问题
I'm new to entity framework. I've got EF 4.2, from NuGet. Now I'm hearing it would be good to get DbContext. I've got into the extension manager and tried finding it, but I see about 8 there. Which is the "righ" one? I don't know if this matters but I use both C# and VB.NET. Also, I don't know if this matters or not, but I'm using a data-first model, not a code-first or model-first models, for doing EF development.
回答1:
On your EDMX design surface, right-click and pick Add Code-Generation Item:
Pick the ADO.NET DbContext Generator from the online gallery:
This adds two T4 template files (*.tt) in your solution explorer, and generates the DbContext and the entity classes for you:
And this is the resulting class derived from DbContext for your own project:
来源：https://stackoverflow.com/questions/9040396/what-dbcontext-project-do-i-get-to-work-with-ef