how to instantiate ViewModel In AndroidX?

Question

I want to initialize ViewModel in Activity using androidx library

I have tried what documentation says but it is not working. the ".of" is not resolved.

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import androidx.databinding.DataBindingUtil
import androidx.lifecycle.ViewModelProvider
import com.example.myapplication.databinding.ActivityMainBinding`

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        val binding: ActivityMainBinding = DataBindingUtil.setContentView(
            this, R.layout.activity_main)
        binding.setLifecycleOwner(this)

        var model = ViewModelProvider.of(this).get(SheduleViewModel::class.java)

    }
}

of is not resolved, maybe there are another way to do it in androidx

Answer 1

Updated answer:

Things changed a little bit, as the previously needed dependency - ViewModelProviders - got deprecated (see the old answer for details). You can now use the ViewModelProvider constructor directly.

So, in this case, the answer would be:

private val viewModel = ViewModelProvider(this).get(SheduleViewModel::class.java)

Note that, however, if you're instantiating a ViewModel in a Fragment, you can add the androidx.fragment:fragment-ktx:$Version dependency and then make use of property delegation:

private val viewModel: SheduleViewModel by viewModels()

Which internally will use ViewModelProvider and scope your ViewModel to your Fragment. It's just a more concise way of writing the same thing.

Both the ViewModelProvider constructor and by viewModels() also accept a factory as a parameter (useful for injecting your ViewModel):

private val viewModel = 
    ViewModelProvider(this, viewModelFactory).get(SheduleViewModel::class.java)

and

private val viewModel: SheduleViewModel by viewModels { viewModelFactory }

Use the one that best suits you.

Old answer:

Add the androidx.lifecycle:lifecycle-extensions:$lifecycleExtensionsVersion dependency in order to import ViewModelProviders.