EntityType' is a variable but is used like a type when use the Reflection

Question

i need to register all entity in DbContext .

i create a extention for register automatic all Entity with Reflection :

  public static void RegisterAllEntity<BaseType>(this DbModelBuilder builder, params Assembly[] assmblies)
    {
        IEnumerable<Type> types = assmblies.SelectMany(x => x.GetExportedTypes())
            .Where(x => x.IsClass && !x.IsAbstract && x.IsPublic && typeof(BaseType).IsAssignableFrom(x));

        foreach (Type EntityType in types)
            builder.Entity<EntityType>();
    }

but it show me this error :

EntityType' is a variable but is used like a type

in this line :

    foreach (Type EntityType in types)
            builder.Entity<EntityType>();

whats the problem ? how can i solve this problem ???

You're mixing run time `Type` objects with compile time Typing, you need an overload of `Entity` which accepts a Type _object_. — thisextendsthat, Apr 02 '19 at 10:21
@thisextendsthat Please guide me further. How should I do this? — mr-dortaj, Apr 02 '19 at 10:23
You can find something here https://stackoverflow.com/questions/44207451/x-is-a-variable-but-used-like-a-type-when-trying-to-cast — , Apr 02 '19 at 10:23

score 2 · Accepted Answer · answered Apr 02 '19 at 10:33

Looking at the documentation I think you want to use DbModelBuilder.RegisterEntityType rather than DbModelBuilder.Entity. The documentation for the former says:

This method is provided as a convenience to allow entity types to be registered dynamically without the need to use MakeGenericMethod in order to call the normal generic Entity method.

So rather than builder.Entity<EntityType>(); you would instead use builder.RegisterEntityType(EntityType);

It is worth mentioning that often in situations like this there is a non-generic method that takes a Type object instead so if you find yourself in this situation with other software in the future check for that non-generic method with a Type parameter.

M. Galczynski · Answer 2 · 2019-04-02T11:19:00.420

1

Generic Arguments need to be resolvable during compilation. You need to use reflection to call Entity method in such loop. Please check this anwser.

Example of usage

...
MethodInfo method = typeof(DbModelBuilder).GetMethod("Entity");
MethodInfo generic = method.MakeGenericMethod(EntityType);
generic.Invoke(builder, null);

EDIT:

Also as Chris mentioned, there is no need to use reflection because DbModelBuilder provide RegisterEntityType method, which accept Type as argument, eg:

builder.RegisterEntityType(EntityType);

EDIT2: there's Chris' answer

edited Apr 02 '19 at 11:19

answered Apr 02 '19 at 10:27

M. Galczynski

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No need to use reflection - DBModelBuilder provides a method (RegisterEntityType) that takes a `Type` as a parameter and explicitly says it exists to allow you to register things without he need to use `MakeGenericMethod`. – Chris Apr 02 '19 at 10:34

score 1 · Answer 3 · answered Apr 02 '19 at 10:35

1

You use EntityType as a variable in foreach cycle, and EntityType like type in builder.Entity<EntityType>(). Change variable name from EntityType to entityType for example so C# compiler could understand your code

answered Apr 02 '19 at 10:35

NoImagination

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EntityType' is a variable but is used like a type when use the Reflection

3 Answers3