在 Android Studio 中使用 Recycler View 重置单选按钮状态

Question

I have a problem using radio button inside a recycler view, the radio button works fine, but when I go back to the previous fragment, and go back to the fragment where the recyclerview is included, the radio button state is checked on the last item that I clicked, I want to reset the state of the radio button. Here's a screenshot of the example.

Here is where I navigate into a fragment that include the recyclerView for the first time : Expected

And here is when I clicked one of the choices, go back to the previous fragment, and go back to the fragment where the recyclerView is included : Current State

Here is my code in fragment, adapter, and viewholder

Fragment :

private fun initializeRecyclerView(){
    val transactionTypeLayoutManager = GridLayoutManager(context, 2)
    
    val list = TransactionType.values().toList()
    val transactionTypeAdapter = ManualMixTransactionTypeAdapter(list)
    binding?.recyclerViewTransactionType?.layoutManager = transactionTypeLayoutManager
    binding?.recyclerViewTransactionType?.adapter = transactionTypeAdapter

    transactionTypeAdapter.onTransactionTypeClicked = {
        viewModel.setTransactionType(it.name)
        Toast.makeText(context, "${it.name}", Toast.LENGTH_SHORT).show()
    }
}

Adapter :

var onTransactionTypeClicked: ((TransactionType) -> Unit)? = null

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): TransactionTypeViewHolder {
    val layoutInflater: LayoutInflater = LayoutInflater.from(parent.context)
    val binding: ViewholderTransactionTypeBinding = ViewholderTransactionTypeBinding.inflate(layoutInflater, parent, false)
    return TransactionTypeViewHolder(binding)
}

override fun onBindViewHolder(holder: TransactionTypeViewHolder, position: Int) {
    holder.binding.rbTransactionType.setText(transactionType[position].key)
    holder.render(
        data = transactionType[position],
        dataIndex = position,
        adapterListener = {
            val oldTransactionType = transactionType.find { transactionType -> transactionType.isItemSelected }

            oldTransactionType?.apply { isItemSelected = false }

            val oldPosition = transactionType.indexOf(oldTransactionType)

            notifyItemChanged(oldPosition)
        },
        updateListener = { newPosition -> notifyItemChanged(newPosition)},
        clickListener = onTransactionTypeClicked
    )
}

Viewholder :

fun render(
    data: TransactionType,
    dataIndex: Int,
    adapterListener: (() -> Unit),
    updateListener: ((Int) -> Unit),
    clickListener: ((TransactionType) -> Unit)?
) {
    val onClickListener: View.OnClickListener = View.OnClickListener {

        adapterListener.invoke()

        data.isItemSelected = true

        updateListener.invoke(dataIndex)

        clickListener?.invoke(data)
    }

    binding.vhTransactionType.setOnClickListener(onClickListener)
    binding.rbTransactionType.setOnClickListener(onClickListener)

    binding.rbTransactionType.isChecked = data.isItemSelected
}

Any solution would be great, thanks a lot!

Answer 1

You need to clear the selection on the radio button before setting its correct value.

I will use a java example to explain the concept.

holder.radioGroup.clearCheck()

This way, the RadioGroup clears its selection, ready to receive an input that will trigger the correct RadioButton as checked.

But you need to be aware that this might call your onCheckedChanged listeners and could bring unexpected outcomes. But there is a work around for the resulting problem.

// Nullify listener
holder.radioGroup.setOnCheckedChangeListener(null);

// Clear selection
holder.radioGroup.clearCheck();

// Reset listener after selection has been cleared
holder.radioGroup.setOnCheckedChangeListener(checkedChangeListener);

You can do this in kotlin