二月12日

　　今天将Fragment中的代码完成了首先是第一个fragment：

package com.eb.writeaccount;


import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.os.Bundle;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.LiveData;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProviders;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.recyclerview.widget.DefaultItemAnimator;
import androidx.recyclerview.widget.DividerItemDecoration;
import androidx.recyclerview.widget.ItemTouchHelper;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.SearchView;

import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;

import java.util.List;


/**
 * A simple {@link Fragment} subclass.
 */
public class wos extends Fragment {

    private MyViewModel myViewModel;
    private RecyclerView recyclerView;
    private MyAdapter myAdapter;
    private LiveData<List<Word>> filteredWords;
    private static final String VIEW_TYPE_SHP = "view_type_shp";
    private static final String IS_USING_CARD_VIEW = "is_using_card_view";
    private List<Word> allWords;
    private boolean undoAction;
    private DividerItemDecoration dividerItemDecoration;

    public wos() {
        // Required empty public constructor
        setHasOptionsMenu(true);
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        AlertDialog.Builder builder = new AlertDialog.Builder(requireActivity());
        builder.setTitle("清空数据");
        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                myViewModel.deleteAllWords();
            }
        });
        builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {

            }
        });
        builder.create();
        builder.show();
        return super.onOptionsItemSelected(item);
    }
    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        super.onCreateOptionsMenu(menu, inflater);
        inflater.inflate(R.menu.main_menu, menu);
        SearchView searchView = (SearchView) menu.findItem(R.id.app_bar_search).getActionView();
        searchView.setMaxWidth(1000);
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                String pattern = newText.trim();
              filteredWords.removeObservers(getViewLifecycleOwner());      //先移除之前在onActivityCreated中添加的observer
                filteredWords = myViewModel.findWordsWithPattern(pattern);
                filteredWords.observe(getViewLifecycleOwner(), new Observer<List<Word>>() {
                    @Override
                    public void onChanged(List<Word> words) {
                        int temp = myAdapter.getItemCount();
                        allWords = words;
                        if (temp != words.size()) {
                            myAdapter.submitList(words);

                        }
                    }
                });
                return true;
            }
        });
    }
    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        myViewModel = ViewModelProviders.of(requireActivity()).get(MyViewModel.class);
        recyclerView = requireActivity().findViewById(R.id.recycle);
        recyclerView.setLayoutManager(new LinearLayoutManager(requireActivity()));
    myAdapter=new MyAdapter(myViewModel);
    recyclerView.setAdapter(myAdapter);
        recyclerView.setItemAnimator(new DefaultItemAnimator() {
            @Override
            public void onAnimationFinished(@NonNull RecyclerView.ViewHolder viewHolder) {
                super.onAnimationFinished(viewHolder);
                LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
                if (linearLayoutManager != null) {
                    int firstPosition = linearLayoutManager.findFirstVisibleItemPosition();
                    int lastPosition = linearLayoutManager.findLastVisibleItemPosition();
                    for (int i = firstPosition; i <= lastPosition; i++) {
                        MyAdapter.MyViewHolder holder = (MyAdapter.MyViewHolder) recyclerView.findViewHolderForAdapterPosition(i);
                        if (holder != null) {
                            holder.textViewNumber.setText(String.valueOf(i + 1));

                        }
                    }
                }

            }
        });

        dividerItemDecoration = new DividerItemDecoration(requireActivity(),DividerItemDecoration.VERTICAL);
        recyclerView.addItemDecoration(dividerItemDecoration);


        //recyclerView.setAdapter(myAdapter1);
        filteredWords = myViewModel.getAllWordsLive();
        filteredWords.observe(getViewLifecycleOwner(), new Observer<List<Word>>() {
            @Override
            public void onChanged(List<Word> words) {
                int temp = myAdapter.getItemCount();
                allWords = words;
                if (temp != words.size()) {
                    if (temp < words.size() && !undoAction) {

                        recyclerView.smoothScrollBy(0,-200);


                    }
                    undoAction = false;

                    myAdapter.submitList(words);
                }
            }
        });
        new ItemTouchHelper(new ItemTouchHelper.SimpleCallback(0,ItemTouchHelper.START | ItemTouchHelper.END) {
            @Override
            public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) {
//               Word wordFrom=allWords.get(viewHolder.getAdapterPosition());
//                Word wordto=allWords.get(target.getAdapterPosition());
//                int i=wordFrom.getId();
//                wordFrom.setId(wordto.getId());
//                wordto.setId(i);
//                myViewModel.updateWords(wordFrom,wordto);
//                myAdapter.notifyItemMoved(viewHolder.getAdapterPosition(),target.getAdapterPosition());
                return false;
            }

            @Override
            public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int direction) {
                final Word word=allWords.get(viewHolder.getAdapterPosition());
                myViewModel.deleteWords(word);
                Snackbar.make(requireActivity().findViewById(R.id.wosFragment),"删除了一个字符",Snackbar.LENGTH_SHORT).setAction("撤销", new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        myViewModel.insertWords(word);
                    }
                }).show();
            }
        }).attachToRecyclerView(recyclerView);


        FloatingActionButton floatingActionButton = requireActivity().findViewById(R.id.floatingActionButton);
        floatingActionButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                NavController navController = Navigation.findNavController(v);
                navController.navigate(R.id.action_wos_to_addfragment);
            }
        });

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

}

然后将输入的Fgrment写完

package com.eb.writeaccount;


import android.content.Context;
import android.os.Bundle;

import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentActivity;
import androidx.lifecycle.ViewModelProviders;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;

import android.text.Editable;
import android.text.TextWatcher;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;


/**
 * A simple {@link Fragment} subclass.
 */
public class addfragment extends Fragment {
    private Button buttonSubmit;
    private EditText editTextmoney,editTexttime;
    private MyViewModel myViewModel;

    public addfragment() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_addfragment, container, false);
    }
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        FragmentActivity activity = requireActivity();
        myViewModel = ViewModelProviders.of(activity).get(MyViewModel.class);
        buttonSubmit = activity.findViewById(R.id.button);
        editTextmoney = activity.findViewById(R.id.editTextmoney);
        editTexttime = activity.findViewById(R.id.editTexttime);
        buttonSubmit.setEnabled(false);
        editTextmoney.requestFocus();
        InputMethodManager imm = (InputMethodManager) activity.getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.showSoftInput(editTextmoney,0);

        TextWatcher textWatcher = new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                String english = editTextmoney.getText().toString().trim();
                String chinese = editTexttime.getText().toString().trim();
                buttonSubmit.setEnabled(!english.isEmpty() && !chinese.isEmpty());
            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        };
        editTextmoney.addTextChangedListener(textWatcher);
        editTexttime.addTextChangedListener(textWatcher);
        buttonSubmit.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String english = editTextmoney.getText().toString().trim();
                String chinese = editTexttime.getText().toString().trim();
                Word word = new Word(english,chinese);
                myViewModel.insertWords(word);
                NavController navController = Navigation.findNavController(v);
                navController.navigateUp();
                InputMethodManager imm = (InputMethodManager) requireActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
                imm.hideSoftInputFromWindow(v.getWindowToken(),0);
            }
        });
    }

}