How to use view Model in Asp.Net Core MVC

Not sure about your question as ViewModels are custom classes and you can create it like any other classes. You might be looking for use case for ViewModel.

 

For example you have a Model with name "Employee", which is directly bind with Database layer. This Model has 2 separate properties "FirstName" and "LastName". Your UI would display name as a single  clubbed value i.e. "LastName, FirstName". So you need to format your Model in accordance to the UI display even without impacting your Model->Database binding. This is the case most VewModels come in to picture.

You create a separate  ViewModel name "EmployeeViewModel" with a single  property "Name".

 

Whenever you have your Model values from database, pass the Model object to a Mapper class where ViewModel values will be mapped from your Model i.e. like below pseudocode.

 

 EmployeeViewModel.Name = Employee.LastName + " ," + Employee.FirstName

 

 

Now most important thing is that you only pass ViewModel to your UI, not actual Model. UI should not aware of backend Model.  Here you achieve a goal of using same Model for different UI with the help of ViewModel. You also decoupling the database-bound Model from UI using ViewModel