我只是尝试了实体框架5和kendo ui的一些功能。我有以下 ProductType 枚举
public enum ProductType {
[Description("Hazardous")]
Hazardous,
[Description("Non Hazardous")]
NonHazardous
}
此枚举类型是产品实体中的字段之一。
[Table("Products")]
public class Product {
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
//Other Fields ...
[Required(ErrorMessage="Product Type is Required")]
public ProductType ProductType {get;set;}
}
基础SQL Server数据库中的ProductType列定义为(tinyint,not null)。
我在MVC的以下控制器操作中访问产品列表
public ActionResult _ProductList(int pageSize, int skip) {
using (WorkUnit workUnit = new WorkUnit()) {
IQueryable<Product> products = workUnit.ProductRepository.GetAllProducts()
.Include(p => p.Category);
int total = products.Count();
List<Product> productList = products.ToList<Product>(); //Throws InvalidOperationException
return Json(new { total = total, data = productList }, JsonRequestBehavior.AllowGet);
}
}
以上是上述控制器操作中 products.ToList()引发的InvalidOperationException的描述。
The 'ProductType' property on 'Product' could not be set to a 'Byte' value.
You must set this property to a non-null value of type 'ProductType'.
任何猜测 ToList()为什么会抛出 InvalidOperationException 。
仅供参考,数据库以前存在,实体是根据数据库手动编码为POCO的。
修改
以下是完整的异常详情
System.InvalidOperationException was unhandled by user code
HResult=-2146233079
Message=The 'ProductType' property on 'Product' could not be set to a 'Byte' value. You must set this property to a non-null value of type 'ProductType'.
Source=System.Data.Entity
StackTrace:
at System.Data.Common.Internal.Materialization.Shaper.ErrorHandlingValueReader`1.GetValue(DbDataReader reader, Int32 ordinal)
at System.Data.Common.Internal.Materialization.Shaper.GetPropertyValueWithErrorHandling[TProperty](Int32 ordinal, String propertyName, String typeName)
at lambda_method(Closure , Shaper )
at System.Data.Common.Internal.Materialization.Shaper.HandleEntityAppendOnly[TEntity](Func`2 constructEntityDelegate, EntityKey entityKey, EntitySet entitySet)
at lambda_method(Closure , Shaper )
at System.Data.Common.Internal.Materialization.Coordinator`1.ReadNextElement(Shaper shaper)
at System.Data.Common.Internal.Materialization.Shaper`1.SimpleEnumerator.MoveNext()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at KendoUI_Web_Demo.Controllers.HomeController._ProductList(Int32 pageSize, Int32 skip) in d:\Practice\ASP.NET_MVC\KendoUI_Web_Demo\KendoUI_Web_Demo\Controllers\HomeController.cs:line 52
at lambda_method(Closure , ControllerBase , Object[] )
at System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters)
at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41()
at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass37.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49()
InnerException:
答案 0 :(得分:16)
在您的情况下基于int
的枚举类型与基于字节(tinyint)的列的数据库之间存在不匹配。您可以通过设置枚举类型的正确基础类型来解决此问题:
public enum ProductType : byte
{
...
}