如何在活动之间共享 ViewModelProvider.Factory 实例

Question

I have a ViewModelProvider.Factory instance that is responsible for instantiating ViewModels and injecting repositories into the ViewModels.

This works well for Fragments as I simply supply my custom Fragment factory with the ViewModel factory:

this.supportFragmentManager.fragmentFactory = MyFragmentFactory(myViewModelFactory)

The fragment factory injects the ViewModel factory into the Fragments when instantiating them. The Fragments can then access the ViewModels through:

mapViewModel = ViewModelProvider(this, myViewModelFactory).get(MyViewModel::class.java) 

However, I want to launch a new Activity that will also require access to the same ViewModel factory.

Can I share my ViewModelProvider.Factory instance across Activities without using a global variable?

Answer 1

Use the Common class concept. Make a common class and a public static variable of your required Datatype and store values there and when you need to access just use Common.YOUR_VARIABLE_NAME;

Public class Common{
  public static REQUIRED_DATATYPE variableName;
  }

store the value which you need to access in another activity as
Common.variableName = YOUR_VALUE; and when you need to use just type Common.variableName

Feel free to ask if something is unclear.