WCF Service as a separate library - DI with Ninject

Question

This is my project diagram (in shortcut). I'm using Ninject to resolve DI in my solution.

• MyWCFService
  • App_Start
    • NinjectWebCommon.cs
  • web.config
• Friends.Implementation
  • Friends.svc
    • Friends.svc.cs
• Friends.Contract
  • IFriends.cs
• DAL.Implementation
  • Blebleble.cs
• DAL.Contract
  • IBlebleble.cs

I have a problem with my WCF Service in Friends.Implementation library.

When I have Friends.svc and Friends.svc.cs file in MyWCFService , everything is OK (DI and Ninject works).

But when I move Friends service into separate library, I get this error:

The service type provided could not be loaded as a service because it does not have a default (parameter-less) constructor. To fix the problem, add a default constructor to the type, or pass an instance of the type to the host.

Why I get that error? How to resolve it?

This is my service code:

<%@ ServiceHost Language="C#" Debug="true" Service="XYZ.Services.Friends" CodeBehind="Friends.svc.cs" Factory="Ninject.Extensions.Wcf.NinjectServiceHostFactory" %>

.CS file

    public IAccountService accountService { get; set; }
    public IFriendsService friendsService { get; set; }

    public Friends(IAccountService _acc, IFriendsService _friends)
    {
        this.accountService = _acc;
        this.friendsService = _friends;
    }

Regards.

Answer 1

对于单独库中的服务，应从ServiceHost删除CodeBehind="Friends.svc.cs"属性，并且Service属性应与服务实现的标准程序集名称匹配