Start activity from button.setOnClickListener which lies in my RecyclerView-CodePudding

I want an activity/class to run on a Button click. The Button is inside my RecyclerView. I first had the code in my MainActivity with:

btnComplete.setOnClickListener {
            startActivity(Intent(this@MainActivity, DelComplete::class.java))}

This code was in my onCreate of my MainActivity. How ever on running the code I found the error:

 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

My first thought was that it could not reach the Button since it was in the RecyclerView. So I tried to put the code in my RecyclerView. But I read that it is not a good idea to put it in you RecyclerView and I dont know what to do with the Context as it keeps throwing errors.

RecyclerView:

     txtbutton1.setOnClickListener {
                    confirmdel()
                    modal.tvdone = "Delivered"
                    Log.e("Clicked", "Successful delivery")
                    //this is where I add code to export data through api
                    modal.state = DataState.Success
                    Status = 1
                    notifyDataSetChanged()}

    private fun confirmdel() {
        startActivity(Intent(this, DelComplete::class.java))}

It might be as simple as filling in the Context but I am unsure what the Context must be to test that theory.

Recyclerview- table_list_item

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"

    android:layout_height="wrap_content"
    android:orientation="horizontal">

    <TextView
        android:id="@ id/txtWOrder"
        android:layout_width="160dp"
        android:layout_height="match_parent"
        android:layout_gravity="top"
        android:background="@drawable/table_content_cell_bg"
        android:text="@string/worder"
        android:textSize="18sp"
        tools:ignore="TextContrastCheck" />

    <TextView
        android:id="@ id/txtDElNote"
        android:layout_width="190dp"
        android:layout_height="match_parent"
        android:layout_gravity="top"
        android:background="@drawable/table_content_cell_bg"
        android:text="@string/delnote"
        android:textSize="18sp"
        tools:ignore="TextContrastCheck" />

    <TextView
        android:id="@ id/txtCompany"
        android:layout_width="190dp"
        android:layout_height="match_parent"
        android:layout_gravity="top"
        android:background="@drawable/table_content_cell_bg"
        android:text="@string/company"
        android:textSize="18sp"
        tools:ignore="TextContrastCheck" />

    <Button
        android:id="@ id/btnComplete"
        android:layout_width="250dp"
        android:layout_height="match_parent"
        android:layout_gravity="top"
        android:background="@drawable/table_header_cell_bg"
        android:drawableTint="#70D5C8"
        android:text="@string/button1"
        android:textSize="18sp" />

    <Button
        android:id="@ id/btnException"
        android:layout_width="250dp"
        android:layout_height="match_parent"
        android:layout_gravity="top"
        android:background="@drawable/table_content_cell_bg"
        android:text="@string/button2"
        android:textSize="18sp" />

    <TextView
        android:id="@ id/txttvdone"
        android:layout_width="50dp"
        android:layout_height="match_parent"
        android:background="@drawable/table_content_cell_bg"
        android:foregroundGravity="center_horizontal"
        android:text=""
        android:textAlignment="center"
        android:textSize="24sp"
        android:textStyle="bold" />

    <TextView
        android:id="@ id/txtWeight"
        android:layout_width="190dp"
        android:layout_height="match_parent"
        android:layout_gravity="top"
        android:background="@drawable/table_content_cell_bg"
        android:text="@string/weight"
        android:textSize="18sp"
        tools:ignore="TextContrastCheck" />
</LinearLayout>

The reason why I have a Button in my RecyclerView is on every entry a driver should be able to give feedback on a delivery. Every entry is a different order. Did I go the wrong way of doing this?

My Button does the following:

   txtbutton1.setOnClickListener {

                    confirmdel()
                    modal.tvdone = "Delivered"
                    Log.e("Clicked", "Successful delivery")
                    //this is where I add code to export data through api
                    modal.state = DataState.Success
                    Status = 1
                    notifyDataSetChanged()
                }

It does that with no problem. Now however I want to add an AlertDialog and update data in my DB with the setOnClickListener. Will this be possible from within my adapter?

CodePudding user response：

You shouldn't put a button inside of your RecyclerView, unless you are referring to a button as the item itself. RecyclerViews are used to render as much as items as you have in your data source, instead of hardcoding them, so I think you want to handle the click on a single item and navigate to another Activity with the data of that item.

You can do that by following these steps. This is a codelab made by Google and explains how to handle the item click.

In addition, you should do those too, in order to better understanding.RecyclerViews

CodePudding user response：

You can use the context like this :

class Adapter(private val context: Context, private val myList: List<String>) :
RecyclerView.Adapter<Adapter.ViewHolder>()

And pass the context where required like this

    private fun confirmdel() {
    startActivity(Intent(context, DelComplete::class.java))}