How to send multiple selected utem from recyclerview to another activity

I have list of contacts in where i select multiple items and pass to another activity ,In Recyclerview after selecting multiple items how do i pass it to another activity here is my Adapter class


    override fun onBindViewHolder(holder: ContactViewHolder, position: Int) {
        val item = contact[position]
        holder.name.text = item.name
        holder.number.text = item.number
        holder.linlay.setOnLongClickListener{
            selectItem(holder,item,position)

            true
        }
        holder.linlay.setOnClickListener{
            if(itemSelected.contains(position)){
              itemSelected.remove(position)

                holder.linlay.setBackgroundColor(Color.DKGRAY)
                item.isSelect = false
                if(itemSelected.isEmpty()){
                    isEnable=false
                }
            }
            else if(isEnable){
                selectItem(holder,item,position)
            }
        }
    }

    private fun selectItem(holder: ContactAdapter.ContactViewHolder, item: ContactModel, position: Int) {
        isEnable = true
        itemSelected.add(position)
        item.isSelect = true
        holder.linlay.setBackgroundColor(Color.YELLOW)
    }

Where button for going to another activity is instead of recyclerview is in mainActivity class

class Mainactivity : AppComapctActivity(){

ovveride fun onCreate(savedInstanceState: Bundle?){
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)

val btn_send = findViewById<Button>(R.id.btn_send)
btn_send.setOnClickListner{
val intent = Intent(this,HomeActivity::class.java)
startActivity(intent)
}
}

CodePudding user response：

When you select a contact in your selectItem method you should create a MutableList of contacts like MutableList inside of this list you will store the selected contacts previously, since you can remove/update the selected contact list you should be using MutableList after you select all your contacts you should have a button to go to the next screen. There you should only send the MutableList of ContactModel

Let me do some pseudocode for you

private fun selectItem(holder: ContactAdapter.ContactViewHolder, item: ContactModel, position: Int) {
        isEnable = true
        itemSelected.add(position)
        item.isSelect = true
        holder.linlay.setBackgroundColor(Color.YELLOW)
        if(item.isSelect)
        myMutableContactList.add(item)
        else
        myMutableContactList.remove(item)
    }

remember to create first the mutableList like

val myMutableContactList = mutableListOf<ContactModel>()

and then if you have a button to go to the next screen just send this list

When you press the button and go to the next fragment/activity a good practice will be to convert this mutablelist to a list since it will not change after beign send.

You can do it by simple using toList() on your mutableList