Cannot resolve symbol ViewModelProviders on AppCompatActivity

Question

Hey I'm trying to get my ViewModel working, but no luck so far. Android Studio shows error Cannot resolve symbol 'ViewModelProviders'.

Every other question I found on this topic was correcting extends Activity to extends AppCompatActivity, but I am extending the right one. Not sure what I'm missing...
My code is based on This YouTube video

MainActivity.java

public class MainActivity extends AppCompatActivity implements
    TileAdapter.TileAdapterOnClickHandler {


private BaseViewModel viewModel;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //set Toolbar
    Toolbar myToolbar = findViewById(R.id.toolbar);
    setSupportActionBar(myToolbar);


    //initialize viewModel
    viewModel = ViewModelProviders.of(this).get(BaseViewModel.class);

BaseViewModel.java

public class BaseViewModel extends ViewModel {

private Movie[] mMovie;

public void init (Movie[] movies){
    this.mMovie = movies;
}

public Movie[] getMovie() {
    return mMovie;
}

Answer 1

I didn't have both dependencies in my build, hence the problem.

implementation "android.arch.lifecycle:extensions:1.1.0"
implementation "android.arch.lifecycle:viewmodel:1.1.0"

Thanks @Muthukrishnan Rajendran

Answer 2

If you are using androidx you need this:

implementation 'androidx.lifecycle:lifecycle-extensions:2.1.0'

Answer 3

android.arch.lifecycle:extensions is deprecated use

def lifecycle_version = "2.2.0"
implementation "androidx.lifecycle:lifecycle-viewmodel:$lifecycle_version"
implementation "androidx.lifecycle:lifecycle-livedata:$lifecycle_version"

Create instance of viewmodel like this:

Java

Yourclass obj = new ViewModelProvider(context).get(ClassViewModel.class);

Kotlin

var obj = ViewModelProvider(context).get(ClassViewModel::class.java)

Answer 4

If you are using compiled sdk version 28 or higher you only need to add single dependecy to get ViewModel and LiveData

dependencies {
    //...
    def lifecycle_version = "1.1.1"

    // ViewModel and LiveData
    implementation "android.arch.lifecycle:extensions:$lifecycle_version"
}

Answer 5

In my case (Android Studio 3.6.3 ~ 4.1.2), in AppCompatActivity to successfully do:

MyViewModel myViewModel = new ViewModelProvider(this).get(MyViewModel.class);

it requires both of these:

implementation 'androidx.appcompat:appcompat:1.1.0'
implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'

(alone with lifecycle-extentions is not sufficient)

Update

It seems that you have no longer to include the gradle implementation line ('androidx.lifecycle:lifecycle-extensions:2.2.0') to instantiate ViewModelProvider.

Answer 6

you should add library in your project's build.gradle

def lifecycle_version = "2.0.0"

// ViewModel and LiveData
implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_version"

Answer 7

I solve this problem from Android official documentation. Add below to build.grale

def lifecycle_version = "2.0.0"
// ViewModel and LiveData
implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_version"

Answer 8

In implementation "androidx.lifecycle:lifecycle-extensions:2.2.0" and up ViewModelProviders is deprecated,use

viewModel = ViewModelProvider(this).get(BaseViewModel.class);

or in Kotlin

viewModel = ViewModelProvider(this).get(BaseViewModel::class.java);

instead of

viewModel = ViewModelProviders.of(this).get(BaseViewModel.class);

Answer 9

In the build.gradle file, add these lines in the dependencies block

dependencies {
...
def lifecycle_version = "1.1.1"
// ViewModel and LiveData
implementation "android.arch.lifecycle:extensions:$lifecycle_version"
//if not using java 8,use the following line
annotationProcessor "android.arch.lifecycle:compiler:$lifecycle_version"
//if using java 8,ignore above line and add the following line
implementation "android.arch.lifecycle:common-java8:$lifecycle_version"
...
}

Answer 10

-'ViewModelProviders' is deprecated now

• Now alternative

• In java

viewModel = ViewModelProvider(this).get(BaseViewModel.class);

• In kotlin

var viewModel = ViewModelProvider(this).get(BaseViewModel::class.java)

Refs - https://developer.android.com/reference/androidx/lifecycle/ViewModelProviders

Answer 11

Use androix libraries

Change

implementation 'com.android.support:appcompat-v7:28.0.0'

to

implementation 'androidx.appcompat:appcompat:1.1.0-alpha03'

You can use

Refactor>Migrate to AndroidX

Answer 12

Works fine in my app(java) before

loginViewModel = ViewModelProviders.of(this, new LoginViewModelFactory())
                .get(LoginViewModel.class);

changes to

loginViewModel = new ViewModelProvider(this,new LoginViewModelFactory()).get(LoginViewModel.class);

hope it could help

Answer 13

In My Case, I am facing below issue i.e:

** cannot access androidx.lifecycle.has a default viewmodelprovider factory which is a subclass of your class Name, check your module classpath check your model conflicting dependencies **

I added below dependencies in my project build.gradle.

def lifecycle_version = "2.2.0"

implementation "androidx.lifecycle:lifecycle-viewmodel:$lifecycle_version"

implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_version"

Then I create my class in a module project and I'm facing this issue, then I add these libraries in module build.gradle file and the issue is resolved.

Answer 14

I had the same problem. None of the other solutions helped me.

I realized that I was using import androidx.lifecycle.ViewModelProvider; instead of import androidx.lifecycle.ViewModelProviders;.

So make sure you are using import androidx.lifecycle.ViewModelProviders;. That is ViewModelProviders with an s.