Question

我在SQLite android中存储标题，缩略图，id并在recyclerview中显示。我创建了所有方法，即在我的sqlite帮助器类中获取数据，添加，删除和更新，并在我的片段android中调用这些方法。

但问题是当我删除或添加项目到sqlite时，它没有刷新。是的，我在片段类中定义了adapter.notifydatasetChanged()。

示例：

这是我的sqlite openhelper类：

public List<dataModel> getDatabase();
public void addData(dataModel data);
public void deleteData(dataModel data);

我在片段类中调用这些方法，而我正在分配 getDatabase()列在片段中。

提前致谢。编辑1：

public class LightFragment extends Fragment {

RecyclerView mRecyclerView;
FloatingActionButton addLightTitle,allLightsOff;
ArrayList<LightTitle> lightTitle;
RecyclerView.LayoutManager mLayoutManager;

EditText edxLightName;
Button btnLightName;

SQLiteDatabase  db;
LDbHelper lHelper;
ArrayList<LightPojo> mLightPojos = new ArrayList<>();
LightRecyclerView li;


@SuppressLint("ValidFragment")
public LightFragment(Context mContext) {

    lHelper = new LDbHelper(mContext);

}

public LightFragment() {
}





@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_light, container, false);
}

@Override
public void onPause() {
    super.onPause();
    mLightPojos = lHelper.getLightData();

}

@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    mRecyclerView = view.findViewById(R.id.light_frag);
    addLightTitle = view.findViewById(R.id.fab_add_light_title);
    allLightsOff = view.findViewById(R.id.fab_off_all_lights);

    mLayoutManager = new LinearLayoutManager(getContext(),LinearLayoutManager.HORIZONTAL,false);
    mLightPojos = lHelper.getLightData();
           li = new LightRecyclerView(getContext(),mLightPojos);
    mRecyclerView.setLayoutManager(mLayoutManager);
    mRecyclerView.setAdapter(li);
    li.notifyDataSetChanged();

    mRecyclerView.addOnItemTouchListener(new RecyclerTouchListener(getActivity(),mRecyclerView,new ClickListener(){

        @Override
        public void onClick(View view, int position) {
            Log.d("BT","clicked" + mLightPojos.get(position).getName());
            //toast("clicked" + position );

            if (!mLightPojos.get(position).isClicked()){
                ImageView lightPopUp = view.findViewById(R.id.row_light_thumbnail);
                lightPopUp.setImageResource(R.drawable.light_on);
                //DrawableCompat.setTint(lightPopUp.getDrawable().mutate(), ContextCompat.getColor(getContext(), R.color.white));
                toast(mLightPojos.get(position).getName() + "light on");
                Log.d("BT","clicked" + mLightPojos.get(position).isClicked());
                //mLightPojos.get(position).setClicked(true);
                LightPojo pojo = new LightPojo(mLightPojos.get(position).getId(),R.drawable.light_on,true);
                lHelper.upDateState(pojo);
            }else {
                ImageView lightPopUp = view.findViewById(R.id.row_light_thumbnail);
                toast(mLightPojos.get(position).getName() + "light off");
                lightPopUp.setImageResource(R.drawable.light_off);
                //DrawableCompat.setTint(lightPopUp.getDrawable().mutate(), ContextCompat.getColor(getContext(), R.color.colorAccent));
                Log.d("BT","clicked" + mLightPojos.get(position).isClicked());
                //mLightPojos.get(position).setClicked(false);
                //lHelper.upDateState(position,R.drawable.light_off,false);
                LightPojo pojo = new LightPojo(mLightPojos.get(position).getId(),R.drawable.light_off,false);
                lHelper.upDateState(pojo);
            }



        }

        @Override
        public void onLongClick(View view, final int position) {
            toast("long pressed at " + position);
            final Dialog eDialog = new Dialog(getActivity());
            eDialog.setContentView(R.layout.edit_light_name);
            //EditText editLightName = eDialog.findViewById(R.id.edit_light_name_edx);
            //final String editedLightName = editLightName.getText().toString();
            Button deleteLightName = eDialog.findViewById(R.id.btn_delete_light_name);
            Button updateLightName = eDialog.findViewById(R.id.btn_update_light_name);
            eDialog.show();
           // eDialog.setTitle("Edit light name");



            updateLightName.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    //lightTitle.set(position,editLightName.getText().toString());
                    //Log.d("BT",editedLightName);
                    EditText editLightName = eDialog.findViewById(R.id.edit_light_name_edx);

                    //lightTitle.set(position,new LightTitle(editLightName.getText().toString(),false));
                    LightPojo pojo = new LightPojo(mLightPojos.get(position).getId(),editLightName.getText().toString());
                    lHelper.editName(pojo);
                    lHelper.getLightData();
                    li.notifyDataSetChanged();
                    eDialog.dismiss();
                }
            });

            deleteLightName.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    //lightTitle.remove(position);
                    LightPojo pojo = new LightPojo(mLightPojos.get(position).getId());
                    lHelper.delete(pojo);
                    li.notifyItemChanged(position);
                    //li.notifyDataSetChanged();
                    eDialog.dismiss();
                }
            });


        }
    }));

    addLightTitle.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //toast("clicked fab button");

            //LightTitleDialog titleDialog = new LightTitleDialog();
            //titleDialog.show(getActivity().getFragmentManager(),"title");
            final Dialog mDialog = new Dialog(getActivity());
            mDialog.setTitle("Add light name");
            mDialog.setContentView(R.layout.add_light_title);
            edxLightName = mDialog.findViewById(R.id.edt_light_title);
            btnLightName = mDialog.findViewById(R.id.btn_add_title);
            mDialog.show();

            btnLightName.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    //toast("Add light");
                    if (edxLightName.getText().length() != 0){
                        String newLightName = edxLightName.getText().toString();
                        //lightTitle.add(new LightTitle(newLightName,false));
                        //add(newLightName,R.id.utilities_thumbnail,false);
                        lHelper.insertData(newLightName,R.drawable.light_off,false);
                        li.notifyDataSetChanged();
                        mDialog.dismiss();
                    }else {
                        toast("Please enter light name");
                    }
                }
            });


        }
    });

Answer 1

更新数据模型后，请调用以下方法。

 adapter.notifyItemRemoved(position);

这将更新适配器有关从列表中删除元素的信息。

Answer 2

更新数据模型后，从Fragment或Activity调用adapter.notifydatasetChanged()（无论您使用什么）。然后将更新recyclerView。

Answer 3

是的，我发现单击时我必须显式更改ArrayList。除了数据库更新。

将值更新到SQLite调用适配器方法以进行内部更新值之后。每次更新数据时都不需要获取SQLite数据。

如何在sqlite android片段中更改或删除数据时刷新recyclelerview？

3 个答案: