Unable to resolve service for type 'Microsoft.AspNetCore.Identity.UserManager` while attempting to activate 'AuthController'

Question

I\'m getting this error in Login Controller.

InvalidOperationException: Unable to resolve service for type \'Microsoft.AspNetCore.Identity.UserManager

Answer 1

Just to be clear about the answer:

If you use the class ApplicationUser in startup.cs: services.AddIdentity()

then you must use the same class in your controller when injecting it:

public AccountController(UserManager userManager)

If you use some other class such as:

public AccountController(UserManager userManager)

then you will get this error:

InvalidOperationException: Unable to resolve service for type 'Microsoft.AspNetCore.Identity.UserManager`1[IdentityUser]'

because you used ApplicationUser in startup, not IdentityUser so this type is not registered with the injection system.