// 源文件头信息：
// <copyright file="ControllersFactory.cs">
// Copyright(c)2014-2034 Kencery.All rights reserved.
// 创建人：韩迎龙(kencery)
// 创建时间：2015-6-18
// </copyright>

using System;
using System.Reflection;
using System.Web.Mvc;
using System.Web.Routing;
using System.Web.SessionState;

namespace BookSystem_Controllers
{
 /// <summary>
 /// 重写注册控制器的方法，使之能够将控制器管分离到其它类库中实现
 /// <auther>
 ///  <name>kencery</name>
 ///  <date>2015-6-18</date>
 /// </auther>
 /// </summary>
 /// 说明：IControllerFactory接口含有三个需要实现的方法：CreateController，GetControllerSessionBehavior，ReleaseController
 /// 使用：在MVC App_Start文件夹中的RouteConfig中的方法RegisterRoutes中的第一行中写入下面注册语句,Global.asax中也可注册，放到注册路由之前即可
 /// ControllerBuilder.Current.SetControllerFactory(new ControllersFactory("BookSystem_Controllers")); //BookSystem_Controllers为控制器的类库
 public class ControllersFactory : IControllerFactory
 {
  private readonly string _assemblyName;
  private readonly string _controlerDefaultNameSpage;
  private Assembly _controllerAssembly;

  /// <summary>
  /// 获取控制器所在的程序集名称
  /// </summary>
  public string AssemblyName
  {
   get { return _assemblyName; }
  }

  /// <summary>
  /// 获取控制器的默认命名空间
  /// </summary>
  public string ControlerDefaultNameSpage
  {
   get { return _controlerDefaultNameSpage; }
  }

  /// <summary>
  /// 获取控制器所在的程序集的Assembly实例
  /// </summary>
  public Assembly ControllerAssembly
  {
   get
   {
    return _controllerAssembly ?? (_controllerAssembly = Assembly.Load(AssemblyName)); //加载控制器信息
   }
  }

  /// <summary>
  /// 构造函数实例化
  /// </summary>
  /// <param name="assemblyName"></param>
  public ControllersFactory(string assemblyName)
  {
   _assemblyName = assemblyName;
  }

  /// <summary>
  /// 构造函数实例化
  /// </summary>
  /// <param name="assemblyName"></param>
  /// <param name="controlerDefaultNameSpage"></param>
  public ControllersFactory(string assemblyName, string controlerDefaultNameSpage)
  {
   _assemblyName = assemblyName;
   _controlerDefaultNameSpage = controlerDefaultNameSpage;
  }

  /// <summary>
  /// 获取控制器类的全名
  /// </summary>
  /// <param name="controllerName">控制器名称</param>
  public string GetControllerFullName(string controllerName)
  {
   return string.Format("{0}.{1}Controller",
    string.IsNullOrEmpty(ControlerDefaultNameSpage) ? AssemblyName : ControlerDefaultNameSpage,
    controllerName);
  }

  /// <summary>
  /// 获取控制器实例对象，根据controllerName生成一个没有请求上下文对象的空的控制器，在为此控制器制定ControllerContext对象，然后返回控制器实例
  /// </summary>
  /// <param name="requestContext"></param>
  /// <param name="controllerName"></param>
  public IController CreateController(RequestContext requestContext, string controllerName)
  {
   var controller = ControllerAssembly.CreateInstance(GetControllerFullName(controllerName)) as Controller;
   if (controller == null)
    return null;
   if (controller.ControllerContext == null)
   {
    controller.ControllerContext = new ControllerContext(requestContext, controller);
   }
   else
   {
    controller.ControllerContext.RequestContext = requestContext;
   }
   return controller;
  }

  /// <summary>
  /// 返回请求的会话状态的支持类型
  /// </summary>
  /// <param name="requestContext"></param>
  /// <param name="controllerName"></param>
  public SessionStateBehavior GetControllerSessionBehavior(RequestContext requestContext, string controllerName)
  {
   var controllerType = ControllerAssembly.GetType(GetControllerFullName(controllerName), true, true);
   var sessionStateAttr =
    Attribute.GetCustomAttribute(controllerType, typeof (SessionStateAttribute), false) as
     SessionStateAttribute;
   return sessionStateAttr == null ? SessionStateBehavior.Default : sessionStateAttr.Behavior;
  }

  /// <summary>
  /// 释放资源
  /// </summary>
  /// <param name="controller"></param>
  public void ReleaseController(IController controller)
  {
   var idDisposable = controller as IDisposable;
   if (idDisposable != null)
   {
    idDisposable.Dispose();
   }
  }
 }
}

//系统默认路由
  routes.MapRoute(
   name: "Default",
   url: "{controller}/{action}/{id}",
   defaults: new {controller = "Login", action = "Index", id = UrlParameter.Optional},
   namespaces: new string[] {"BookSystem_Controllers"}
);