**//ViewModel类中的更新函数我认为主要问题是在ViewModel类中，因为它没有让它更新。我试过许多解决办法，但没有一个对我有帮助

fun updateTask(task : ToDoItem, isChecked : Boolean) = viewModelScope.launch {
    val updateTask = task.copy(isCompleted = isChecked)
    repository.updateTask(updateTask)
    Log.d("Msg", updateTask.toString())
}

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适配器类

class TodoAdapter(private val listener : OnItemClick) : ListAdapter<ToDoItem, TodoAdapter.TodoViewHolder>(DiffCallBack()){

    inner class TodoViewHolder(itemView : View) : RecyclerView.ViewHolder(itemView){

        private val tvTask: TextView = itemView.findViewById(R.id.tvTask)
        private val checkBox: CheckBox = itemView.findViewById(R.id.checkBox)

        init {
            checkBox.setOnClickListener{
                val position = adapterPosition
                if(position != RecyclerView.NO_POSITION){
                    val task = getItem(position)
                    listener.onCheckBoxClick(task, checkBox.isChecked)
                }
            }
        }

        fun bind(item: ToDoItem) {
            tvTask.text = item.task
            checkBox.isChecked = item.isCompleted
            tvTask.paint.isStrikeThruText = item.isCompleted
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): TodoViewHolder {
        val viewHolder = LayoutInflater.from(parent.context).inflate(R.layout.task_layout, parent, false)
        return TodoViewHolder(viewHolder)
    }

    override fun onBindViewHolder(holder: TodoViewHolder, position: Int) {
        val item = getItem(position)
        holder.bind(item)
    }

    interface OnItemClick{
        fun onCheckBoxClick(task : ToDoItem, isChecked : Boolean)
    }
}

class DiffCallBack : DiffUtil.ItemCallback<ToDoItem>(){
    override fun areItemsTheSame(oldItem: ToDoItem, newItem: ToDoItem): Boolean {
        return oldItem.id == newItem.id
    }

    override fun areContentsTheSame(oldItem: ToDoItem, newItem: ToDoItem): Boolean {
        return oldItem.id == newItem.id
    }

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// Main Activity类
在main中，我实现了在viewModel中调用update（）的接口

mAdapter = TodoAdapter(this)
    binding.recyclerView.layoutManager = LinearLayoutManager(this)
    binding.recyclerView.adapter = mAdapter

    viewModel = ViewModelProvider(this,
             ViewModelProvider.AndroidViewModelFactory.getInstance(application))[ToDoViewModel::class.java]
    viewModel.tasks.observe(this, Observer {
        mAdapter.submitList(it)
    })
}

override fun onCheckBoxClick(task: ToDoItem, isChecked: Boolean) {
    viewModel.updateTask(task, isChecked)
}

型

仓库类

suspend fun updateTask(task : ToDoItem){
        dao.updateTask(task)
    }

型

道班

@Update
    suspend fun updateTask(task : ToDoItem)

型

数据类

@Entity(tableName = "todo_table")
data class ToDoItem (
    val task : String,
    var isCompleted : Boolean = false
){
    @PrimaryKey(autoGenerate = true) var id : Int = 0
}

型