在Visual Studio 2012中打开的asp.net mvc3应用程序，无法找到程序集“EntityFramework”

Question

I opened and edited an ASP.NET MVC 3 application developed in Visual Studio 2010, in Visual Studio 2012. It was working fine in Debug mode but when I tried to publish it (release mode), it failed and threw following warnings and errors.

C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1605,5): warning MSB3245: Could not resolve this reference. Could not locate the assembly "EntityFramework". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors.

error CS0234: The type or namespace name 'Infrastructure' does not exist in the namespace 'System.Data.Entity' (are you missing an assembly reference?)

error CS0246: The type or namespace name 'DbContext' could not be found (are you missing a using directive or an assembly reference?)

error CS0246: The type or namespace name 'DbModelBuilder' could not be found (are you missing a using directive or an assembly reference?)

error CS0246: The type or namespace name 'DbSet' could not be found (are you missing a using directive or an assembly reference?)

EntityFramework.dll is present in bin folder and EntityFramework 5.0 is installed. Can this be resolved ?

What am I doing wrong while migrating this project? Microsoft says no modifications are needed when going from VS 2010 to VS 2012 http://msdn.microsoft.com/en-us/library/vstudio/jj161050.aspx#ASP .

Answer 1

If there is a file called packages.config in the project, open it and remove the reference to EntityFramework (something like <package id="EntityFramework" ... /> ). Also remove the reference to the assembly from the project (select the assembly under 'References' and delete it) and remove the assembly from the bin folder.

Now you can reinstall the package using the package manager (right click the project and select "Manage NuGet Packages").