构建ASP.NET MVC3 控制器

MvcRouteHandler是默认的标准路由处理器类，它将创建一个MvcHandler实例对象，而MvcHandler又是默认的MVC Handler处理类

它只有一个构造器，且要传递RequestContext类型作为参数，因此它是不能注册到站点的处理程序列表中的。

MVC模式下，实现IControllerFactory接口的类来获取当前的请求控制器对象

而 MvcHandler 通过ControllerBuilder类来获取实现IControllerFactory接口的控制器工厂

详细如下

　　MvcHandler的ProcessRequestInit方法代码：

  private ControllerBuilder _controllerBuilder; private void ProcessRequestInit(HttpContextBase httpContext, out IController controller, out IControllerFactory factory)
{
    if (ValidationUtility.IsValidationEnabled(HttpContext.Current) == true)
    {
        ValidationUtility.EnableDynamicValidation(HttpContext.Current);
    }
    this.AddVersionHeader(httpContext);
    this.RemoveOptionalRoutingParameters();
    string requiredString = this.RequestContext.get_RouteData().GetRequiredString("controller");
    factory = this.ControllerBuilder.GetControllerFactory();
    controller = factory.CreateController(this.RequestContext, requiredString);
    if (controller == null)
    {
        throw new InvalidOperationException(string.Format(CultureInfo.CurrentCulture, MvcResources.ControllerBuilder_FactoryReturnedNull, new object[] { factory.GetType(), requiredString }));
    }
}

 IControllerFactory接口：

public interface IControllerFactory
{
    // Methods
    IController CreateController(RequestContext requestContext, string controllerName);
    SessionStateBehavior GetControllerSessionBehavior(RequestContext requestContext, string controllerName);
    void ReleaseController(IController controller);
}

 DefaultControllerFactory:

public class DefaultControllerFactory : IControllerFactory
{
    // Fields
    private IResolver<IControllerActivator> _activatorResolver;
    private IBuildManager _buildManager;
    private IControllerActivator _controllerActivator;
    private ControllerBuilder _controllerBuilder;
    private ControllerTypeCache _instanceControllerTypeCache;
    private static readonly ConcurrentDictionary<Type, SessionStateBehavior> _sessionStateCache;
    private static ControllerTypeCache _staticControllerTypeCache;

    // Methods
    static DefaultControllerFactory();
    public DefaultControllerFactory();
    public DefaultControllerFactory(IControllerActivator controllerActivator);
    internal DefaultControllerFactory(IControllerActivator controllerActivator, IResolver<IControllerActivator> activatorResolver, IDependencyResolver dependencyResolver);
    internal static InvalidOperationException CreateAmbiguousControllerException(RouteBase route, string controllerName, ICollection<Type> matchingTypes);
    public virtual IController CreateController(RequestContext requestContext, string controllerName);
    protected internal virtual IController GetControllerInstance(RequestContext requestContext, Type controllerType);
    protected internal virtual SessionStateBehavior GetControllerSessionBehavior(RequestContext requestContext, Type controllerType);
    protected internal virtual Type GetControllerType(RequestContext requestContext, string controllerName);
    private Type GetControllerTypeWithinNamespaces(RouteBase route, string controllerName, HashSet<string> namespaces);
    public virtual void ReleaseController(IController controller);
    SessionStateBehavior IControllerFactory.GetControllerSessionBehavior(RequestContext requestContext, string controllerName);

    // Properties
    internal IBuildManager BuildManager { get; set; }
    private IControllerActivator ControllerActivator { get; }
    internal ControllerBuilder ControllerBuilder { get; set; }
    internal ControllerTypeCache ControllerTypeCache { get; set; }

    // Nested Types
    private class DefaultControllerActivator : IControllerActivator
    {
        // Fields
        private Func<IDependencyResolver> _resolverThunk;

        // Methods
        public DefaultControllerActivator();
        public DefaultControllerActivator(IDependencyResolver resolver);
        public IController Create(RequestContext requestContext, Type controllerType);
    }
}

 

 ControllerBuilder:

public class ControllerBuilder
{
    // Fields
    private Func<IControllerFactory> _factoryThunk;
    private static ControllerBuilder _instance;
    private HashSet<string> _namespaces;
    private IResolver<IControllerFactory> _serviceResolver;
    // Methods
    static ControllerBuilder();
    public ControllerBuilder();
    internal ControllerBuilder(IResolver<IControllerFactory> serviceResolver);
    public IControllerFactory GetControllerFactory();
    public void SetControllerFactory(Type controllerFactoryType);
    public void SetControllerFactory(IControllerFactory controllerFactory);
    // Properties
    public static ControllerBuilder Current { get; }
    public HashSet<string> DefaultNamespaces { get; }
}

具体流程如下：

MvcHander-->ControllerBuilder-->IControllerFactory-->Controller