Model.Item == Context.Item？ 
 
 正如@ Jim-Noellsch所提到的，如果您的代码基于当前上下文项运行，则默认值将与Model.Item相同。 但是，如果要构建数据源驱动的组件或使用控制器更改模型上的绑定项，则需要使用Model.Item来确保拉出绑定到模型的项，而不是上下文项。 
 
 MVC布局中的Web窗体？ 
 
 至于MVC布局中的Web表单，我不相信Sitecore支持开箱即用。 您可以查看其他人为完成类似操作而做的一些自定义（ Web表单中的MVC ）。 从本质上讲，这归结为自定义管道以允许处理不兼容的组件。 
 
 混合Sitecore解决方案 
 
 您还可以使用Web窗体中的某些页面和MVC中的某些页面构建混合站点，但这可能需要您将某些组件从一个转换为另一个。 我最近在这里写了一篇关于混合动力车的文章： http ： //www.nonlinearcreations.com/Digital/how-we-think/articles/2015/05/MVC-Web-Forms-Hybrid-Sitecore.aspx 
 
 对于混合方法，如果您需要在两种布局类型上具有类似的功能，那么是的，您将需要“重复”组件（一个子布局，一个渲染）。 这完全可以接受。 您已经拥有不同的布局和模板，这只是另一层。 您可能还在子布局中放置了一些演示业务逻辑。 您可能想要考虑将其移动到ViewModel类，然后在渲染和子布局中使用相同的类 
 
 使用ViewModel 
 
 对于Model.Item，您可以指定将成为模型对象的业务对象，而不是使用模型的标准Sitecore项。 我有一个SlideShare，可以将WebForms子布局转换为MVC渲染 。 幻灯片6显示了ViewModel实现示例，幻灯片8显示了在MVC视图中使用它。 从这里开始，您可以在子布局后面使用相同的ViewModel来集中一些逻辑。 

Model.Item == Context.Item?
 
As @Jim-Noellsch mentioned, if your code is running based on the current context item, then the default will be the same as the Model.Item. However, if you are building datasource-driven components or have altered the bound item on the model using a controller, you will want to use Model.Item to ensure you pull the item bound to the model, and not the context item.
 
Web Forms inside MVC layout?
 
As for web forms inside an MVC layout, I do not believe that Sitecore supports this out of the box. You can view some customizations that have been done by others to do something similar (MVC inside web forms). Essentially, this comes down to customizing the pipelines to allow your incompatible components to be processed.
 
Hybrid Sitecore solutions
 
You can also build a hybrid site with some pages in Web Forms and some in MVC, but this may require you to translate some of your components from one to the other. I recently wrote a post on hybrids here: http://www.nonlinearcreations.com/Digital/how-we-think/articles/2015/05/MVC-Web-Forms-Hybrid-Sitecore.aspx
 
For a hybrid approach, if you need to have similar functionality on both layout types, then yes, you will need 'duplicate' components (one sublayout, one rendering). This is completely acceptable. You already have different layouts and templates, this is just another layer. You may also have put some presentation business logic in your sublayouts. You may want to think about moving that to a ViewModel class and then using the same class in both your rendering and sublayout
 
Using ViewModel
 
For your Model.Item, instead of using a standard Sitecore Item for your Model, you can specify a business object that will be the model object instead. I have a SlideShare on converting WebForms sublayouts to MVC renderings. Slide 6 shows a ViewModel implementation example, and Slide 8 shows using it in an MVC View. From here, you could probably use the same ViewModel behind your sublayout to centralize some of your logic.