如何将对象从 RecyclerView 添加到数据库 MVVM

Question

我想通过单击图标将我的 RecyclerView 中的对象添加到数据库。我使用 MVVM 模式，所以我应该在 Fragment 中添加一个对象。我有 2 个回调，第二个应该在单击时向数据库添加一个对象。如何获取对象以便在适配器回调的 viewModel.saveWord() 方法中使用它。或者我应该在其他地方做？

RecyclerView 适配器：

class SearchDefAdapter(
    private var infoListener: OnItemClickListener,
    private var addListener: OnItemClickListener
):
    ListAdapter<Def, SearchDefViewHolder>(differCallback) {
    interface OnItemClickListener {
        fun onItemClick(position: Int)
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): SearchDefViewHolder {
        return SearchDefViewHolder(
            SearchWordCardBinding.inflate(
                LayoutInflater.from(parent.context),
                parent,
                false
            ),
            addListener,
            infoListener
        )
    }

    override fun onBindViewHolder(holder: SearchDefViewHolder, position: Int) {
        holder.bind(getItem(position))
    }
}

RecyclerView ViewHolder:

class SearchDefViewHolder(
    private val binding: SearchWordCardBinding,
    addListener: SearchDefAdapter.OnItemClickListener,
    infoListener: SearchDefAdapter.OnItemClickListener
): RecyclerView.ViewHolder(binding.root) {
    fun bind(data: Def) {
        with (binding) {
            searchCardTv.text = "${data.text} - ${data.tr[0].text}"
        }
    }

    init {
        binding.addSearchCard.setOnClickListener {
            addListener.onItemClick(adapterPosition)

        }

        binding.infoSearchCard.setOnClickListener {
            infoListener.onItemClick(adapterPosition)
        }
    }
}

RecyclerView 不同回调：

val differCallback = object : DiffUtil.ItemCallback<Def>() {
    override fun areItemsTheSame(oldItem: Def, newItem: Def): Boolean {
        return oldItem.text == newItem.text
    }

    override fun areContentsTheSame(oldItem: Def, newItem: Def): Boolean {
        return oldItem == newItem
    }
}

片段中的适配器初始化：

searchDefAdapter = SearchDefAdapter(
            object : SearchDefAdapter.OnItemClickListener {
                override fun onItemClick(position: Int) {
                    if (!translationsList.isNullOrEmpty()){
                        val bundle = Bundle()
                        bundle.putStringArray(INFO_BUNDLE_ID, translationsList[position])
                        val wordFragment = WordFragment()
                        wordFragment.arguments = bundle
                        parentFragmentManager.beginTransaction().apply {
                            replace(R.id.searchFragment, wordFragment)
                            commit()
                        }
                    }
                }
            },
            object : SearchDefAdapter.OnItemClickListener {
                override fun onItemClick(position: Int) {
                    //viewModel.saveWord()
                }
            }
        )

Answer 1

将回调参数从位置更改为项目类型。

interface OnItemClickListener {
    fun onItemClick(def: Def)
}

//...

class SearchDefViewHolder(
    private val binding: SearchWordCardBinding,
    addListener: SearchDefAdapter.OnItemClickListener,
    infoListener: SearchDefAdapter.OnItemClickListener
): RecyclerView.ViewHolder(binding.root) {

    private lateinit var def: Def

    fun bind(data: Def) {
        with (binding) {
            searchCardTv.text = "${data.text} - ${data.tr[0].text}"
        }
        def = data
    }

    init {
        binding.addSearchCard.setOnClickListener {
            addListener.onItemClick(def)
        }

        binding.infoSearchCard.setOnClickListener {
            infoListener.onItemClick(def)
        }
    }
}

然后在你的片段中，你的监听器更容易定义并直接给你写入数据库的项目。

如何将对象从 RecyclerView 添加到数据库 MVVM

How to add an obejct from RecyclerView to database MVVM

android

kotlin

mvvm

android-recyclerview

onclicklistener