Entity Framework DbContext dynamic instantiation with custom Connection String

问题

Migrating from ObjectContext to DbContext code-generation, I realized that context class generated (which inherits from DbContext) has no constructor that receives connectionString neither EntityConnection (like ObjectContext child class had).

This is a problem in my application since I need to instantiate my context dynamically from the concrete Type, using a runtime generated connection string.

回答1:

On your class that inherits the DbContext, you should be able to specify the base constructor that takes the connection sting:

public class MyDbContext : DbContext
{
    public MyDbContext(string connString)
        : base(connString)
    {
    }
}

You will have to use the SQLConnection builder though:

SqlConnectionStringBuilder connBuilder= new SqlConnectionStringBuilder(dbConnString);

And use it in your constructor:

MyDbContext dbContext = new MyDbContext(connBuilder.ToString());

回答2:

This helped me:

 public MyDatabaseContext():base("name=MyConnectionString")
  {
  }

来源：https://stackoverflow.com/questions/16341163/entity-framework-dbcontext-dynamic-instantiation-with-custom-connection-string