数据库

最新推荐文章于 2024-07-15 08:30:00 发布

chenxchhh

最新推荐文章于 2024-07-15 08:30:00 发布

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CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/chenxchhh/article/details/89301176

本文介绍了一种使用SQLite数据库进行数据增删查改的实用方法，并通过Fragment和RecyclerView实现了数据的有效展示，涵盖了数据库初始化、数据添加及加载等关键步骤。

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=========Utils=
private OneDao dao;

private ResultUtils() {

}

private static ResultUtils resultUtils = null;
public static ResultUtils getResultUtils() {
synchronized (ResultUtils.class) {
if (resultUtils == null) {
resultUtils = new ResultUtils();
}
}
return resultUtils;
}

public void init(Context context) {
DaoMaster.DevOpenHelper helper = new DaoMaster.DevOpenHelper(context, “datas”);
SQLiteDatabase db = helper.getWritableDatabase();
DaoMaster daoMaster = new DaoMaster(db);
dao = daoMaster.newSession().getOneDao();
}

public void add(One bean) {
List list = dao.loadAll();
for (int i = 0; i < list.size(); i++) {
One bean1 = list.get(i);
if (bean.getCommodityId().equals(bean1.getCommodityId())) {
dao.delete(bean1);
}
}
//Log.i(“aaa”,bean.toString());
dao.insert(bean);
}

public List loadAll() {
List list = dao.loadAll();
return list;
}
展示==
public class Fragment01 extends Fragment implements Views {
@BindView(R.id.recy1)
RecyclerView recy1;
@BindView(R.id.recy2)
RecyclerView recy2;
@BindView(R.id.recy3)
RecyclerView recy3;
private Presenter presenter;
private FragmentAdapter adapter;
private List list1 = new ArrayList<>();
private String url=“http://172.17.8.100/small/commodity/v1/commodityList”;

@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View view = View.inflate(getActivity(),R.layout.frag01,null);
    ButterKnife.bind(this,view);
    return view;
}

@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    presenter = new Presenters(new Models(),this);

    adapter = new FragmentAdapter(getActivity());

    LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity());
    linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
    recy1.setLayoutManager(linearLayoutManager);
    recy1.setAdapter(adapter);
    presenter.get(0,url);
}


@Override
public void success(int type, String data) {
    JsonBean bean = new Gson().fromJson(data, JsonBean.class);
    List<One> list1 = bean.getResult().getMlss().getCommodityList();
    adapter.setData(list1);
}

@Override
public void error() {

}