我正在尝试使用 WebAPI 从 EntityFramework 检索产品名称及其 ID 作为 NameID 对象。代码如下。
public class ProductController : ApiController
{
protected MainDataContext db = new MainDataContext();
// GET /api/values
public IQueryable<NameID> Get()
{
return db.Products.Select(x=>new NameID{ ID=x.ID,Name=x.Name }).AsQueryable();
}
// GET /api/values/5
public NameID Get(long id)
{
var result = db.Products.Select(x=>new NameID{ ID=x.ID,Name=x.Name }).SingleOrDefault(x => x.ID == id);
if (id == 0 || result == null)
throw new HttpResponseException(HttpStatusCode.NotFound);
return result;
}
}
public class NameID {
public long ID {get;set;}
public string Name {get;set;}
}
它抛出如下错误
The magic number in GZip header is not correct.
Make sure you are passing in a GZip stream.
at System.IO.Compression.GZipDecoder.ReadHeader(InputBuffer input)
at System.IO.Compression.Inflater.Decode()
at System.IO.Compression.Inflater.Inflate(Byte[] bytes, Int32 offset, Int32 length)
at System.IO.Compression.DeflateStream.Read(Byte[] array, Int32 offset, Int32 count)
at System.IO.Compression.GZipStream.Read(Byte[] array, Int32 offset, Int32 count)
at System.Xml.XmlTextReaderImpl.InitStreamInput(Uri baseUri, String baseUriStr, Stream stream, Byte[] bytes, Int32 byteCount, Encoding encoding)
at System.Xml.XmlTextReaderImpl..ctor(Stream stream, Byte[] bytes, Int32 byteCount, XmlReaderSettings settings, Uri baseUri, String baseUriStr, XmlParserContext context, Boolean closeInput)
at System.Xml.XmlReaderSettings.CreateReader(Stream input, Uri baseUri, String baseUriString, XmlParserContext inputContext)
at System.Xml.XmlReader.Create(Stream input, XmlReaderSettings settings, String baseUri)
at System.Xml.Linq.XDocument.Load(Stream stream, LoadOptions options)
at System.Data.Entity.Migrations.Edm.ModelCompressor.Decompress(Byte[] bytes)
at System.Data.Entity.Migrations.History.HistoryRepository.GetLastModel(String& migrationId)
at System.Data.Entity.Migrations.History.HistoryRepository.GetLastModel()
at System.Data.Entity.Internal.InternalContext.QueryForModel()
at System.Data.Entity.Internal.ModelCompatibilityChecker.CompatibleWithModel(InternalContext internalContext, ModelHashCalculator modelHashCalculator, Boolean throwIfNoMetadata)
at System.Data.Entity.Internal.InternalContext.CompatibleWithModel(Boolean throwIfNoMetadata)
at System.Data.Entity.CreateDatabaseIfNotExists`1.InitializeDatabase(TContext context)
at System.Data.Entity.Internal.InternalContext.<>c__DisplayClass8.<PerformDatabaseInitialization>b__6()
at System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action)
at System.Data.Entity.Internal.InternalContext.PerformDatabaseInitialization()
at System.Data.Entity.Internal.LazyInternalContext.<InitializeDatabase>b__4(InternalContext c)
at System.Data.Entity.Internal.RetryAction`1.PerformAction(TInput input)
at System.Data.Entity.Internal.LazyInternalContext.InitializeDatabaseAction(Action`1 action)
at System.Data.Entity.Internal.LazyInternalContext.InitializeDatabase()
at System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType)
at System.Data.Entity.Internal.Linq.InternalSet`1.Initialize()
at System.Data.Entity.Internal.Linq.InternalSet`1.get_InternalContext()
at System.Data.Entity.Infrastructure.DbQuery`1.System.Linq.IQueryable.get_Provider()
at System.Linq.Queryable.Select[TSource,TResult](IQueryable`1 source, Expression`1 selector)
at ProductAPI.Controllers.ProductController.Get() in D:\Demo\ProductAPI\Controllers\ProductController.cs:line 24
at lambda_method(Closure , Object , Object[] )
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object instance, Object[] arguments)
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.Execute(HttpControllerContext controllerContext, IDictionary`2 arguments)
at System.Web.Http.Controllers.ApiControllerActionInvoker.<>c__DisplayClass2.<InvokeActionAsync>b__0()
at System.Threading.Tasks.TaskHelpers.RunSynchronously[TResult](Func`1 func, CancellationToken cancellationToken)