In the light of Closing connections explicitly in Entity Framework and http://msdn.microsoft.com/en-us/library/bb738582%28v=vs.90%29.aspx it seems that I should be using the con
If the EF connection string is stored in your web config file, you can assign it to a SQL Data Source with this code:
var connString = ConfigurationManager.ConnectionStrings["MyDataEntities"].ConnectionString;
EntityConnection ec = new EntityConnection(connString);
var storeConnect = ec.StoreConnection;
SqlDataSource1.ConnectionString = storeConnect.ConnectionString;