Bestpractice DI与ASP.NET MVC和StructureMap - 如何在一个ActionResult注入依赖 [英] Bestpractice DI with ASP.NET MVC and StructureMap - How to inject dependencies in an ActionResult

问题描述

我编辑我的整个问题，所以不要奇怪：）

I edited my whole question, so do not wonder :)

好吧，我想有一个的ActionResult 这需要域模型数据和一些额外的参数，即页面索引和页面大小分页列表。它决定自己是否会返回一个PartialViewResult或根据其种类Web请求（Ajax请求与否）的的ViewResult。

Well, I want to have an ActionResult that takes domain model data and some additional parameters, i.e page index and page size for paging a list. It decide itself if it returns a PartialViewResult or a ViewResult depending on the kind of web request (ajax request or not).

的下文称数据应通过使用IMappingService，它负责将任何域模型数据转换成一个视图模型自动映射。
该MappingService使用AutoMapper为简单起见。

The reffered data shall be mapped automatically by using an IMappingService, which is responsible for transforming any domain model data into a view model. The MappingService uses AutoMapper for simplicity.

MappingActionResult：

MappingActionResult:

public abstract class MappingActionResult : ActionResult
{
    public static IMappingService MappingService;
}

BaseHybridViewResult：

BaseHybridViewResult:

public abstract class BaseHybridViewResult : MappingActionResult
{
    public const string defaultViewName = "Grid";

    public string ViewNameForAjaxRequest { get; set; }
    public object ViewModel { get; set; }

    public override void ExecuteResult(ControllerContext context)
    {
        if (context == null) throw new ArgumentNullException("context");
        var usePartial = ShouldUsePartial(context);
        ActionResult res = GetInnerViewResult(usePartial);

        res.ExecuteResult(context);
    }

    private ActionResult GetInnerViewResult(bool usePartial)
    {
        ViewDataDictionary viewDataDictionary = new ViewDataDictionary(ViewModel);
        if (String.IsNullOrEmpty(ViewNameForAjaxRequest))
        {
            ViewNameForAjaxRequest = defaultViewName;
        }

        if (usePartial)
        {
            return new PartialViewResult { ViewData = viewDataDictionary, ViewName = ViewNameForAjaxRequest };
        }

        return new ViewResult { ViewData = viewDataDictionary };
    }

    private static bool ShouldUsePartial(ControllerContext context)
    {
        return context.HttpContext.Request.IsAjaxRequest();
    }
}

AutoMappedHybridViewResult：

AutoMappedHybridViewResult:

public class AutoMappedHybridViewResult<TSourceElement, TDestinationElement> : BaseHybridViewResult
{
    public AutoMappedHybridViewResult(PagedList<TSourceElement> pagedList)
    {
        ViewModel = MappingService.MapToViewModelPagedList<TSourceElement, TDestinationElement>(pagedList);
    }

    public AutoMappedHybridViewResult(PagedList<TSourceElement> pagedList, string viewNameForAjaxRequest)
    {
        ViewNameForAjaxRequest = viewNameForAjaxRequest;
        ViewModel = MappingService.MapToViewModelPagedList<TSourceElement, TDestinationElement>(pagedList);
    }

    public AutoMappedHybridViewResult(TSourceElement model)
    {
        ViewModel = MappingService.Map<TSourceElement, TDestinationElement>(model);
    }

    public AutoMappedHybridViewResult(TSourceElement model, string viewNameForAjaxRequest)
    {
        ViewNameForAjaxRequest = viewNameForAjaxRequest;
        ViewModel = MappingService.Map<TSourceElement, TDestinationElement>(model);
    }
}

在控制器用法：

public ActionResult Index(int page = 1)
{
    return new AutoMappedHybridViewResult<TeamEmployee, TeamEmployeeForm>(_teamEmployeeRepository.GetPagedEmployees(page, PageSize));
}

因此​​，大家可以看到 IMappingService 是隐藏的。控制器不应该知道关于 IMappingService 接口，当 AutoMappedHybridViewResult 用于任何东西。

So as you can see the IMappingService is hidden. The controller should not know anything about the IMappingService interface, when AutoMappedHybridViewResult is used.

是 MappingActionResult 与静态IMappingServer 适当的还是我违反原则DI

Is the MappingActionResult with the static IMappingServer appropriate or am I violating the DI principle?

推荐答案

我觉得更好的设计是有依赖于IMappingService一个ViewResultFactory，那么你可以注入该到控制器。然后调用它像这样：

I think a better design is to have a ViewResultFactory that depends on IMappingService, then you can inject that into your controller. Then you call it like so:

public class MyController : Controller
{
    IViewResultFactory _viewResultFactory;
    ITeamEmployeeRepository _teamEmployeeRepository;

    public MyController(IViewResultFactory viewResultFactory)
    {
        _viewResultFactory = viewResultFactory;
    }

    public ActionResult MyAction(int page, int pageSize)
    {
        return
            _viewResultFactory.GetResult<TeamEmployee, TeamEmployeeForm>(
                _teamEmployeeRepository.GetPagedEmployees(page, pageSize));
    }
}

的实施将是这样的（你需要为每个HybridViewResult构造函数重载创建）：

The implementation would like this (you would need to create overloads for each of your HybridViewResult constructors):

public HybridViewResult<TSourceElement, TDestinationElement> GetResult<TSourceElement, TDestinationElement>(PagedList<TSourceElement> pagedList)
{
    return new HybridViewResult<TSourceElement, TDestinationElement>(_mappingService, pagedList);
}

这样，你隐藏你的控制器的实现，你不必依赖于容器。

That way you hide the implementation from your controllers, and you don't have to depend on the container.

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