数据访问层有一个类，负责管理数据并与Presenter通信。
public interface ILibraryDataManager
{
//some code...
}
public class LibraryDataManager:ILibraryDataManager
{
//some code...
}
实现一个原始版本，不要过多关注细节... 接下来，在主项目中实现以下类： MessageService - 能够在程序的任何地方显示消息
interface IMessageService
{
//some code
}
class MessageService : IMessageService
{
//some code
}
LoginService和MainService - 日志实现逻辑和应用程序的基本功能
public interface ILoginService
{
//some code
}
class LoginService : ILoginService
{
private readonly IMessageService messageServise;
private readonly ILibraryDataManager libraryDBManger;
public LoginService(IMessageService messageServise, ILibraryDataManager libraryDataManager)
{
this.messageServise = messageServise;
this.libraryDBManger = libraryDataManager;
}
//some code...
}
public interface IMainService
{
//some code
}
class MainService : IMainService
{
private readonly IMessageService messageService;
private readonly ILibraryDataManager libraryDBManger;
public MainService(ILibraryDataManager libraryDataManager, IMessageService messageService)
{
this.libraryDBManger = libraryDataManager;
this.messageService = messageService;
}
//some code...
}
此外，分别有IView接口及其派生接口和实现它们的类：
public interface IView
{
//some code...
}
public interface ILoginView: IView
{
//some code...
}
public partial class FormLogin : Form, ILoginView
{
//some code...
}
public interface IMainView: IView
{
//some code...
}
public partial class MainForm : Form, IMainView
{
//some code...
}
现在我们要介绍的是链接元素 - 展示器：
public interface IPresenter
{
void Run(); // этот метод должен запускать соответствующую форму (IView), переданную презентеру в конструкторе
}
class LoginPresenter : IPresenter
{
private readonly ILoginView loginView;
private readonly ILoginService loginService;
private readonly IMessageService messageService;
public LoginPresenter(ILoginView loginView, ILoginService loginService, IMessageService messageService)
{
this.loginView = loginView;
this.loginService = loginService;
this.messageService = messageService;
}
public void Run()
{
loginView.Show();
}
//some code...
}
class MainPresenter : IPresenter
{
private readonly IMainView mainView;
private readonly IMessageService messageService;
private readonly IMainService mainService;
public MainPresenter (IMainView mainView, IMessageService messageService, IMainService mainService)
{
this.mainService = mainService;
this.mainView = mainView;
this.messageService = messageService;
}
public void Run()
{
Application.Run(mainView as Form);
}
现在我只需要在容器中注册并尝试运行应用程序：
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
UnityContainer container = new UnityContainer();
container.RegisterType<ILibraryDataManager, LibraryDataManager>()
.RegisterType<IMessageService, MessageService>()
.RegisterType<ILoginService, LoginService>()
.RegisterType<ILoginView, FormLogin>()
.RegisterType<IMainView, MainForm>();
var obj = container.Resolve<MainPresenter>();
obj.Run();
}
}
然而，obj.Run()这一行并没有得到执行，因为在前一行发生了错误。
var obj = container.Resolve<MainPresenter>();
出现如下错误：
Microsoft.Practices.Unity.ResolutionFailedException未处理 HResult=-2146233088 Message=解析依赖项失败，类型 = “Library.MainPresenter”，名称 = “(none)”。异常出现在：正在解析时。异常为：InvalidOperationException - 当前类型Library.IMainService是一个接口，无法构造。您是否缺少类型映射？ ----------------------------------------------- 在异常发生时，容器为：
正在解析 Library.MainPresenter,(none) 正在解析构造函数参数“mainService”Library.MainPresenter(Library.IMainView mainView, Library.IMessageService messageService, Library.IMainService mainService) 正在解析 Library.IMainService,(none)
根据错误描述，我理解在创建MainPresenter并传递UnityContainer参数时，尝试创建一个接口对象，这当然是不可能的。但是我之前已经添加了“接口 - 类”到容器中并取出它，Unity必须创建相应的对象，然后将接口引用传递给它，结果会有很大不同。
抱歉我的英语表达不够流畅 : \