c＃实体框架“无法解析符号”

Question

I created a sample project using entity framework 4. It was fairly simple, I created a new data model by choosing EF Designer from database. Created the data connection and selected all tables from my database. It seems fine - I am able to see the tables in the designer.

The problem is that then I can't add or delete objects. My db class looks like that:

namespace DBAccess
{
    public class DatabaseAccess : IDisposable
    {
        private MyDBModel dbModel;

        public DatabaseAccess ()
        {
            dbModel= new MyDBModel();
        }

        public Accounts AddAccount()
        {
            var A = new Accounts();
            dbModel.Accounts.AddObject(a); // here's the "Cannot resolve symbol 'AddObject'" error
        }

        public void DeleteAccount(Accounts a)
        {
            dbModel.DeleteObject(a); // here's the "Cannot resolve symbol 'DeleteObject'" error
        }
    }
}

Why can't I use these methods? I've used them before in other projects..

This is the connection string in the App.config file:

<connectionStrings>
<add name="MyDBModel" connectionString="metadata=res://*/MyDBModel.csdl|res://*/MyDBModel.ssdl|res://*/MyDBModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=MyServer;initial catalog=MyDB;persist security info=True;user id=MyUser;password=MyPassword;MultipleActiveResultSets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />
</connectionStrings>

Answer 1

Okay, I found a solution, although I'm not sure if it's the right one..

I found this article on Microsoft's website http://msdn.microsoft.com/en-us/data/jj556581.aspx

The settings on my data model were different. In Code Generation Strategy I have T4 and Legacy ObjectContext . It was set to T4 and I changed it to Legacy ObjectContext . Then under the .edmx file I delete the two files with .tt extensions. In my case they were MyDBModel.Context.tt and MyDBModel.tt .

Rebuilt the whole solution and it works now.

I hope it will help to someone.