How do I replace a fragment in another fragment?
Use replace() to replace an existing fragment in a container with an instance of a new fragment class that you provide. Calling replace() is equivalent to calling remove() with a fragment in a container and adding a new fragment to that same container. transaction. commit();
What is fragment describe fragment lifecycle and how it relates to activity lifecycle?
A fragment has its own layout and its own behaviour with its own life cycle callbacks. You can add or remove fragments in an activity while the activity is running. You can combine multiple fragments in a single activity to build a multi-pane UI. A fragment can be used in multiple activities.
Can ViewModel observe LiveData?
Update LiveData objects Usually MutableLiveData is used in the ViewModel and then the ViewModel only exposes immutable LiveData objects to the observers.
How do you instantiate a ViewModel?
There are four main steps in creating and using a ViewModel :
- Add dependencies in your app-level build.
- Separate out all your data from your activity by creating a class that extends the ViewModel .
- Create a ViewModel instance in your activity to use it.
- Set up communications between your ViewModel and your View layer.
What is the difference between ViewModel and AndroidViewModel?
The difference between the ViewModel and the AndroidViewModel class is that the later one provides you with an application context, which you need to provide when you create a view model of type AndroidViewModel.
Can the view model have a constructor with arguments?
With the new android. One problem with the default ViewModel is the constructor takes zero parameters. If you want to make it takes parameters, you need to make a new FactoryClass for each view model.
What is the difference between ViewModelProvider and ViewModelProviders?
Creates a ViewModelProvider , which retains ViewModels while a scope of given fragment is alive. More detailed explanation is in ViewModel . It uses ViewModelProvider. AndroidViewModelFactory to instantiate new ViewModels….
|ViewModelProvider||a ViewModelProvider instance|
What is ViewModelProvider for?
On the other hand, ViewModelProvider (belongs to Maven artifact android. arch. lifecycle:viewmodel) is class that provides ViewModels for a scope. So it’s default ViewModelProvider for an Activity or a Fragment can be obtained from ViewModelProviders class.
What is ViewModel provider in Android?
android.arch.lifecycle.ViewModelProvider. An utility class that provides ViewModels for a scope. Default ViewModelProvider for an Activity or a Fragment can be obtained from ViewModelProviders class.
What is the use of ViewModel factory in Android?
You use the ViewModel class to store and manage UI-related data in a lifecycle-conscious way. The ViewModel class allows data to survive device-configuration changes such as screen rotations and changes to keyboard availability.
What is ViewModelProvider Newinstancefactory?
ViewModelProvider.AndroidViewModelFactory. ViewModelProvider. Factory which may create AndroidViewModel and ViewModel , which have an empty constructor. Known indirect subclasses. ViewModelProviders.DefaultFactory.
What is the use of ViewModelProvider factory?
ViewModelProvider. Factory that can create ViewModels accessing and contributing to a saved state via SavedStateHandle received in a constructor. ViewModelProvider. Factory which may create AndroidViewModel and ViewModel , which have an empty constructor.