How to keep some information secure and use it from behind private procedure

This code is work how can I keep user name and password secure and can use from many code so when i change password then i can change one page and effect to many code

using System;
using System.Data;
using MySql.Data;
using MySql.Data.MySqlClient;

namespace ExportXMLData
{
  class ExportXML
  {
    static void Main(string[] args)
    {
      ExportXML exportXML = new ExportXML();
   开发者_如何学C   exportXML.Run();
    }

    private void Run()
    {
      // Change the variables to reflect values needed for
      // your computer and database properties.
      string Database = "";
      string Server = "localhost";
      string User = "";
      string Pass = "";
      string TableName = "";
      string XMLRootNodeName = "Root";
      string OutputFileName = "output.xml";

      string conn = 
    "Database=" + Database + ";" + 
    "Server=" + Server + ";" +
    "Uid=" + User + ";" +
    "Pwd=" + Pass;

      MySqlConnection connection = new MySqlConnection(conn);
      MySqlDataAdapter adapter = new MySqlDataAdapter();
      adapter.TableMappings.Add("Table", TableName);
      connection.Open();
      MySqlCommand query = new MySqlCommand("SELECT * FROM "
                        + TableName, connection);
      query.CommandType = CommandType.Text;
      adapter.SelectCommand = query;
      DataSet ds = new DataSet(XMLRootNodeName);
      adapter.Fill(ds);
      connection.Close();

      ds.WriteXml(OutputFileName, XmlWriteMode.WriteSchema);
    }
  }
}

Just make the 'User' and 'Pass' variables into properties on the 'ExportXML' class.

It's depending to architecture. Where you want to have this access. You can declare private string Pass in your class and use for example Friend assemblies to access an internal member of a public classes.