试工厂模式连数据库，帮看看哪里问题
using System;
using System.Data;
using System.Data.Common;
using System.Windows.Forms;


namespace ConsoleApplication1
{
  class Program
  {  
  [STAThread]
  static void Main(string[] args)
  {
  System.Windows.Forms.OpenFileDialog openFileDialog1 = new System.Windows.Forms.OpenFileDialog();
  openFileDialog1.Filter = "数据库 (*.mdb)|*.mdb";
  openFileDialog1.ShowDialog();
  String accessname = openFileDialog1.FileName;

  String contype = "System.Data.OleDb";
  String conStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + accessname + ";User ID=Admin;Password=;";

  try
  {

  DbProviderFactory factory = DbProviderFactories.GetFactory(contype);
  DbConnection con = factory.CreateConnection();
  //到这步连接报错未被捕捉到，连接未正常建立，正确写法该如何改ServerVersion “con.ServerVersion”引发了“System.InvalidOperationException”类型的异常 string {System.InvalidOperationException}
  con.ConnectionString = conStr;
  DbCommand cmd = factory.CreateCommand();
   
  cmd.Connection = con;
  DbDataAdapter dapter = factory.CreateDataAdapter();
  }
  catch (System.InvalidOperationException e)//ClassNotFoundException e)
  { //捕获驱动类无法找到异常
  //throw e; //e.printStackTrace();
  System.Diagnostics.Trace.Assert(false, e.Message, "");
  System.Environment.Exit(0);
  }
  }
  }
}

------解决方案--------------------
USING OLEDB....
这里是不是都是高手....