Adding RecyclerView Item Total

Question

In my Project, I have a recyclerview which contains adapter and fragment class. Everything is working as expected and I am trying to sum a particular column value and display it in a text field. I tried below total method but its not working. Any help is appreciated.

Language Used

Kotlin

Code Used

Adapter Class

   override fun onBindViewHolder(holder: ViewHolder, position: Int)
    {
        holder.bindcar(list[position],fragment)

    }
    fun bindcar(Test: TestCart?, fragment: TestFragment)=with(carView)
        {
            TestName.text=Test?.carName
            TestQuantity.text= Test?.carQuantity.toString()
            TestPrice.text= Test?.carPrice!!.toString()
        }

Fragment

for (c in carList!!.iterator())
    {
            val car=TestCart()

            //var carPrice=0
            car.carName=c.carName
            car.carQuantity=c.carQuantity
            car.carPrice=c.carPrice
           // car.carPrice= c.carPrice!! +Price
            carListcars!!.add(car)
    }
    adapter!!.notifyDataSetChanged()
    }

Expectation

Total CarPrice in the Recycler View.

Answer 1

you can use sumBy method of Kotlin List to do that.

Inside your fragment class add below code

for (c in carList!!.iterator())
  {
      val car=TestCart()

            //var carPrice=0
            car.carName=c.carName
            car.carQuantity=c.carQuantity
            car.carPrice=c.carPrice
           // car.carPrice= c.carPrice!! +Price
            carListcars!!.add(car)
    }

    adapter!!.notifyDataSetChanged()

    // sumby code 
    var totalAmount: Int = carListcars.sumBy{ it.carPrice }

    // setting your textView
    TestPrice.text = totalAmount.toString()


    }