如何将复选框状态保存到房间数据库

Question

我试图找到一种方法来保存复选框的状态到房间数据库，但当我点击复选框并重新打开应用程序时，它的状态并没有改变。我不知道我哪里出错了。我已经搜索了前面的问题，但找不到解决办法。下面是我的代码和感谢。

@Entity(tableName = "todo_table")
public class Todo {
    @PrimaryKey(autoGenerate = true)
    public int id;
    public String title;
    public Boolean isChecked;

    public Todo(String title, Boolean isChecked) {
        this.title = title;
        this.isChecked = isChecked;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public Boolean getChecked() {
        return isChecked;
    }

    public void setChecked(Boolean checked) {
        isChecked = checked;
    }
}

@Dao
public interface TodoDAO {
    @Insert
    void Insert(Todo todo);

   
    @Update
    void Update(Todo todo);

    @Query("SELECT * FROM todo_table ORDER BY id ASC")
    LiveData<List<Todo>> getAllTodo();

}

@Database(entities = Todo.class,version = 1,exportSchema = false)
public abstract class TodoDatabase extends RoomDatabase {
    private static TodoDatabase instance;
    public abstract TodoDAO todoDAO();

    public static synchronized TodoDatabase getInstance(Context context){
        if(instance == null){
            instance = Room.databaseBuilder(context.getApplicationContext(),
                    TodoDatabase.class,"todo_database").fallbackToDestructiveMigration()
                    .addCallback(roomCallBack)
                    .build();
        }
        return instance;
    }

    private static  RoomDatabase.Callback roomCallBack = new RoomDatabase.Callback(){
        @Override
        public void onCreate(@NonNull SupportSQLiteDatabase db) {
            super.onCreate(db);
            new PopulateDbAsyncTask(instance).execute();
        }
    };

    private static class PopulateDbAsyncTask extends AsyncTask<Void,Void,Void> {
        private TodoDAO todoDAO;

        private PopulateDbAsyncTask(TodoDatabase database) {
            todoDAO = database.todoDAO();
        }

        @Override
        protected Void doInBackground(Void... voids) {
            return null;
        }
    }
}

public class TodoRepository {
    private TodoDAO todoDAO;
    private LiveData<List<Todo>> todo;

    public TodoRepository(Application application){
        TodoDatabase database = TodoDatabase.getInstance(application);
        todoDAO = database.todoDAO();
        todo = todoDAO.getAllTodo();
    }

    public void insert(Todo todo){
        new InsertNoteAsyncTask(todoDAO).execute(todo);
    }

    public LiveData<List<Todo>> getTodo() {
        return todo;
    }

    public void update(Todo todo){
        new UpdateTodoAsyncTask(todoDAO).execute(todo);
    }

    private static class InsertNoteAsyncTask extends AsyncTask<Todo,Void,Void> {
        private TodoDAO todoDAO;

        private InsertNoteAsyncTask(TodoDAO todoDAO){
            this.todoDAO = todoDAO;
        }

        @Override
        protected Void doInBackground(Todo... todos) {
            todoDAO.Insert(todos[0]);
            return null;
        }
    }

    private static class UpdateTodoAsyncTask extends AsyncTask<Todo,Void,Void> {
        private TodoDAO todoDAO;

        private UpdateTodoAsyncTask(TodoDAO todoDAO){
            this.todoDAO = todoDAO;
        }

        @Override
        protected Void doInBackground(Todo... todos) {
            todoDAO.Update(todos[0]);
            return null;
        }
    }
}

public class TodoViewModel extends AndroidViewModel {

    private TodoRepository repository;
    private LiveData<List<Todo>> todo;

    public TodoViewModel(@NonNull Application application) {
        super(application);

        repository = new TodoRepository(application);
        todo = repository.getTodo();
    }

    public void insert(Todo todo){
        repository.insert(todo);
    }

    public void update(Todo todo){
        repository.update(todo);
    }

    public LiveData<List<Todo>> getTodo(){
        return todo;
    }
}

TodoAdapter

public class TodoAdapter extends RecyclerView.Adapter<TodoAdapter.ViewHolder>{
    private List<Todo> todos = new ArrayList<>();

