what I want to achieve is to send data from custom recycle view adapter to activity when button is clicked. More specifically I want to send over an integer value.

RecycleAdapter code

class RecyclerAdapter(ingredientsList: MutableList<String>) : RecyclerView.Adapter<RecyclerAdapter.ViewHolder>()
{

private var ingredients : MutableList<String> = ingredientsList

private var testInt : Int = 0
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
    val v = LayoutInflater.from(parent.context).inflate(R.layout.lv_view_item,parent,false)
    return ViewHolder(v,)
}

override fun onBindViewHolder(holder: ViewHolder, position: Int) {
    holder.pName.text = ingredients[position]

    var ingrCount : TextView = holder.itemView.findViewById(R.id.ingredientCount)
    var decrementIngr : Button = holder.itemView.findViewById(R.id.deleteIngeredient)

    var incrementIngr : Button = holder.itemView.findViewById(R.id.addIngredient)
    incrementIngr.setOnClickListener{
        val count = Integer.parseInt(ingrCount.text.toString())   1
        ingrCount.text = "$count"
        testInt = count

        Log.w("w", testInt.toString())

    }
    decrementIngr.setOnClickListener{
        val count = Integer.parseInt(ingrCount.text.toString()) - 1
        ingrCount.text = "$count"
        testInt = count

        Log.w("w", testInt.toString())
    }
}

override fun getItemCount(): Int {
    return ingredients.size
}

class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView)
{
    var pName : TextView = itemView.findViewById(R.id.ingredientName)

    init {

        itemView.setOnClickListener{
            val position : Int = adapterPosition
        }
    }

}

}

And in my activity I want to get testInt variable when I click a button.

btn_create_order.setOnClickListener{
    //somehow get the data
}

Thanks

CodePudding user response：

First of all create an interface like OnItemClickValue:

interface OnItemClickValue {
    fun onValueChange(value: Int)
}

and pass through Adapter and call onValueChange() method from onClick:

class RecyclerAdapter(ingredientsList: MutableList<String>, val onItemClickValue:OnItemClickValue) : RecyclerView.Adapter<RecyclerAdapter.ViewHolder>()
{

    private var ingredients : MutableList<String> = ingredientsList

    private var testInt : Int = 0
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        val v = LayoutInflater.from(parent.context).inflate(R.layout.lv_view_item,parent,false)
        return ViewHolder(v,)
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        holder.pName.text = ingredients[position]

        var ingrCount : TextView = holder.itemView.findViewById(R.id.ingredientCount)
        var decrementIngr : Button = holder.itemView.findViewById(R.id.deleteIngeredient)

        var incrementIngr : Button = holder.itemView.findViewById(R.id.addIngredient)
        incrementIngr.setOnClickListener{
            val count = Integer.parseInt(ingrCount.text.toString())   1
            ingrCount.text = "$count"
            testInt = count
            onItemClickValue.onValueChange(testInt)
            Log.w("w", testInt.toString())

        }
        decrementIngr.setOnClickListener{
            val count = Integer.parseInt(ingrCount.text.toString()) - 1
            ingrCount.text = "$count"
            testInt = count
            onItemClickValue.onValueChange(testInt)
            Log.w("w", testInt.toString())
        }
    }

    override fun getItemCount(): Int {
        return ingredients.size
    }

    class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView)
    {
        var pName : TextView = itemView.findViewById(R.id.ingredientName)

        init {

            itemView.setOnClickListener{
                val position : Int = adapterPosition
            }
        }

    }

}

Implement OnItemClickValue interface on Activity:

class MainActivity: AppCompatActivity(), OnItemClickValue{
    var testInt:Int = 0
    override fun onValueChange(value: Int) {
        testInt = value
    }

    btn_create_order.setOnClickListener{
        //You will get testInt from here

        Log.d("TAG", "testInt $testInt")
    }
}