Autofac resolving parameters in runtime - c#-4.0

Question

Let's get straight.
I have interface and class like this:
public interface IDataBase
{
DataTable GetSomeTableData();
}
My class:
public class DataBase : IDataBase
{
private readonly string _connectionString;
public DataBase(string connectionString)
{
this._connectionString = connectionString;
}
public DataTable GetSomeTableData()
{
using (SqlConnection cn = new SqlConnection(_connectionString))
{
cn.Open();
// some select
}
}
}
I'm using Autofac to inject that class:
var builder = new ContainerBuilder();
builder.RegisterType<DataBase>().As<IDataBase>).WithParameter("connectionString", "my connection string");
var container = builder.Build();
var database = container.Resolve<IDataBase>();
var tableData1 = database.GetSomeTableData();
// change connection string ?????????????????
var tableData2 = database.GetSomeTableData();
I need to get table data from one DB and another DB. How can I change connection string after have registered class? You may give another exapmle..

Answer 1

There are many ways to do it. One would be to create and inject a service instead of just plain connection string.
public interface IConnectionStringProvider
{
public string ConnectionString { get; set }
}
public class ConnectionStringProvider
{
public string ConnectionString { get; set }
}
var builder = new ContainerBuilder();
builder.RegisterType<DataBase>()
.As<IDataBase>);
builder.RegisterType<ConnectionStringProvider>)
.As<IConnectionStringProvider>
.SingleInstance();
var container = builder.Build();
var database = container.Resolve<IDataBase>();
var connStringProvider = container.Resolve<IConnectionStringProvider>();
var tableData1 = database.GetSomeTableData();
connStringProvider.ConnectionString = "...";
var tableData2 = database.GetSomeTableData();
The DataBase would then use that service:
public class DataBase : IDataBase
{
private readonly IConnectionStringProvider _connectionStringProvider;
public DataBase(IConnectionStringProvider connectionStringProvider)
{
this._connectionStringProvider = connectionStringProvider;
}
public DataTable GetSomeTableData()
{
using (SqlConnection cn = new SqlConnection(_connectionStringProvider.ConnectionString))
{
cn.Open();
// some select
}
}
}