Entity Framework, Unity, and MVC - asp.net-mvc

Question

I have a multi tier application using Entity Framework, MVC and Unity.
The basic setup is like this:
EF Data Access Layer
public class MyDataProvider : DbContext, IMyDataProvider
{
public MyDataProvider(SqlConnection existingConnection, bool contextOwnsConnection)
: base(existingConnection,contextOwnsConnection)
{
((IObjectContextAdapter)this).ObjectContext.CommandTimeout = 60;
Configuration.LazyLoadingEnabled = true;
Configuration.ValidateOnSaveEnabled = true;
Configuration.ProxyCreationEnabled = true;
Configuration.AutoDetectChangesEnabled = true;
}
public new IDbSet<TModel> Set<TModel>() where TModel : class
{
return base.Set<TModel>();
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations.Add(new EmployeeMapping());
base.OnModelCreating(modelBuilder);
}
public abstract class ServiceBase<TModel> : IDisposable, IService<TModel> where TModel : class, IModel
{
[Dependency]
public IMyDataProvider MyDataProvider { get; set; }
...
}
All services inherit from this class
I then inject specific services into the Business Logic Layer like so:
public class GetEmployees
{
[Dependency("EmployeeService")]
public IEmployeeService EmployeeService { get; set;
public IQueryable<Employee> GetAllEmployees()
{
return EmployeeService.GetTable();
}
...
}
In MVC I use a controller factory
public class MyControllerFactory : DefaultControllerFactory
{
private IUnityContainer _container;
public MyControllerFactory(IUnityContainer container)
{
_container = container;
}
protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
{
if (controllerType != null)
{
return _container.Resolve(controllerType) as IController;
}
else
{
return base.GetControllerInstance(requestContext, controllerType);
}
}
Global.asax
private static IUnityContainer InitContainer()
{
IUnityContainer unityContainer = new UnityContainer();
Bootstrapper bootstrapper = new Bootstrapper(unityContainer);
return unityContainer;
}
I pass the instance of UnityContainer into the Bootstrapper class. The Bootstrapper class self registers all assemblies.
In the MVC Controllers, I inject the Business Logic like so:
public class EmployeeController
{
[Dependency("GetEmployees")]
public IBusinessLogic GetEmployees_Operations { get; set; }
public ActionResult EmployeeMain()
{
var employees = GetEmployees_Operations.GetAllEmployees();
...
}
}
This all works great up to a point. Every so often I will get an exception thrown from MyDataProvider class: "EntityConnection can only be constructed with a closed DbConnection". This seems to happen during high use of the MVC site. The exception is simple enough to understand, but how should I go about fixing it?
I found that changing how I instantiate the business logic class from a field on the controller to inside the ActionResult method, I don't recieve the exception.
For example:
public class EmployeeController
{
//[Dependency("GetEmployees")]
//public IBusinessLogic GetEmployees_Operations { get; set; }
public ActionResult EmployeeMain()
{
IBusinessLogic GetEmployees_Operations = _ioc_Bootstrapper.Resolve(typeof(IBusinessLogic), "GetEmployees") as IBusinessLogic;
var employees = GetEmployees_Operations.GetAllEmployees();
...
}
}
Have I completely missed the boat on this and implemented Unity incorrectly?
Bootstrapper code
private void RegisterDAL(String assembly)
{
var currentAssembly = Assembly.LoadFrom(assembly);
var assemblyTypes = currentAssembly.GetTypes();
foreach (var assemblyType in assemblyTypes)
{
...
if (assemblyType.FullName.EndsWith("Provider"))
{
foreach (var requiredInterface in assemblyType.GetInterfaces())
{
if (requiredInterface.FullName.EndsWith("DataProvider"))
{
var typeFrom = assemblyType.GetInterface(requiredInterface.Name);
var typeTo = assemblyType;
var injector = GetInjectorConstructor(assemblyType.Module.Name);
RegisterType(typeFrom, typeTo, false, injector);
}
}
continue;
}
...
}
private InjectionConstructor GetInjectorConstructor(String moduleName)
{
...
connString = String.Concat("Data Source=MySqlServer, ";Initial Catalog=", catalogName, ";Application Name=", applicationName, ";Integrated Security=True; );
var conn = new SqlConnection(connString);
return new InjectionConstructor(conn, true);
}