在MVC项目中使用Ninject
項(xiàng)目結(jié)構(gòu)圖:
App_start文件夾中的文件是VS自己創(chuàng)建的,其中NinjectWebCommon類在創(chuàng)建之初并不存在。后面會(huì)再次提到!
添加一個(gè)Home控制器。代碼如下:
using EssentialTools.Models; using Ninject; using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc;namespace EssentialTools.Controllers {public class HomeController : Controller{private IValueCalculator calc;Product[] products ={new Product{Name="Kayak",Category="Watersports",Price=275M},new Product{Name="LifeJacket",Category="Watersports",Price=48.95M},new Product{Name="Soccer Ball",Category="Soccer",Price=19.50M},new Product{Name="Corner Flag",Category="Soccer",Price=34.95M}};public HomeController(IValueCalculator calcParam){calc = calcParam;}public ActionResult Index(){ //IKernel ninjectKernel = new StandardKernel();//ninjectKernel.Bind<IValueCalculator>().To<LinqValueCalculator>();//LinqValueCalculator calc = new LinqValueCalculator();//return View(calc.ValueProducts(products));ShoppingCart cart = new ShoppingCart(calc) { Products = products };decimal totalValue = cart.CalculateProductTotal();return View(totalValue);}} } HomeController.cs為控制器中的Index方法添加視圖。代碼如下:
@model decimal @{ViewBag.Title = "Index";Layout = null; }<div> Total value is $@Model</div> Index.cshtml創(chuàng)建Infrastructure文件夾,在該文件夾下創(chuàng)建Ninject的依賴解析器。代碼如下:
using EssentialTools.Models; using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; using Ninject;namespace EssentialTools.Infrastructure {public class NinjectDependencyResolver : IDependencyResolver{private IKernel kernel;public NinjectDependencyResolver(IKernel knernelParam){kernel = knernelParam;AddBindings();}public object GetService(Type serviceType){return kernel.TryGet(serviceType);}public IEnumerable<object> GetServices(Type serviceType){return kernel.GetAll(serviceType);}private void AddBindings(){kernel.Bind<IValueCalculator>().To<LinqValueCalculator>();}} } NinjectDependencyResolver.cs在Models文件夾中攢關(guān)鍵1個(gè)接口,3個(gè)類。代碼如下:
using System; using System.Collections.Generic; using System.Linq; using System.Web;namespace EssentialTools.Models {public interface IValueCalculator{decimal ValueProducts(IEnumerable<Product> products);} } IValueCalculator.cs using System; using System.Collections.Generic; using System.Linq; using System.Web;namespace EssentialTools.Models {public class LinqValueCalculator : IValueCalculator{public decimal ValueProducts(IEnumerable<Product> products){return products.Sum(p => p.Price);}} } LinqValueCalculator.cs using System; using System.Collections.Generic; using System.Linq; using System.Web;namespace EssentialTools.Models {public class Product{public int ProductID { get; set; }public string Name { get; set; }public string Description { get; set; }public decimal Price { get; set; }public string Category { get; set; }} } Product.cs using System; using System.Collections.Generic; using System.Linq; using System.Web;namespace EssentialTools.Models {public class ShoppingCart{IValueCalculator calc;public ShoppingCart(IValueCalculator calcParam){calc = calcParam;}public IEnumerable<Product> Products { get; set; }public decimal CalculateProductTotal(){return calc.ValueProducts(Products);}} } ShoppingCart.cs使用nuget安裝Ninject
工具→庫(kù)程序包管理器→程序包管理器控制臺(tái)
安裝ninject內(nèi)核包:
install-package Ninject -version 3.0.1.10
安裝ninject內(nèi)核包的拓展包:
install-package Ninject.Web.Common -version 3.0.0.7
對(duì)MVC3的引用(在mvc5中仍能用到)
install-package ninject.mvc3 -version 3.0.0.6
版本號(hào)最好帶上,不帶版本號(hào),可能會(huì)出錯(cuò)!
