Using viewModels()

Android Programming (5th Edition) 9. Fragments
1

Hi everyone, the problem is the following, in listing 10.3, when I create a CrimeListFragment class and associate it with a CrimeListViewModel, I cannot initialize it using viewModels() - this is marked in red. But when I create CrimeListFragment as a subclass, for example, FragmentActivity(), everything works out.

package com.example.criminalintent

import android.os.Bundle
import android.util.Log
import androidx.fragment.app.Fragment
import androidx.activity.viewModels

private const val TAG = “CrimeListFragment”
class CrimeListFragment: Fragment(){
private val crimeListViewModel:CrimeListViewModel by viewModels() // Unresolved reference. //None of the following candidates is applicable because of receiver type mismatch:

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    Log.d(TAG, "Total crimes: ${crimeListViewModel.crimes.size}")
}}

How to fix it?

3

I’m guessing it’s because you’re importing activity.viewmodels but you want it for a fragment, change this line :

import androidx.activity.viewModels
to :
import androidx.fragment.app.viewModels