Q:

Recyclerview Adapter onCreateViewHolder method LinearLayout cannot be cast to TextView

So I'm just trying to set up a simple Recyclerview to display strings from an array. Here's the adapter that I have set up:
package com.example.workoutapp1;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.ViewGroup;
import android.widget.TextView;

import androidx.recyclerview.widget.RecyclerView;

public class WorkoutActivityAdapter extends RecyclerView.Adapter<WorkoutActivityAdapter.MyViewHolder> {
    private String[] mDataset;

    // Provide a reference to the views for each data item
    // Complex data items may need more than one view per item, and
    // you provide access to all the views for a data item in a view holder
    public static class MyViewHolder extends RecyclerView.ViewHolder {
        public TextView textView;
        public MyViewHolder (TextView v) {
            super(v);
            textView = (TextView) v.findViewById(R.id.workout_text_view);
        }
    }

    // Provide a suitable constructor (depends on the kind of dataset)
    public WorkoutActivityAdapter(String[] myDataset) {
        mDataset = myDataset;
    }

    // Create new views (invoked by the layout manager)
    @Override
    public WorkoutActivityAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        Context context = parent.getContext();
        LayoutInflater inflater = LayoutInflater.from(context);

        // Inflate the custom layout
        TextView contactView = (TextView) inflater.inflate(R.layout.workout_item, parent, false);

        // Return a new holder instance
        WorkoutActivityAdapter.MyViewHolder viewHolder = new WorkoutActivityAdapter.MyViewHolder(contactView);
        return viewHolder;
    }

    // Replace the contents of a view (invoked by the layout manager)
    @Override
    public void onBindViewHolder(MyViewHolder holder, int position) {
        // - get element from your dataset at this position
        // - replace the contents of the view with that element\
        holder.textView.setText(mDataset[position]);

    }

    // Return the size of your dataset (invoked by the layout manager)
    @Override
    public int getItemCount() {
        return mDataset.length;
    }
}

workout_item.xml is a simple linearlayout as follows:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingTop="10dp"
    android:paddingBottom="10dp" >

    <TextView
        android:id="@+id/workout_text_view"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1" />

</LinearLayout>

Every time I run this, the app crashes, as there is a fatal exception where I'm trying to Inflate the custom layout:

"java.lang.ClassCastException: android.widget.LinearLayout cannot be cast to android.widget.TextView"

I'm having trouble understanding what's going on, as I'm simply following tutorials online.
If anybody could help me out, that would be greatly appreciated.

A:

When you do inflater.inflate(R.layout.workout_item, parent, false), you are inflating the full layout of your XML file. The topmost element of that XML file is a LinearLayout, so the returned inflated layout is a LinearLayout, not a TextView.
You have two options:

Remove the LinearLayout entirely.

This would mean your layout would only contain your single TextView, which would make your casting succeed.
<?xml version="1.0" encoding="utf-8"?>
<TextView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/workout_text_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingTop="10dp"
    android:paddingBottom="10dp"
    />

Update your ViewHolder to take the full layout.

Here you'd update your WorkoutActivityAdapter.MyViewHolder to take the full layout and use view.findViewById(R.id.workout_text_view) to get the TextView out of your layout. This would be appropriate if you had more than one view in your layout.

