当使用ServiceHost.AddServiceEndpoint添加自定义ProtoEndpointBehavior时，出现以下异常:System.ArgumentNullException:Valuecannotbenull.Parametername:keyatSystem.Collections.Generic.Dictionary2.FindEntry(TKeykey)atSystem.Collections.Generic.Dictionary2.ContainsKey(TKeykey)atSystem.ServiceModel.ServiceHostBase.Implem