在新课程中与Kotlin一起使用recyclerView

Question

have created a recyclerView with Kotlin on mainActivity.

it works just fine.

I would like now to transfer my code to a new class Call that class from MainActivity and activate the recyclerView that way.

Called that class at mainActivity, but apperantly that is not enough…

var newClass: NewClass = NewClass()

How do I call a class with a recyclerView or how to activate it ?

Added the call for newClass. Would like to remove all of these lines.

Thank you

This is my code at onCreate:

enter code here

var newClass: NewClass = NewClass()


rowsList = ArrayList<RowFromModel>()
layoutManager = LinearLayoutManager(this)
adapter = RowListAdapter(rowsList!!, this)

rowsListRv.layoutManager = layoutManager
rowsListRv.adapter = adapter

//load data
var model = TableViewModel()

var dataFromModel: ArrayList<String> = model.getData()
for (i in 0..dataFromModel.size - 1) {
    val rowFromModel = RowFromModel()
    rowFromModel.row = dataFromModel.get(i)
    rowsList!!.add(rowFromModel)
}

adapter!!.notifyDataSetChanged()
enter code here

Answer 1

The problem is that NewClass need some way to know the recyclerView and the Context (or Activity) to work on, so they should be passed to the class. You can do so by doing the following

class NewClass (val recyclerView: RecyclerView, val context: Context) {

    val rowsList = ArrayList<RowFromModel>() 
    val layoutManager = LinearLayoutManager(context) 
    val adapter = RowListAdapter(rowsList, context)

    // load data
    var model = TableViewModel()

    var dataFromModel: ArrayList<String> = model.data 
    val rowFromModel = RowFromModel()

    init {
        // this will be called after the constructor is called
        recyclerView.layoutManager = layoutManager 
        recyclerView.adapter = adapter 

        for (i in 0..dataFromModel.size - 1) {
            val rowFromModel = RowFromModel()
            rowFromModel.row = dataFromModel[i]
            rowsList.add(rowFromModel)
        }

        adapter.notifyDataSetChanged()
    }
}

and then in your MainActivity 's onCreate() , you can do the following

var newClass: NewClass = NewClass(rowsListRv, this)

Hope this helps!