在选择一个项目时，取消选择 Groupie RecyclerView 的所有其他项目

Question

我看到这个问题问了几次，但也许是因为我正在使用Groupie库将物品添加到我的适配器中，我无法在选择其中一个时取消选择其他项目（类似于无线电按钮功能）。我正在尝试将更改通知适配器并在某种程度上获得所选项目的位置，但我认为如果有人可以为我指出这一点，我可能仍然会遗漏一些东西。

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)


    rvOptions.layoutManager = LinearLayoutManager(activity)
    adapter = GroupAdapter()
    rvOptions.adapter = adapter


    viewModel = ViewModelProviders.of(activity as MainActivity).get(TestViewModel::class.java)
    val myViewModel = ViewModelProvider(
        this, MyViewModelFactoryForHashMap(arguments?.getString("headerText"))
    ).get(TestViewModel::class.java)

    myViewModel.userMutableLiveData.observe(this, userListUpdateObserver)

}


private val userListUpdateObserver: Observer<Array<ModelTest>?> =
    Observer { userArrayList ->
        for (s in userArrayList!!) {
            adapter.add(
                RecyclerDialogOptionsItem(
                    activity as MainActivity,
                    s.title,
                    s.selected!!,
                    this@MyDialogFragment
                )
            )
        }
    }

override fun onClickItem( position: Int) {

    adapter.notifyDataSetChanged()
}

}

这里是我的适配器，这样的想法是，当一个项目处于选定状态时，与其关联的 imageView 将是可见的，而对于所有其他项目将变得不可见。

class RecyclerDialogOptionsItem(
private val activity: MainActivity,
private val title: String?,
private var selected: Boolean,
private val adapterListener: AdapterListener
) : Item<GroupieViewHolder>() {

companion object {
    var clickListener: AdapterListener? = null
}


override fun bind(viewHolder: GroupieViewHolder, position: Int) {

    var selected_position = -1;

    viewHolder.apply {

        with(viewHolder.itemView) {

            tvTitle.text = title

            clickListener = adapterListener

            itemView.setOnClickListener {

                clickListener?.onClickItem(adapterPosition)


                selected = true

                selected_position = position
                if (selected) {

                    ivChecked.visible()

                } else {
                    ivChecked.invisible()
                }

            }


        }

        selected_position = adapterPosition
        
    }

}


override fun getLayout() = R.layout.rv_options_item_row


interface AdapterListener {
    fun onClickItem(position: Int)
}

}

非常感谢。

Answer 1

第一个选项：创建您的适配器并在适配器中创建一个局部变量并检查选择的位置是变量。

第二个选项： 在名为 selected_position 的 Activity 中创建变量。 当调用的函数 onClickItem 更新此变量并通知适配器更改时。 在您的项目中检查活动中的变量，例如：

// Activity
selected_position = -1

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)


    rvOptions.layoutManager = LinearLayoutManager(activity)
    adapter = GroupAdapter()
    rvOptions.adapter = adapter


    viewModel = ViewModelProviders.of(activity as MainActivity).get(TestViewModel::class.java)
    val myViewModel = ViewModelProvider(
        this, MyViewModelFactoryForHashMap(arguments?.getString("headerText"))
    ).get(TestViewModel::class.java)

    myViewModel.userMutableLiveData.observe(this, userListUpdateObserver)

}


private val userListUpdateObserver: Observer<Array<ModelTest>?> =
    Observer { userArrayList ->
        for (s in userArrayList!!) {
            adapter.add(
                RecyclerDialogOptionsItem(
                    activity as MainActivity,
                    s.title,
                    s.selected!!,
                    this@MyDialogFragment
                )
            )
        }
    }

override fun onClickItem( position: Int) {
    selected_position = position
    adapter.notifyDataSetChanged()
}

}
// Item

class RecyclerDialogOptionsItem(
private val activity: MainActivity,
private val title: String?,
private var selected: Boolean,
private val adapterListener: AdapterListener
) : Item<GroupieViewHolder>() {

companion object {
    var clickListener: AdapterListener? = null
}


override fun bind(viewHolder: GroupieViewHolder, position: Int) {


    viewHolder.apply {

        with(viewHolder.itemView) {

            tvTitle.text = title

            clickListener = adapterListener
            if (activity.selected_position == position) {
                    ivChecked.visible()

                } else {
                    ivChecked.invisible()
                }

            itemView.setOnClickListener {
                clickListener?.onClickItem(adapterPosition)

            }


        }

        
    }

}


override fun getLayout() = R.layout.rv_options_item_row


interface AdapterListener {
    fun onClickItem(position: Int)
}

}