Asp.net mvc 使用ASP.NET标识的WinForms应用程序中的ModelValidationException:EntityType未定义键

我正在使用ASP.NET MVC5和ASP.NET身份验证来开发一个web应用程序。我的数据库首先是用EF代码建立的。我使用以下属性扩展了ApplicationUser：

public class ApplicationUser : IdentityUser
{
    [StringLength(80)]
    [Display(Name = "FullName", ResourceType = typeof(Resources.Resources))]
    public string FullName { get; set; }

    // More properties

    public virtual ICollection<Installation> Installations { get; set; }

    public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser> manager)
    {
        // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
        var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
        // Add custom user claims here
        return userIdentity;
    }
}

公共类应用程序用户：IdentityUser
{
[条次建议修正案（80）]
[显示（Name=“FullName”，ResourceType=typeof（Resources.Resources））]
公共字符串全名{get；set；}
//更多属性
公共虚拟ICollection安装{get；set；}
公共异步任务GenerateUserIdentityAsync（UserManager我使用以下两行代码使用用户和密码登录：

var userManager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext()));
ApplicationUser user = await userManager.FindAsync(this.tbUser.Text, this.tbPassword.Text);

var userManager=new userManager以获取更多信息，但这些是不同的异常，因此它永远不会进入catch块

最奇怪的是，在它工作正常之前，我不知道我做了什么，现在我得到了这个错误。
我已经解决了重写ApplicationDbContext类的ModelCreating方法并指定键的问题：

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
     modelBuilder.Entity<Installation>().HasKey(c => c.Imei);
     base.OnModelCreating(modelBuilder);
}

模型创建时受保护的覆盖无效（DbModelBuilder modelBuilder）
{
modelBuilder.Entity（）.HasKey（c=>c.Imei）；
基于模型创建（modelBuilder）；
}

System.Data.Entity.ModelConfiguration.ModelValidationException was unhandled by user code
  HResult=-2146233088
  Message=One or more validation errors were detected during model generation:

MyProjectWeb.Models.Installation: : EntityType 'Installation' has no key defined. Define the key for this EntityType.
Installations: EntityType: EntitySet 'Installations' is based on type 'Installation' that has no keys defined.

  Source=EntityFramework
  StackTrace:
       at System.Data.Entity.Core.Metadata.Edm.EdmModel.Validate()
       at System.Data.Entity.DbModelBuilder.Build(DbProviderManifest providerManifest, DbProviderInfo providerInfo)
       at System.Data.Entity.DbModelBuilder.Build(DbConnection providerConnection)
       at System.Data.Entity.Internal.LazyInternalContext.CreateModel(LazyInternalContext internalContext)
       at System.Data.Entity.Internal.RetryLazy`2.GetValue(TInput input)
       at System.Data.Entity.Internal.LazyInternalContext.InitializeContext()
       at System.Data.Entity.Internal.InternalContext.Initialize()
       at System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType)
       at System.Data.Entity.Internal.Linq.InternalSet`1.Initialize()
       at System.Data.Entity.Internal.Linq.InternalSet`1.Include(String path)
       at System.Data.Entity.Infrastructure.DbQuery`1.Include(String path)
       at System.Data.Entity.QueryableExtensions.Include[T](IQueryable`1 source, String path)
       at System.Data.Entity.QueryableExtensions.Include[T,TProperty](IQueryable`1 source, Expression`1 path)
       at Microsoft.AspNet.Identity.EntityFramework.UserStore`6.GetUserAggregateAsync(Expression`1 filter)
       at Microsoft.AspNet.Identity.EntityFramework.UserStore`6.FindByNameAsync(String userName)
       at Microsoft.AspNet.Identity.UserManager`2.FindByNameAsync(String userName)
       at Microsoft.AspNet.Identity.UserManager`2.<FindAsync>d__12.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
       at MyProjectForm.FormConectar.<Login>d__2.MoveNext() in f:\...\Solution\MyProjectForm\FormConectar.cs:line 158
  InnerException: 

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
     modelBuilder.Entity<Installation>().HasKey(c => c.Imei);
     base.OnModelCreating(modelBuilder);
}