Kotlin: How Can I access my Array in my Adapter Function?

Issue

I am creating an app where the user can add items to their cart. Once the user is done, they can click Proceed To Cart which will then open up a new activity showing them the contents of their cart. The contents of the cart are stored in an array and I am passing the array to my second activity using an intent. But cannot access it my MyCustomAdapterClass.

Here is my code:

import android.content.Context
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.BaseAdapter
import android.widget.ListView
import android.widget.TextView
import java.text.FieldPosition

class Cart : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_cart)

        val intent = intent
        val listview = findViewById<ListView>(R.id.CartItems)
        listview.adapter = MyCustomAdapter(this)



    }

    private inner class MyCustomAdapter(context: Context): BaseAdapter(){
         private val mContext: Context
         val listOfCartItems = intent.getStringArrayListExtra("CuriseCart")
         val sizeOfCart = listOfCartItems?.size

        init {
             mContext = context
         }

        override fun getCount(): Int {
            return sizeOfCart!!
        }

        override fun getItemId(position: Int): Long {
            return position.toLong()
        }

        override fun getItem(position: Int): Any {
            return "Testing"
        }

        override fun getView(position: Int, convertView: View?, viewGroup: ViewGroup?): View {
            val layoutInflater = LayoutInflater.from(mContext)
            val rowFormat = layoutInflater.inflate(R.layout.listview_custom, viewGroup, false)

            println("Cart Items"+listOfCartItems)
            println("Size of Cart"+sizeOfCart)

            val cruiseTitle = rowFormat.findViewById<TextView>(R.id.cruiseTitle)
            cruiseTitle.text = listOfCartItems?.get(sizeOfCart!!)

            val durationLabel = rowFormat.findViewById<TextView>(R.id.durationLabel)
            val numOfTravelers = rowFormat.findViewById<TextView>(R.id.numOfTravelers)
            val costOfCruise = rowFormat.findViewById<TextView>(R.id.costOfCruise)



            return rowFormat
        }


    }
}

I am trying to print whatever is in my array in the listview. I did some testing to see if the values were being passed by printing to console and it is correctly passing the values.

Solution

You are not passing your ArrayList to your MyCustomAdapter.

You can either make your MyCustomAdapter class an inner class or you can change the constructor of MyCustomAdapter to accept your ArrayList

For making MyCustomeAdapter an inner class, just add inner keyword to your class.

 private inner class MyCustomAdapter(context: Context): BaseAdapter() {
     //use listOfCardItem in the class
     }

Or Add listOfCardItems to your MyCustomeAdapter constructor

 private class MyCustomAdapter(context: Context, listOfCartItems: ArrayList<String>): BaseAdapter() {
     //use listOfCardItem in the class
     }

You don't have to manually define a property in the class and initialize it with the received value in the primary constructor.

You can define your properties inside the primary constructor with val keyword for avoiding the manual initialization of them inside the init block.

private class MyCustomAdapter(val context: Context, val listOfCartItems: ArrayList<String>)

Answered By - Praveen