Cascade Deactivate Related Records Using Plugin in CRM

Today came up with a task regarding how we can deactivate related child records once parent record is getting deactivated.Below Screenshot shared :
 
Here My Requirement is : In Account entity i have lookup field with Event Entity(Parent Record).
Once Event record gets deactivated then related child records(Account Record) associated with Event entity must be deactivated.
I have done using c# plugin code.

1. Please find the below code :

public void Execute(IServiceProvider serviceProvider)
       {
           ITracingService tracingService = (ITracingService)serviceProvider.GetService(typeof(ITracingService));
           IPluginExecutionContext context = (IPluginExecutionContext)serviceProvider.GetService(typeof(IPluginExecutionContext));
           IOrganizationServiceFactory factory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));
           IOrganizationService service = factory.CreateOrganizationService(context.UserId);

           if (context.InputParameters.Contains("EntityMoniker") && context.InputParameters["EntityMoniker"] is EntityReference)
           {
               var entity = (EntityReference)context.InputParameters["EntityMoniker"];
               var state = (OptionSetValue)context.InputParameters["State"];
               var status = (OptionSetValue)context.InputParameters["Status"];

               if(entity.LogicalName=="ags_event" && state.Value==1)
               {
                   QueryExpression account = new QueryExpression { EntityName = "account", ColumnSet = new ColumnSet("accountid", "ags_event") };
                   account.Criteria.AddCondition("ags_event", ConditionOperator.Equal, entity.Id);
                   account.Criteria.AddCondition("statecode", ConditionOperator.Equal, 0);
                   EntityCollection retrieveAccount = service.RetrieveMultiple(account);

                   if (retrieveAccount.Entities.Count > 0)
                   {
                       foreach (var a in retrieveAccount.Entities)
                       {
                           SetStateRequest accountRequest = new SetStateRequest();
                           accountRequest.EntityMoniker = new EntityReference(a.LogicalName, new Guid(a.Id.ToString()));
                           accountRequest.State = new OptionSetValue(1);
                           accountRequest.Status = new OptionSetValue(-1);
                           service.Execute(accountRequest);
                       }
                   }

               }
               if (state.Value == 0)
               {
                   QueryExpression account = new QueryExpression { EntityName = "account", ColumnSet = new ColumnSet("accountid", "ags_event") };

                   account.Criteria.AddCondition("ags_event", ConditionOperator.Equal, entity.Id);
                   account.Criteria.AddCondition("statecode", ConditionOperator.Equal, 1);
                   EntityCollection retrieveAccount = service.RetrieveMultiple(account);


                   if (retrieveAccount.Entities.Count > 0)
                   {
                       foreach (var a in retrieveAccount.Entities)
                       {
                           SetStateRequest accountRequest = new SetStateRequest();
                           accountRequest.EntityMoniker = new EntityReference(a.LogicalName, new Guid(a.Id.ToString()));
                           accountRequest.State = new OptionSetValue(0);
                           accountRequest.Status = new OptionSetValue(-1);
                           service.Execute(accountRequest);
                       }
                   }
               }
           }
       }
2. Register this c# code on setStateDynamicEntity Message using Plugin Registration Tool.



Hope it would be helpful to someone !!