Asp.net核心2.1因模型InverseProperty而崩溃

Question

第一次调用DbContext时，我的网站在加载时崩溃，System.Reflection中有一个非常长的未处理异常。

使用ef-core 2.1 rc1

System.ArgumentNullException: Value cannot be null.
Parameter name: type
   at System.Reflection.IntrospectionExtensions.GetTypeInfo(Type type)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.InversePropertyAttributeConvention.ConfigureInverseNavigation(InternalEntityTypeBuilder entityTypeBuilder, MemberInfo navigationMemberInfo, InternalEntityTypeBuilder targetEntityTypeBuilder, InversePropertyAttribute attribute)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.InversePropertyAttributeConvention.Apply(InternalEntityTypeBuilder entityTypeBuilder, PropertyInfo navigationPropertyInfo, Type targetClrType, InversePropertyAttribute attribute)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.NavigationAttributeEntityTypeConvention`1.Apply(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ImmediateConventionScope.OnEntityTypeAdded(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.RunVisitor.VisitOnEntityTypeAdded(OnEntityTypeAddedNode node)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.OnEntityTypeAddedNode.Accept(ConventionVisitor visitor)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ConventionVisitor.Visit(ConventionNode node)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ConventionVisitor.VisitConventionScope(ConventionScope node)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ConventionBatch.Run()
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ConventionBatch.Dispose()
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.RelationshipDiscoveryConvention.DiscoverRelationships(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.RelationshipDiscoveryConvention.Apply(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ImmediateConventionScope.OnEntityTypeAdded(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.OnEntityTypeAdded(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.Model.AddEntityType(EntityType entityType)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.Model.AddEntityType(Type type, ConfigurationSource configurationSource)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.InternalModelBuilder.Entity(TypeIdentity& type, ConfigurationSource configurationSource, Boolean throwOnQuery)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.InternalModelBuilder.Entity(Type type, ConfigurationSource configurationSource, Boolean throwOnQuery)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.InversePropertyAttributeConvention.Apply(InternalEntityTypeBuilder entityTypeBuilder, PropertyInfo navigationPropertyInfo, Type targetClrType, InversePropertyAttribute attribute)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.NavigationAttributeEntityTypeConvention`1.Apply(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ImmediateConventionScope.OnEntityTypeAdded(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.OnEntityTypeAdded(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.Model.AddEntityType(EntityType entityType)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.Model.AddEntityType(Type type, ConfigurationSource configurationSource)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.InternalModelBuilder.Entity(TypeIdentity& type, ConfigurationSource configurationSource, Boolean throwOnQuery)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.InternalModelBuilder.Entity(Type type, ConfigurationSource configurationSource, Boolean throwOnQuery)
   at Microsoft.EntityFrameworkCore.ModelBuilder.Entity(Type type)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelCustomizer.FindSets(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.RelationalModelCustomizer.FindSets(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelCustomizer.Customize(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.RelationalModelCustomizer.Customize(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.CreateModel(DbContext context, IConventionSetBuilder conventionSetBuilder, IModelValidator validator)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.<>c__DisplayClass5_0.<GetModel>b__1()
   at System.Lazy`1.ViaFactory(LazyThreadSafetyMode mode)
   at System.Lazy`1.ExecutionAndPublication(LazyHelper executionAndPublication, Boolean useDefaultConstructor)
   at System.Lazy`1.CreateValue()
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.GetModel(DbContext context, IConventionSetBuilder conventionSetBuilder, IModelValidator validator)
   at Microsoft.EntityFrameworkCore.Internal.DbContextServices.CreateModel()
   at Microsoft.EntityFrameworkCore.Internal.DbContextServices.get_Model()
   at Microsoft.EntityFrameworkCore.Infrastructure.EntityFrameworkServicesBuilder.<>c.<TryAddCoreServices>b__7_1(IServiceProvider p)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, ServiceProviderEngineScope scope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProviderEngineScope scope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProviderEngineScope scope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProviderEngineScope scope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__0(ServiceProviderEngineScope scope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
   at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
   at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider()
   at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
   at Microsoft.EntityFrameworkCore.DbContext.get_Model()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityType()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityQueryable()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.System.Linq.IQueryable.get_Provider()
   at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.AsNoTracking[TEntity](IQueryable`1 source)
   at Ctrack.ReportGroups.Pages.IndexModel.OnGetAsync() in C:\Users\lukem\Documents\Visual Studio 2017\Projects\Ctrack.ReportGroups\Ctrack.ReportGroups\Pages\Index.cshtml.cs:line 34
   at Microsoft.AspNetCore.Mvc.RazorPages.Internal.ExecutorFactory.NonGenericTaskHandlerMethod.Execute(Object receiver, Object[] arguments)
   at Microsoft.AspNetCore.Mvc.RazorPages.Internal.PageActionInvoker.InvokeHandlerMethodAsync()
   at Microsoft.AspNetCore.Mvc.RazorPages.Internal.PageActionInvoker.InvokeNextPageFilterAsync()
   at Microsoft.AspNetCore.Mvc.RazorPages.Internal.PageActionInvoker.Rethrow(PageHandlerExecutedContext context)
   at Microsoft.AspNetCore.Mvc.RazorPages.Internal.PageActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.RazorPages.Internal.PageActionInvoker.InvokeInnerFilterAsync()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeNextResourceFilter()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Rethrow(ResourceExecutedContext context)
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeFilterPipelineAsync()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeAsync()
   at Microsoft.AspNetCore.Builder.RouterMiddleware.Invoke(HttpContext httpContext)
   at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.MigrationsEndPointMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.DatabaseErrorPageMiddleware.Invoke(HttpContext httpContext)
   at Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.DatabaseErrorPageMiddleware.Invoke(HttpContext httpContext)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

