嘗試$ expand可導航屬性時出錯

Question

我正在使用最新的ASP.NET每晚構建。在我的REST API（EntitySetController爲主），當我嘗試$展開導航屬性是空在數據庫中，我得到以下錯誤：

"message": "The EDM instance of type '[Communicator.Model.ContentTemplateGroup Nullable=True]' is missing the property 'GUID'.", 
"type": "System.InvalidOperationException", 
"stacktrace": " at System.Web.Http.OData.EntityInstanceContext.GetPropertyValue(String propertyName) 

REST調用林macking是：

/ContentTemplate?$expand=ContentTemplateGroup 

只有在數據庫中存在'ContentTemplateGroup'的ContentTemplate實例（空FK）時纔會發生這種情況。對於具有ContentTemplateGroup的ContentTemplates，$ expand可以正常工作。我的實體看起來像如下：

public class ContentTemplate: IIdentifier 
{ 
    public int? Id { get; set; } 

    [Required] 
    public Guid GUID { get; set; } 

    public virtual ContentTemplateGroup ContentTemplateGroup { get; set; } 
    public virtual ICollection<ContentTemplateField> ContentTemplateFields { get; set; } 
} 

public class ContentTemplateGroup : IIdentifier 
{ 
    public int? Id { get; set; } 

    [Required] 
    public Guid GUID { get; set; } 

    [Required] 
    public string Name { get; set; } 

    public virtual IList<ContentTemplate> ContentTemplate { get; set; } 
} 

，當我嘗試使用集合擴大導航屬性我沒有得到這個錯誤。以下的工作就像一個魅力：

http://localhost:64316/rest/ContentTemplate?$expand=ContentTemplateFields 

更新：（？INT）使得實體主鍵爲空的之前，我得到一個不同的錯誤進行了同樣的問題情境。錯誤是：

"message": "The cast to value type 'System.Int32' failed because the materialized value is null. Either the result type's generic parameter or the query must use a nullable type.", 
"type": "System.InvalidOperationException", 
"stacktrace": " at System.Data.Entity.Core.Common.Internal.Materialization.Shaper.ErrorHandlingValueReader`1.GetValue(DbDataReader reader, Int32 ordinal)\r\n at System.Data.Entity.Core.Common.Internal.Materialization.Shaper.GetColumnValueWithErrorHandling[TColumn](Int32 ordinal)\r\n at lambda_method(Closure , Shaper)\r\n at System.Data.Entity.Core.Common.Internal.Materialization.Coordinator`1.ReadNextElement(Shaper shaper)\r\n at System.Data.Entity.Core.Common.Internal.Materialization.Shaper`1.SimpleEnumerator.MoveNext()\r\n at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext()\r\n at System.Web.Http.OData.Formatter.Serialization.ODataFeedSerializer.WriteFeed(IEnumerable enumerable, ODataWriter writer, ODataSerializerContext writeContext) 

Answer 1

這是一個已知問題（1043: $expand fails when the navigation property being expanded is null）。我剛剛檢查了fix。你能否在明天晚上抓住我們最近的夜間建築並確認問題是否已經消失？