如何使用MVVMLight SimpleIoc？

Question

我正在对软件进行升级，该软件有些混乱Messenger.Default(...)。

是否有任何备忘单来了解MVVMLight SimpleIoc的用法（不是一般的IoC描述）？

Answer 1

SimpleIoc婴儿床床单：1）您在ViewModelLocator中注册了所有接口和对象class ViewModelLocator&nbsp;{&nbsp;&nbsp; &nbsp; static ViewModelLocator()&nbsp;&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; ServiceLocator.SetLocatorProvider(() => SimpleIoc.Default);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; if (ViewModelBase.IsInDesignModeStatic)&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; SimpleIoc.Default.Register<IDataService, Design.DesignDataService>();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; else&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; SimpleIoc.Default.Register<IDataService, DataService>();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; SimpleIoc.Default.Register<MainViewModel>();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; SimpleIoc.Default.Register<SecondViewModel>();&nbsp;&nbsp; &nbsp; }&nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; public MainViewModel Main&nbsp;&nbsp; &nbsp; {&nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; get&nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return ServiceLocator.Current.GetInstance<MainViewModel>();&nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp;&nbsp; &nbsp; }}&nbsp;2）默认情况下，每个对象都是单例。要解析对象以使其不是单例，您需要将唯一值传递给GetInstance调用：SimpleIoc.Default.GetInstance<MainViewModel>(Guid.NewGuid().ToString());3）要针对接口注册类：SimpleIoc.Default.Register<IDataService, Design.DesignDataService>();&nbsp;&nbsp;4）要针对接口注册具体对象：SimpleIoc.Default.Register<IDataService>(myObject);&nbsp; &nbsp; &nbsp;5）要注册具体类型：SimpleIoc.Default.Register<MainViewModel>();&nbsp; &nbsp;6）要从接口解析对象：SimpleIoc.Default.GetInstance<IDataService>();7）直接解析对象（建立和依赖关系解析）：SimpleIoc.Default.GetInstance<MainViewModel>();8）MVVM使设计时数据的确非常容易：if (ViewModelBase.IsInDesignModeStatic)&nbsp;{&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; SimpleIoc.Default.Register<IDataService, Design.DesignDataService>();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;}&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;else&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;{&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; SimpleIoc.Default.Register<IDataService, DataService>();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;}&nbsp;&nbsp;如果您处于设计时模式，它将自动注册您的设计时服务，这使得在VS设计器中工作时在视图模型和视图中存储数据变得非常容易。希望这可以帮助。

Answer 2

1）我发现SimpleIoc抛出设计时异常，因为服务已经注册。如果我检查IsRegistered，然后在我的视图模型中引用SimpleIoc，则不会显示设计时数据（不会引发异常，只是不显示）。如果删除SimpleIoc并手动创建数据，那么它将在设计时显示出来。因此，不，我认为这“真的很简单” :)请注意，数据服务在设计时间之外工作良好。