Question

我实施了CursorAdapter但在数据库中添加新记录时无法更新listview。

我的代码是

获取数据库数据的光标。

// TodoDatabaseHandler is a SQLiteOpenHelper class connecting to SQLite
TodoDatabaseHandlerhandler = new TodoDatabaseHandler(this);
// Get access to the underlying writeable database
SQLiteDatabase db = handler.getWritableDatabase();
// Query for items from the database and get a cursor back
Cursor todoCursor = db.rawQuery("SELECT  * FROM todo_items", null);

ListView初始化。

// Find ListView to populate
ListView lvItems = (ListView) findViewById(R.id.lvItems);
// Setup cursor adapter using cursor from last step
TodoCursorAdapter todoAdapter = new TodoCursorAdapter(this, todoCursor);
// Attach cursor adapter to the ListView 
lvItems.setAdapter(todoAdapter);

CursorAdapter类。

public class TodoCursorAdapter extends CursorAdapter {
  public TodoCursorAdapter(Context context, Cursor cursor, int flags) {
      super(context, cursor, 0);
  }

  // The newView method is used to inflate a new view and return it, 
  // you don't bind any data to the view at this point. 
  @Override
  public View newView(Context context, Cursor cursor, ViewGroup parent) {
      return LayoutInflater.from(context).inflate(R.layout.item_todo, parent, false);
  }

  // The bindView method is used to bind all data to a given view
  // such as setting the text on a TextView. 
  @Override
  public void bindView(View view, Context context, Cursor cursor) {
      // Find fields to populate in inflated template
      TextView tvBody = (TextView) view.findViewById(R.id.tvBody);
      TextView tvPriority = (TextView) view.findViewById(R.id.tvPriority);
      // Extract properties from cursor
      String body = cursor.getString(cursor.getColumnIndexOrThrow("body"));
      int priority = cursor.getInt(cursor.getColumnIndexOrThrow("priority"));
      // Populate fields with extracted properties
      tvBody.setText(body);
      tvPriority.setText(String.valueOf(priority));
  }
}

Answer 1

试试这个，

public void updateList(){
    // Get access to the underlying writeable database
    SQLiteDatabase db = handler.getWritableDatabase();
    // Query for items from the database and get a cursor back
    Cursor newCursor= db.rawQuery("SELECT  * FROM todo_items", null);

    // here updated records are added in your cursor
    todoAdapter.changeCursor(newCursor);

}

通过这个，您将获得更新的结果。

游标适配器Android

1 个答案: