entity-framework - Breeze.js 不支持具有 TimeSpan 属性的 EF 实体？

Question

在向 DocCode 项目中的 Employee 实体添加 TimeSpan 属性后，我收到 NotSupportedException 。所以我知道它不受支持，但是......是否有计划进行转换或解决此问题的方法。我们在实体中广泛使用 TimeSpan，有没有办法支持 TimeSpan 或计划支持？

添加持续时间属性

public class Employee
{
    ...
    public DateTime? HireDate { get; set; }

    public TimeSpan? Duration { get; set; }

    [MaxLength(60)]
    public string Address { get; set; }
    ...
}

当在运行单元测试的 NorthwindController 上调用 MetaData() 方法时，它会失败:

System.NotSupportedException was unhandled by user code
HResult=-2146233067
Message=There is no store type corresponding to the EDM type 'Edm.Time(Nullable=True)' of primitive type 'Time'.
Source=System.Data.SqlServerCe.Entity
StackTrace:
   at System.Data.SqlServerCe.SqlCeProviderManifest.GetStoreType(TypeUsage edmType)
   at System.Data.Entity.ModelConfiguration.Edm.Services.StructuralTypeMappingGenerator.MapTableColumn(EdmProperty property, DbTableColumnMetadata tableColumnMetadata, Boolean isInstancePropertyOnDerivedType, Boolean isKeyProperty)
   at System.Data.Entity.ModelConfiguration.Edm.Services.PropertyMappingGenerator.Generate(EdmEntityType entityType, IEnumerable`1 properties, DbEntitySetMapping entitySetMapping, DbEntityTypeMappingFragment entityTypeMappingFragment, IList`1 propertyPath, Boolean createNewColumn)
   at System.Data.Entity.ModelConfiguration.Edm.Services.EntityTypeMappingGenerator.Generate(EdmEntityType entityType, DbDatabaseMapping databaseMapping)
   at System.Data.Entity.ModelConfiguration.Edm.Services.DatabaseMappingGenerator.GenerateEntityTypes(EdmModel model, DbDatabaseMapping databaseMapping)
   at System.Data.Entity.ModelConfiguration.Edm.Services.DatabaseMappingGenerator.Generate(EdmModel model)
   at System.Data.Entity.ModelConfiguration.Edm.EdmModelExtensions.GenerateDatabaseMapping(EdmModel model, DbProviderManifest providerManifest)
   at System.Data.Entity.DbModelBuilder.Build(DbProviderManifest providerManifest, DbProviderInfo providerInfo)
   at System.Data.Entity.DbModelBuilder.Build(DbConnection providerConnection)
   at System.Data.Entity.Internal.LazyInternalContext.CreateModel(LazyInternalContext internalContext)
   at System.Data.Entity.Internal.RetryLazy`2.GetValue(TInput input)
   at System.Data.Entity.Internal.LazyInternalContext.InitializeContext()
   at System.Data.Entity.Internal.InternalContext.Initialize()
   at System.Data.Entity.Internal.InternalContext.ForceOSpaceLoadingForKnownEntityTypes()
   at System.Data.Entity.DbContext.System.Data.Entity.Infrastructure.IObjectContextAdapter.get_ObjectContext()
   at Breeze.WebApi.EFContextProvider`1.GetCsdlFromObjectContext(Object context)
   at Breeze.WebApi.EFContextProvider`1.GetCsdlFromDbContext(Object context)
   at Breeze.WebApi.EFContextProvider`1.BuildJsonMetadata()
   at Breeze.WebApi.ContextProvider.Metadata()
   at DocCode.Controllers.NorthwindController.Metadata() in c:\Users\anwalker\Downloads\breeze-runtime-plus-0.78.2\Samples\DocCode\DocCode\Controllers\NorthwindController.cs:line 20
   at lambda_method(Closure , Object , Object[] )
   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass13.<GetExecutor>b__c(Object instance, Object[] methodParameters)
   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object instance, Object[] arguments)
   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.<>c__DisplayClass5.<ExecuteAsync>b__4()
   at System.Threading.Tasks.TaskHelpers.RunSynchronously[TResult](Func`1 func, CancellationToken cancellationToken)
InnerException: 

Answer 1

好的，经过一些研究，使用 ISO8601 'duration' 标准将 .NET 时间跨度序列化到 javascript 客户端是有意义的，该标准将时间跨度以天、小时、分钟和秒表示为格式字符串，例如:“PnnnDTnnHnnMnn .nnnS”。显然，您将需要客户端上的 javascript 库来解释和使用它。这会满足您的需求吗？

我已将此添加到我们的功能请求日志中，但也请将其添加到 Breeze User Voice (并投票给它:))。这有助于我们优先处理未完成的功能请求。