判断是否有网没有从数据库中取值_怎么判断有没有从数据库查询到数据-优快云博客

本文链接：https://blog.youkuaiyun.com/weixin_43812075/article/details/84672147

本文介绍了一种在无网络连接情况下加载离线数据的方法。通过检查网络状态，若无网络，则从本地数据库查询数据并填充到列表中；若有网络，则显示提示信息。此策略确保了应用在不同网络环境下都能提供良好的用户体验。

判断是否有网没有从数据库中取值

public class Frag02 extends Fragment {

    private ArrayList<JsonBean.DataBean> list = new ArrayList<JsonBean.DataBean>();
    private Dao dao;
    private ListView ListView;
    private MyListAdapter adapter;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view1 = inflater.inflate(R.layout.frag02,container,false);
        dao = new Dao(getActivity());
        ListView = view1.findViewById(R.id.listView);

        if (!MyNewWork.isConn(getActivity())){
            Cursor query = dao.query("aaa", null, null, null, null, null, null, null);
            if (query.moveToFirst()) {
               do {
                   String ssss = query.getString(query.getColumnIndex("name"));
                   String pass = query.getString(query.getColumnIndex("pass"));
                   list.add(new JsonBean.DataBean("","",ssss,pass));

               }while (query.moveToNext());
            }
            query.close();

        }else{
            Toast.makeText(getActivity(),"有网络",Toast.LENGTH_LONG).show();
        }

        adapter = new MyListAdapter(getActivity(), list);
        ListView.setAdapter(adapter);

        return view1;
    }
}

判断有没有网
有：MyNewWork.isConn(getActivity())
没有：！MyNewWork.isConn(getActivity())

if (!MyNewWork.isConn(getActivity())){
           

        }else{
            Toast.makeText(getActivity(),"有网络",Toast.LENGTH_LONG).show();
        }