该问题可能与反向属性的配置有关（基于第2个语句）

组

最后2个字段是反向的

[Table("Report_Group")]
public class Group
{
    [Key, Required, Column("GroupId")]
    public int Id { get; set; }

    [Required, MaxLength(5)]
    public string OrgCode  { get; set; }

    [Required, MaxLength(100)]
    public string Name { get; set; }

    public int TierId { get; set; }

    public int? ParentGroupId { get; set; }

    public int? CostCenter { get; set; }

    [Required]
    public int ExcludeFromAlertStats { get; set; }

    [Required]
    public int GroupTypeId { get; set; }

    [ForeignKey("ParentGroupId")]
    public virtual Group Parent { get; set; }

    [ForeignKey("OrgCode")]
    public virtual Organisation Organisation { get; set; }

    [ForeignKey("TierId")]
    public virtual Tier Tier { get; set; }

    [ForeignKey("GroupTypeId")]
    public virtual GroupType GroupType { get; set; }

    [InverseProperty("GroupId")]
    public virtual IList<GroupToUnitLink> UnitLinks { get; set; }

    [InverseProperty("GroupId")]
    public virtual IList<GroupToContactLink> ContactLinks { get; set; }
}

GroupToContactLink

多对多链接表。没有InverseProperty＆＃39}。包括在内作为参考

[Table("Report_Link_Group_to_Contact")]
public class GroupToContactLink
{
    public GroupToContactLink()
    {
    }

    public GroupToContactLink(int contactId, int groupId, int linkTypeId)
    {
        this.ContactId = contactId;
        this.GroupId = groupId;
        this.LinkTypeId = linkTypeId;
    }

    [Required]
    public int ContactId { get; set; }

    [Required]
    public int GroupId { get; set; }

    [Required]
    public int LinkTypeId { get; set; }

    [ForeignKey("ContactId")]
    public virtual Contact Contact { get; set; }

    [ForeignKey("GroupId")]
    public virtual Group Group { get; set; }

    [ForeignKey("LinkTypeId")]
    public virtual ContactLinkType LinkType { get; set; }

}

GroupToUnitLink

多对多链接表。没有InverseProperty＆＃39}。包括在内作为参考

[Table("Report_Link_Group_to_Unit")]
public class GroupToUnitLink
{
    [Required]
    public int NodeId { get; set; }

    [Required]
    public int GroupId { get; set; }

    public GroupToUnitLink()
    { }

    public GroupToUnitLink(int nodeId, int groupId)
    {
        this.NodeId = nodeId;
        this.GroupId = groupId;
    }

    [ForeignKey("NodeId")]
    public virtual Unit Unit { get; set; }

    [ForeignKey("GroupId")]
    public virtual Group Group { get; set; }

}

与

还有一个InverseProperty

[Table("Report_Contact")]
public class Contact
{
    [Key, Column("ContactId")]
    public int Id { get; set; }

    [Required, StringLength(5)]
    public string OrgCode { get; set; }

    [Required, StringLength(100)]
    public string Name { get; set; }

    [StringLength(12)]
    public string Phone { get; set; }

    [StringLength(255), EmailAddress]
    public string Email { get; set; }

    [ForeignKey("OrgCode")]
    public virtual Organisation Organisation { get; set; }

    [InverseProperty("ContactId")]
    public virtual IList<GroupToContactLink> GroupLinks { get; set; }
}

这些反向属性是否配置正确？

Answer 1

您的问题是，逆属性不是GroupToContactLink类上引用Contact类的字段。

[InverseProperty("ContactId")] // Wrong: don't use the field

但是，引用联系人类的是GroupToContactLink类的导航属性。

[InverseProperty("Contact")] // Correct: use the navigation property

Answer 2

解决方法是从导航集合中删除[InverseProperty()]注释，并将以下内容添加到OnModelCreating(ModelBuilder builder)定义

    builder
        .Entity<GroupToContactLink>()
        .HasOne(gtc => gtc.Group)
        .WithMany(g => g.ContactLinks);

    builder
        .Entity<GroupToContactLink>()
        .HasOne(gtc => gtc.Contact)
        .WithMany(c => c.GroupLinks);

    builder
        .Entity<GroupToUnitLink>()
        .HasOne(gtc => gtc.Group)
        .WithMany(g => g.UnitLinks);

    builder
        .Entity<GroupToUnitLink>()
        .HasOne(gtc => gtc.Unit)
        .WithMany(c => c.GroupLinks);