Why a viewmodel factory is needed in Android?

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We can not create ViewModel on our own. We need ViewModelProviders utility provided by Android to create ViewModels.

But ViewModelProviders can only instantiate ViewModels with no arg constructor.

So if I have a ViewModel with multiple arguments, then I need to use a Factory that I can pass to ViewModelProviders to use when an instance of MyViewModel is required.

For example – 

public class MyViewModel extends ViewModel {
    private final MyRepo myrepo;
    public MyViewModel(MyRepo myrepo) {
         this.myrepo = myrepo;
    }
}

To instantiate this ViewModel, I need to have a factory which ViewModelProviders can use to create its instance.

ViewModelProviders Utility can not create instance of a ViewModel with argument constructor because it does not know how and what objects to pass in the constructor.

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