利用反射工厂来产生对象

public class InstanceFactory
{
public static DBFactory Instance(string InstanceType)
{
Type t = Type.GetType(InstanceType);
DBFactory DBInstance = (DBFactory)Activator.CreateInstance(t);
return DBInstance;
}
}

public static void Main()
{

DBFactory db = InstanceFactory.Instance("Project1.sqlserver");
DBOperator dbo = new DBOperator(db);
dbo.Open("server=MS124716;database=test;uid=sa;pwd=12");
DataTable dt = dbo.ExecSQL("select * from login");
foreach (DataRow dr in dt.Rows)
{
Console.Write(dr["name"].ToString());
Console.Write(dr["pwd"].ToString());
}

Console.Read();

}