.getString(iCM));
    }
    return results;
}}

MainActivity：

 public class MainScreen extends FragmentActivity implements OnClickListener {

   ListView listViewMain;
   SQLiteDatabase db;
   DataBase DB;
   DBHelper dbH;
   Cursor cursor;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_screen);

...

listViewMain = (ListView) findViewById(R.id.listViewMain);

DBHelper dbc = new DBHelper(MainScreen.this);
dbc.open();

String[] cs = new String[] { DataBase.COLUMN_TITLE };

Log.d(LOG_TAG, cs.toString());

listViewMain.setAdapter(new MySimpleAdapter<String>(this,
android.R.layout.item, cs));

dbc.close();
}

    public class MySimpleAdapter extends SimpleAdapter {

public MySimpleAdapter(Context context,
List<? extends Map<String, ?>> data, int resource,
String[] from, int[] to) {
super(context, data, resource, from, to);
    }

如何编写适配器并将其用于ListView？

Answer 1

onCreate方法：

List<String> results = DBHelper.getData();
listViewMain = (ListView) findViewById(R.id.listViewMain);
ArrayAdapter adapter = new ArrayAdapter(this,
                android.R.layout.simple_list_item_1, results);
listViewMain.setListAdapter(adapter);

如何从DataBase填充自定义ListView项

1 个答案: