Question

所有！我是Android应用程序的新手。现在我有一些问题。我无法立即看到更改列表的结果（在我的ListFragment中更新listView之后）。例如，我调用了方法 addNewItem ，我没有在屏幕上看到任何更改。但如果我触摸ListFragment，我会看到所有的变化。

ListFragment：

public class PointsListFragment extends ListFragment {

    PlaceItemsAdapter adapter;

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        adapter = new PlaceItemsAdapter(
                getActivity(), R.layout.place_list_item,
                new ArrayList<PlaceItem>());
        setListAdapter(adapter);
        adapter.notifyDataSetChanged();
    }

   public void addNewItem(int id, String address) {
     adapter.items.add(new PlaceItem(id, address));
     adapter.notifyDataSetChanged();
    }


    private class PlaceItemsAdapter extends ArrayAdapter<PlaceItem> {

        private final int viewResourceId;
        final public ArrayList<PlaceItem> items;

        @Override
        public int getCount() {
            return items.size();
        }

        @Nullable
        @Override
        public PlaceItem getItem(int position) {
            return items.get(position);
        }

        public PlaceItemsAdapter(Context context, int viewResourceId, ArrayList<PlaceItem> items) {
            super(context, viewResourceId, items);
            this.items = items;
            this.viewResourceId = viewResourceId;

        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View v = convertView;
            if (v == null) {
                LayoutInflater vi = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                v = vi.inflate(viewResourceId, null);
            }
            PlaceItem placeItem = getItem(position);
            TextView placeIdTextView = (TextView) v.findViewById(R.id.placeId);
            placeIdTextView.setText(String.valueOf(placeItem.getId()));
            TextView placeAddressView = (TextView) v.findViewById(R.id.placeAddress);
            placeAddressView.setText(placeItem.getAddress());
            if (selectedValue == position) {
                v.setBackgroundResource(R.drawable.active_item);
            }
            return v;
        }

    }
}

我的活动xml

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"[enter image description here][1]
        android:padding="2dp">
        >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:background="@color/forBorder"
            android:orientation="horizontal">

            <Spinner
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:id="@+id/spinner"
                android:layout_weight="1" />

            <TextView
                android:text="проложить маршрут"
                android:textColor="@android:color/white"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" />

            <ImageButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@android:drawable/ic_media_ff" />

        </LinearLayout>

        <fragment
            class="com.restfulrobot.cdcapplication.PointsListFragment"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/list_frag" />
    </LinearLayout>

图片示例 ListView Problem

Answer 1

谢谢你，好！我找到了答案！我从另一个类调用了方法（没有Activity或Fragment）。现在我也从另一个类调用方法，但我通过Handler来做。它现在真的很好用！这样的事情：

 Message msg = mainActivityHandler.obtainMessage(MainActivity.NEW_MESSAGE, someObjectToAdd);
 mainActivityHandler.sendMessage(msg);

ListFragment不显示当前时间的更改

1 个答案: