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在使用领域删除ListView的数据后,如何在scrollView中刷新ListView?

scrollview realm listview android

Deepa · 技术社区 · 7 年前

我正在使用ScrollView中的ListView。每当我对ListView数据执行删除操作时,都会删除数据,但问题是在删除数据之后,不幸的是,应用程序已经停止。我使用领域来存储数据和删除领域中的数据。这是我的密码。

listViewSearchCity.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
            PostUserItinerary item = (PostUserItinerary) listViewSearchCity.getItemAtPosition(i);
            view.setBackgroundColor(Color.parseColor("#a9a9a9"));
            // change1();
            h=item.getSearchCity();
            onclick();
            // onitemclick();

        }
    });
public void onclick()
{

    imgDelete.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            //PostItinerarySearchCityAdapter adapter = new PostItinerarySearchCityAdapter(PostUserItineraryActivity.this,helper.justRefresh());
            String type =h ;
            final RealmResults<PostUserItinerary> students = realm.where(PostUserItinerary.class).findAll();

            PostUserItinerary postUserItinerary = students.where().equalTo("searchCity", type).findFirst();

            if (postUserItinerary != null) {

                if (!realm.isInTransaction()) {
                    realm.beginTransaction();
                }

                postUserItinerary.deleteFromRealm();
                realm.commitTransaction();
                adapter.notifyDataSetChanged();
               // listViewSearchCity.setAdapter(adapter);

            }
        }
        //final int position2 = holder.getAdapterPosition();



    });

}

这是我的日志秀。

10-17 10:51:09.717 6586-6586/com。西提兹。xitizmobile E/AndroidRuntime:致命异常:main Java语言lang.NullPointerException 在com。西提兹。xitizmobile。postseritineraryactivity$7。onClick(postseritineraryactivity.java:327) 在安卓。看法看法performClick(视图.java:4444) 在安卓。看法查看$PerformClick。运行(View.java:18440) 在安卓。操作系统。处理程序。handleCallback(Handler.java:733) 在安卓。操作系统。处理程序。dispatchMessage(Handler.java:95) 在安卓。操作系统。活套。循环(Looper.java:136) 在安卓。应用程序。活动线程。main(ActivityThread.java:5052) 在java。郎。反思。方法invokenactive(本机方法) 在java。郎。反思。方法调用(方法.java:515) 在com。安卓内部的操作系统。ZygoteInit$MethodandArgscaler。运行(ZygoteInit.java:796) 在com。安卓内部的操作系统。合子岩。main(ZygoteInit.java:612) 在dalvik。系统国家艺术。主(本机方法)

1 回复 | 直到 7 年前

EpicPandaForce 7 年前

做这件事的简单方法是 PostItinerarySearchCityAdapter extends RealmBaseAdapter<PostUserItinerary> ,使用 RealmResults<PostUserItinerary> 直接,然后删除您直接拨打的任何电话 adapter.notifyDataSetChanged(); .

Activity 和 Adapter 在王国的样本中。

class MyListAdapter extends RealmBaseAdapter<PostUserItinerary> implements ListAdapter {

    private static class ViewHolder {
        TextView countText;
        CheckBox deleteCheckBox;
    }

    MyListAdapter(OrderedRealmCollection<Counter> realmResults) {
        super(realmResults);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        if (convertView == null) {
            convertView = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.row, parent, false);
            viewHolder = new ViewHolder();
            viewHolder.countText = (TextView) convertView.findViewById(R.id.textview);
            viewHolder.deleteCheckBox = (CheckBox) convertView.findViewById(R.id.checkBox);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        final PostUserItinerary item = getItem(position);
        ...
        return convertView;
    }
}

和

public class ListViewExampleActivity extends AppCompatActivity {

    private Realm realm;
    private MyListAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_listview);
        realm = Realm.getDefaultInstance();

        // RealmResults are "live" views, that are automatically kept up to date, even when changes happen
        // on a background thread. The RealmBaseAdapter will automatically keep track of changes and will
        // automatically refresh when a change is detected.
        adapter = new MyListAdapter(realm.where(PostUserItinerary.class).findAllAsync());