Question

所以我正在构建一个可以使用插件扩展的MVC Web应用程序。插件可以放入一个文件夹中，如果应用程序重新启动，它们就会被加载。我遇到的问题是插件中的一些/大多数控制器都有带参数的构造函数。我已经有一个自定义控制器工厂，可以在运行时创建必要的控制器，但问题在于控制器的注册。我目前有：

CustomControllerFactory factory = new CustomControllerFactory();
factory.RegisterFactoryMethod<MyController>(() => new MyController(_myDependecy));

以controllerfactory为：

public class CustomControllerFactory : DefaultControllerFactory
{

    private Dictionary<string, Func<IController>> _factoryMethods = new Dictionary<string, Func<IController>>();

    public void RegisterFactoryMethod<T>(Func<IController> factoryMethod)
                where T : IController
    {
        string controllerName = ConvertToControllerName<T>();

        if (_factoryMethods.ContainsKey(controllerName))
            throw new Exception(String.Format("FactoryMethod for controller '{0}'is already registered.", controllerName));

        _factoryMethods[controllerName] = factoryMethod;
    }


    private string ConvertToControllerName<T>()
    {
        string fullName = typeof (T).Name;
        //Cut of "Controller"
        return fullName.Substring(0, fullName.Length - 10);
    }

    public override IController CreateController(System.Web.Routing.RequestContext requestContext, string controllerName)
    {

        if (_factoryMethods.ContainsKey(controllerName))
            return _factoryMethods[controllerName]();

        return base.CreateController(requestContext, controllerName);

    }
}

但是这需要我知道在编译时要添加哪些控制器与哪个依赖项。如何在运行时从程序集中获取控制器及其依赖项？

Answer 1

我最终找到了一个解决方案，但它并不是完全通用的，因为我只考虑具有已知依赖性的构造函数。

Type[] controllers = assembly.GetTypes().Where(x => x.BaseType == typeof(Controller)).ToArray();
foreach (Type controller in controllers)
    {
        ConstructorInfo[] constructors = controller.GetConstructors();

        foreach (var constructor in constructors)
        {
            RegisterControllerConstructor(constructor,_MyDependecy,controller,factory);
        }
    }
}

private void RegisterControllerConstructor(ConstructorInfo constructor, MyDependecy _MyDependecy, Type controller, CustomControllerFactory factory)
    {
        ParameterInfo[] parameters = constructor.GetParameters();
        Type[] paraTypes = parameters.Select(p => p.ParameterType).ToArray();
        MethodInfo method =
            factory.GetType().GetMethod("RegisterFactoryMethod").MakeGenericMethod(controller);
        if (paraTypes.Length == 1 && paraTypes[0] == _MyDependecy.GetType())
        {
            var param = new object[1];

            Func<IController> action = () =>
            {
                return Activator.CreateInstance(controller, _MyDependecy) as IController;
            };

            param[0] = action;

            method.Invoke(factory, param);

        }
    }

MVC：如何在运行时获取控制器及其依赖项

1 个答案: