如何在 EF DbFirst 中扩展 ASP IdentityRole

如何扩展 IdentityRoles 以使用扩展的 AspNetRoles 表？在 ASP MVC 5 中，使用 Identity 2.2 我看了here https://stackoverflow.com/q/40336574/6085193 & here https://stackoverflow.com/a/38429153/6085193答案对 DB First EF 没有帮助

Step 1:我扩展/添加了CompanyId & DescRole （使公司/租户的角色独一无二）

CREATE TABLE [dbo].[AspNetRoles]            // EXTENDED role table
    [Id] [nvarchar](50) NOT NULL,
    [Name] [nvarchar](50) NOT NULL,
    [Description] [nvarchar](50) NOT NULL,  // EXTENDED
    [CompanyId] [nvarchar](50) NOT NULL,    // EXTENDED Company/Tenant

Step 2：创建新角色是一个问题，现在我的创建角色失败，并且找不到扩展CompanyId/Desc上的属性IdentityRole (its a dbFirst EF strategy)

 //Create ROle Class
 public ActionResult CreateRole(FormCollection collection)
 {
   try {

    var context = new ApplicationDbContext();
    // RoleStore
    // var newRole = new AspNetRoles();
    // ontext.Roles.Add(new ApplicationRole) { // not visible...
    context.Roles.Add(new Microsoft.AspNet.Identity.EntityFramework.IdentityRole()
       {
            Name = collection["RoleName"],                    
       });
    context.SaveChanges();
    ViewBag.Message = "Role created successfully !";
    ...

 //Extended Role Class
 public class ApplicationRole : IdentityRole
 {
   public ApplicationRole() : base() { }
   public ApplicationRole(string name) : base(name) { }
   public string Description { get; set; }
   public string CompanyId { get; set; }
 }