graphql .NET core solution - unable to include related objects - graphql

Question

I am a newbie to graphql, and use it in a .Net core solution. My solution includes an SQlite-database, that may be accessed via a manager. I use the manager in the resolver functions in my GraphTypes. In the models, I have a class 'Ticket' and a class 'TicketResponse' - one ticket includes a list of ticketResponses.
The problem is that I am unable to include the nested data of an ObjectGraphType. Here's my code:
namespace SupportCenter.Schema.GraphQLTypes
{
public class TicketType : ObjectGraphType<Ticket>
{
public TicketType(ITicketManager manager)
{
Name = "Ticket";
Field(x => x.Id, type: typeof(IdGraphType)).Description("The id of the ticket");
Field(x => x.AccountId).Description("THe account the ticket was issued from");
Field(x => x.Text).Description("The description of the problem");
Field(x => x.DateOpened).Description("The date the ticket was opened");
Field<TicketStateEnum>("state", resolve: context => context.Source.State);
Field<ListGraphType<TicketResponseType>>("ticketresponses",
resolve: context => manager.GetTicketResponses(context.Source.Id));
}
}
}
The error I get is the following:
"GraphQL.ExecutionError: No service for type
'GraphQL.Types.ObjectGraphType1[SupportCenter.Schema.GraphQLTypes.TicketType]'
has been registered. ---> System.InvalidOperationException: No service
for type
'GraphQL.Types.ObjectGraphType1[SupportCenter.Schema.GraphQLTypes.TicketType]'
has been registered.\n at
Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider
provider, Type serviceType)\n at
GraphQL.Types.Schema.b__56_2(Type type)\n at
GraphQL.Types.GraphTypesLookup.AddTypeIfNotRegistered(Type type,
TypeCollectionContext context)\n at
GraphQL.Types.GraphTypesLookup.HandleField(Type parentType, FieldType
field, TypeCollectionContext context)\n at
GraphQL.Types.GraphTypesLookup.AddType(IGraphType type,
TypeCollectionContext context)\n at
GraphQL.Types.GraphTypesLookup.HandleField(Type parentType, FieldType
field, TypeCollectionContext context)\n at
GraphQL.Types.GraphTypesLookup.AddType(IGraphType type,
TypeCollectionContext context)\n at
GraphQL.Types.GraphTypesLookup.HandleField(Type parentType, FieldType
field, TypeCollectionContext context)\n at
GraphQL.Types.GraphTypesLookup.AddType(IGraphType type,
TypeCollectionContext context)\n at
GraphQL.Types.GraphTypesLookup.Create(IEnumerable1 types,
IEnumerable1 directives, Func2 resolveType, IFieldNameConverter
fieldNameConverter)\n at
System.Lazy1.ViaFactory(LazyThreadSafetyMode mode)\n--- End of stack
trace from previous location where exception was thrown ---\n at
System.Lazy`1.CreateValue()\n at
GraphQL.Types.Schema.get_AllTypes()\n at
GraphQL.Instrumentation.FieldMiddlewareBuilder.ApplyTo(ISchema
schema)\n at GraphQL.DocumentExecuter.ExecuteAsync(ExecutionOptions
options)\n --- End of inner exception stack trace ---",
I have registered both the TicketType and the TicketResponseType in the services in the startup-file. Any ideas what I'm doing wrong?
Here's my startup-file:
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc();
services.AddSingleton<SupportCenterDbContext>();
services.AddSingleton<TicketType>();
services.AddSingleton<TicketInputCreateType>();
services.AddSingleton<TicketResponseType>();
services.AddSingleton<TicketStateEnum>();
services.AddSingleton<ResponseQuery>();
services.AddSingleton<ITicketManager, TicketManager>();
services.AddSingleton<SupportCentreQuery>();
services.AddSingleton<TicketsQuery>();
services.AddSingleton<TicketsMutation>();
services.AddSingleton<SupportCentreSchema>();
services.AddSingleton<IDependencyResolver>(
c => new FuncDependencyResolver(c.GetRequiredService));
services.AddSingleton<IDocumentExecuter, DocumentExecuter>();
services.AddSingleton<IDocumentWriter, DocumentWriter>();
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
services.AddSingleton<IGraphQLExecuter<SupportCentreSchema>, DefaultGraphQLExecuter<SupportCentreSchema>>();
services.AddGraphQL(options =>
{
options.EnableMetrics = true;
options.ExposeExceptions = true;
})
.AddWebSockets()
.AddDataLoader();
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseDefaultFiles();
app.UseStaticFiles();
app.UseGraphQL<SupportCentreSchema>("/graphql");
app.UseGraphiQLServer(new GraphiQLOptions
{
GraphiQLPath = "/ui/graphiql",
GraphQLEndPoint = "/graphql"
});
app.UseMvc();
}
}