安裝好了之后NinjectWebCommon.cs文件就會(huì)出現(xiàn)。這時(shí)候需要為該類中的RegisterServices方法添加代碼(注冊(cè)依賴解析器)
RegisterServices方法代碼如下:
private static void RegisterServices(IKernel kernel){System.Web.Mvc.DependencyResolver.SetResolver(new EssentialTools.Infrastructure.NinjectDependencyResolver(kernel));} RegisterServices方法代碼?
對(duì)瀏覽器發(fā)出請(qǐng)求到控制器處理請(qǐng)求這段時(shí)間發(fā)生的事!
1、瀏覽器向MVC框架發(fā)送一個(gè)請(qǐng)求Home的URL,MVC框架推測(cè)出該請(qǐng)求意指Home控制器,于是會(huì)創(chuàng)建HomeController類實(shí)例。
2、MVC框架在創(chuàng)建HomeController類實(shí)例過(guò)程中會(huì)發(fā)現(xiàn)其構(gòu)造器有一個(gè)對(duì)IValueCalculator接口的依賴項(xiàng),于是會(huì)要求依賴項(xiàng)解析器對(duì)此依賴項(xiàng)進(jìn)行解析,?將該接口指定為依賴項(xiàng)解析器中的GetService方法所使用的類型參數(shù)。
3、依賴項(xiàng)解析器會(huì)將傳遞過(guò)來(lái)的類型參數(shù)交給TryGet方法,要求Ninject創(chuàng)建一個(gè)新的HomeController接口實(shí)例。
4、Ninect會(huì)檢測(cè)到HomeController構(gòu)造器與其實(shí)現(xiàn)類LilnqValueCalculator具有綁定關(guān)系,于是為該接口創(chuàng)建一個(gè)LinqValueCalculator類實(shí)例,并將其回遞給依賴項(xiàng)解析器。
5、依賴項(xiàng)解析器將Ninject所返回的LilnqValueCalculator類作為IValueCalculator接口實(shí)現(xiàn)類實(shí)例回遞給MVC框架
6、MVC框架利用依賴項(xiàng)解析器返回的接口類實(shí)例創(chuàng)建HomeController控制器實(shí)例,并使用該控制器實(shí)例對(duì)請(qǐng)求進(jìn)行服務(wù)。
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為已經(jīng)能夠正常運(yùn)行的程序添加功能:為購(gòu)物車內(nèi)的東西打折。
在Models文件夾內(nèi)添加一個(gè)叫做Discount的類
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using System; using System.Collections.Generic; using System.Linq; using System.Web;namespace EssentialTools.Models {public interface IDiscountHelper{decimal ApplyDiscount(decimal totalParam);}public class DefaultDiscounter : IDiscountHelper{public decimal DiscountSize { get; set; }public decimal ApplyDiscount(decimal totalParam){return (totalParam - (DiscountSize / 100m * totalParam));}} } Discount.cs?
這個(gè)類里面包涵了一個(gè)接口,沒有讓接口和類進(jìn)行分離(當(dāng)然,這不是重點(diǎn))。
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更改后的計(jì)算價(jià)格的類LinqValueCalculator
using System; using System.Collections.Generic; using System.Linq; using System.Web;namespace EssentialTools.Models {public class LinqValueCalculator : IValueCalculator{private IDiscountHelper discounter;public LinqValueCalculator(IDiscountHelper discountParam){discounter = discountParam;}public decimal ValueProducts(IEnumerable<Product> products){return discounter.ApplyDiscount(products.Sum(p => p.Price));}} } LinqValueCalculator.cs最后更改依賴項(xiàng)解析器類中的AddBindings方法
private void AddBindings(){kernel.Bind<IValueCalculator>().To<LinqValueCalculator>();kernel.Bind<IDiscountHelper>().To<DefaultDiscounter>().WithPropertyValue("DiscountSize", 50M);}在Discount類中,有一個(gè)DiscountSize的屬性,上面方法中使用了WithPropertyValue方法為這個(gè)屬性賦了初始值。
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轉(zhuǎn)載于:https://www.cnblogs.com/vichin/p/8595371.html
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