问在添加web api控制器的同时创建模型时，无法使用上下文

EN

public class Game
{
     [Key]
    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }
    [Required]
    public string  GameName { get; set; }
    public virtual ICollection<GameImages> GameImage { get; set; }


}
 public class GameImages
{
    [Key]
    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }
    [Required]
    [DataType(DataType.ImageUrl)]
    public string GameImageUrl { get; set; }
    public int Game_Id { get; set; }

    [ForeignKey("Game_Id")]
    public virtual Game games { get; set; }

}
 public class GameDbContext:DbContext
    {
        public GameDbContext():base("name=DefaultConnection") { }
        public DbSet<Game> Games { get; set; }
        public DbSet<GameImages> Images { get; set; }

    }

<Error>
<Message>An error has occurred.</Message>
<ExceptionMessage>
The context cannot be used while the model is being created.
</ExceptionMessage>
<ExceptionType>System.InvalidOperationException</ExceptionType>
<StackTrace>
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.ToString() at System.Data.Entity.Infrastructure.DbQuery`1.ToString() at System.Convert.ToString(Object value, IFormatProvider provider) at System.Web.Http.Tracing.FormattingUtilities.ValueToString(Object value, CultureInfo cultureInfo) at System.Web.Http.Tracing.Tracers.HttpActionDescriptorTracer.<ExecuteAsync>b__2(TraceRecord tr, Object value) at System.Web.Http.Tracing.ITraceWriterExtensions.<>c__DisplayClass1b`1.<>c__DisplayClass1f.<TraceBeginEndAsync>b__13(TraceRecord traceRecord) at System.Web.Http.Tracing.SystemDiagnosticsTraceWriter.Trace(HttpRequestMessage request, String category, TraceLevel level, Action`1 traceAction) at System.Web.Http.Tracing.ITraceWriterExtensions.<>c__DisplayClass1b`1.<TraceBeginEndAsync>b__12(TResult result) at System.Threading.Tasks.TaskHelpersExtensions.<>c__DisplayClass3b`2.<Then>b__3a(Task`1 t) at System.Threading.Tasks.TaskHelpersExtensions.ThenImpl[TTask,TOuterResult](TTask task, Func`2 continuation, CancellationToken cancellationToken, Boolean runSynchronously)
</StackTrace>
</Error>