Multiplying 2 numbers without buttons in Kotlin TextWatcher

Question

My aim is to automatically display the numbers entered by the user in the textView below using 2 edittext as shown below. How can I do this?Because this is crush. I would appreciate it if you explain in detail. Thanks in advance.

 items3=pronumber.text.toString() // Edittext
    items4=proprice.text.toString()// Edittext


    pronumber.addTextChangedListener ( object:TextWatcher{
        override fun afterTextChanged(p0: Editable?) {

        }

        override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            TODO("Not yet implemented")
        }

        override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            totalprice.text= "Toplam Tutar : "+(items3.toInt()*items4.toInt()).toString() +" TL"  //TextView

        }


    } )

    proprice.addTextChangedListener ( object:TextWatcher{
        override fun afterTextChanged(p0: Editable?) {

        }

        override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            TODO("Not yet implemented")
        }

        override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            totalprice.text= "Toplam Tutar : "+(items3.toInt()*items4.toInt()).toString() +" TL"  //TextView

        }


    } )


    items5=totalprice.text.toString()

Answer 1

You should change your code like

        items3=pronumber.text.toString() // Edittext
        items4=proprice.text.toString()// Edittext


        pronumber.addTextChangedListener ( object:TextWatcher{
            override fun afterTextChanged(p0: Editable?) {

            }

            override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            }

            override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
                val first = pronumber.text.toString()
                val second = proprice.text.toString()
                totalprice.text =  if (first.isBlank() || second.isBlank()){
                    "Toplam Tutar : 0 TL"
                } else {
                    "Toplam Tutar : ${first.toInt().times(second.toInt())} TL"
                }

            }


        } )

        proprice.addTextChangedListener ( object:TextWatcher{
            override fun afterTextChanged(p0: Editable?) {

            }

            override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            }

            override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
                totalprice.text =  if (first.isBlank() || second.isBlank()){
                    "Toplam Tutar : 0 TL"
                } else {
                    "Toplam Tutar : ${first.toInt().times(second.toInt())} TL"
                }
            }


        } )


        items5=totalprice.text.toString()