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        return new ViewHolder(TodoItemBinding.inflate(LayoutInflater.from(parent.getContext()),parent,false));
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        Todo currentTodo = todos.get(holder.getAbsoluteAdapterPosition());
        holder.binding.tvTitle.setText(currentTodo.getTitle());
        holder.binding.checkBox.setChecked(currentTodo.getChecked());
        holder.binding.checkBox.setOnCheckedChangeListener(null);
        holder.binding.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked){
                    holder.binding.checkBox.setChecked(true);
                }else{
                    holder.binding.checkBox.setChecked(false);
                }
            }
        });
    }

    @Override
    public int getItemCount() {
        if(todos != null){
            return todos.size();
        }else{
            return 0;
        }

    }

    public void setTodos(List<Todo> todos){
        this.todos = todos;
        notifyDataSetChanged();
    }

    class ViewHolder extends RecyclerView.ViewHolder{
        private TodoItemBinding binding;

        public ViewHolder(TodoItemBinding bind){
            super(bind.getRoot());
            this.binding = bind;
        }
    }
}

主体活动

public class MainActivity extends AppCompatActivity {

    private ActivityMainBinding binding;
    private TodoItemBinding todoItemBinding;
    private TodoViewModel todoViewModel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityMainBinding.inflate(getLayoutInflater());
        todoItemBinding = TodoItemBinding.inflate(getLayoutInflater());
        View view = binding.getRoot();
        setContentView(view);

        RecyclerView recyclerView = binding.recyclerView;
        recyclerView.setLayoutManager(new LinearLayoutManager(this));

        TodoAdapter todoAdapter = new TodoAdapter();
        recyclerView.setAdapter(todoAdapter);

        todoViewModel = new ViewModelProvider(this).get(TodoViewModel.class);
        todoViewModel.getTodo().observe(this, new Observer<List<Todo>>() {
            @Override
            public void onChanged(List<Todo> todos) {
               todoAdapter.setTodos(todos);
            }
        });

        binding.btnAdd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                addTodo();
            }
        });

        todoItemBinding.checkBox.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Boolean isChecked = todoItemBinding.checkBox.isChecked();
                Todo todo;
                if (isChecked){
                    todo = new Todo(binding.editText.getText().toString(), true);
                }else{
                    todo = new Todo(binding.editText.getText().toString(), false);
                }
                todoViewModel.update(todo);
            }
        });
    }

    private void addTodo() {
        String title = binding.editText.getText().toString();
        Todo todo = new Todo(title,false);
        todoViewModel.insert(todo);
        binding.editText.setText("");
        closeKeyboard();
    }

    private void closeKeyboard(){
        View view = this.getCurrentFocus();
        if (view != null) {
            InputMethodManager manager = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
            manager.hideSoftInputFromWindow(view.getWindowToken(), 0);
        }
    }
}

Answer 1

使用SharedPrefs可以节省大量时间。更改以下代码:InsideMainActivity

public void onClick(View v) {
       Boolean isChecked = todoItemBinding.checkBox.isChecked();
       Todo todo;
       if (isChecked){
           todo = new Todo(binding.editText.getText().toString(), true);
       }else{
            todo = new Todo(binding.editText.getText().toString(), false); }       
       todoViewModel.update(todo);
}

用这个

public void onClick(View v) {
       Boolean isChecked =PreferenceManager.getDefaultSharedPreferences(this)
       .getBoolean("checkBox1", false);
       checkBox1.setChecked(checked);
        Todo todo;
       if (isChecked){
           todo = new Todo(binding.editText.getText().toString(), true);
       }else{
            todo = new Todo(binding.editText.getText().toString(), false); }       
       todoViewModel.update(todo);
}