Question

我一直试图找到一种方法让模型绑定继续使用带有参数的构造函数的模型。

行动：

 [HttpPost]
        public ActionResult Create(Company company, HttpPostedFileBase logo)
        {
            company.LogoFileName = SaveCompanyLogoImage(logo);
            var newCompany = _companyProvider.Create(company);
            return View("Index",newCompany);
        }

和模型

public  Company(CustomProfile customProfile)
        {
            DateCreated = DateTime.Now;
            CustomProfile = customProfile;
        }

我完成了我的研究，似乎我需要弄乱我的ninjectControllerfactory：

  public class NinjectControllerFactory : DefaultControllerFactory
    {
        private readonly IKernel ninjectKernel;

        public NinjectControllerFactory()
        {
            ninjectKernel = new StandardKernel();
            AddBindings();
        }

        protected override IController GetControllerInstance(RequestContext requestContext,
                                                             Type controllerType)
        {
            return controllerType == null
                       ? null
                       : (IController) ninjectKernel.Get(controllerType);
        }

        private void AddBindings()
        {
            ninjectKernel.Bind<IAuthProvider>().To<FormsAuthProvider>();
            ninjectKernel.Bind<IMembershipProvider>().To<MembershipProvider>();
            ninjectKernel.Bind<ICustomProfileProvider>().To<CustomProfileProvider>();
            ninjectKernel.Bind<ICompanyProvider>().To<CompanyProvider>();
        }
    }

我也觉得我需要修改我的模型绑定器，但我不清楚前进的方向：

 public class CustomProfileModelBinder : IModelBinder
{
    private const string sessionKey = "CustomProfile";

    #region IModelBinder Members

    public object BindModel(ControllerContext controllerContext,
                            ModelBindingContext bindingContext)
    {
        // get the Cart from the session 
        var customProfile = (CustomProfile) controllerContext.HttpContext.Session[sessionKey];
        // create the Cart if there wasn't one in the session data
        if (customProfile == null)
        {
            customProfile = new CustomProfile("default name");
            controllerContext.HttpContext.Session[sessionKey] = customProfile;
        }
        // return the cart
        return customProfile;
    }

    #endregion
}

希望这能解释我的问题，如果这是一个相当冗长的问题，我很抱歉！

感谢您的帮助

Answer 1

在这种情况下，似乎必须从会话中获取您需要创建的参数（CustomProfile）。然后，您可以使用特定的模型绑定器来从默认模型绑定器派生的Company模型，仅更改它创建Company类实例的方式（然后它将以与默认类型相同的方式填充属性）： / p>

public class CompanyModelBinder: DefaultModelBinder
{
    private const string sessionKey = "CustomProfile";

    protected override object CreateModel(ControllerContext controllerContext,
                                         ModelBindingContext bindingContext,
                                         Type modelType)
    {
        if(modelType == typeOf(Company))
        {
            var customProfile = (CustomProfile) controllerContext.HttpContext.Session[sessionKey];
            // create the Cart if there wasn't one in the session data
            if (customProfile == null)
            {
                customProfile = new CustomProfile("default name");
                controllerContext.HttpContext.Session[sessionKey] = customProfile;
            }

            return new Company(customProfile);
        }
        else
        {
            //just in case this gets registered for any other type
            return base.CreateModel(controllerContext, bindingContext, modelType)
        }
    }
}

通过将此绑定添加到global.asax Application_Start方法，您将仅为公司类型注册此绑定程序：

ModelBinders.Binders.Add(typeOf(Company), CompanyModelBinder);

另一种选择可能是通过继承DefaultModelBinder来使用Ninject依赖项创建依赖项感知模型绑定器（因为您使用的是Ninject，它知道如何构建具体类型的实例而无需注册它们）。但是，您需要配置一个在Ninject中构建CustomProfile的自定义方法，我相信您可以使用ToMethod（）。为此，您将提取您将在控制器工厂外提取Ninject内核的配置：

public static class NinjectBootStrapper{
    public static IKernel GetKernel()
    {
        IKernel  ninjectKernel = new StandardKernel();
        AddBindings(ninjectKernel);
    }

    private void AddBindings(IKernel ninjectKernel)
    {
        ninjectKernel.Bind<IAuthProvider>().To<FormsAuthProvider>();
        ninjectKernel.Bind<IMembershipProvider>().To<MembershipProvider>();
        ninjectKernel.Bind<ICustomProfileProvider>().To<CustomProfileProvider>();
        ninjectKernel.Bind<ICompanyProvider>().To<CompanyProvider>();
        ninjectKernel.Bind<CustomProfile>().ToMethod(context => /*try to get here the current session and the custom profile, or build a new instance */ );
    }
}

public class NinjectControllerFactory : DefaultControllerFactory
{
    private readonly IKernel ninjectKernel;

    public NinjectControllerFactory(IKernel kernel)
    {
        ninjectKernel = kernel;
    }

    protected override IController GetControllerInstance(RequestContext requestContext,
                                                         Type controllerType)
    {
        return controllerType == null
                   ? null
                   : (IController) ninjectKernel.Get(controllerType);
    }
}

在这种情况下，您将创建此模型绑定器：

public class NinjectModelBinder: DefaultModelBinder
{
    private readonly IKernel ninjectKernel;

    public NinjectModelBinder(IKernel kernel)
    {
        ninjectKernel = kernel;
    }

    protected override object CreateModel(ControllerContext controllerContext,
                                         ModelBindingContext bindingContext,
                                         Type modelType)
    {
        return ninjectKernel.Get(modelType) ?? base.CreateModel(controllerContext, bindingContext, modelType)
    }
}

您可以将global.asax更新为：

IKernel kernel = NinjectBootStrapper.GetKernel();
ControllerBuilder.Current.SetControllerFactory(new NinjectControllerFactory(kernel));
ModelBinders.Binders.DefaultBinder = new NinjectModelBinder(kernel);

使模型绑定适用于没有默认构造函数的模型

1 个答案: