一个简单的DBHelper

</pre><pre name="code" class="csharp">using System;
using System.Data;
using System.Configuration;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using MySql.Data;
using MySql.Data.MySqlClient;
using System.IO;
using System.Diagnostics;
using System.Windows.Forms;

namespace DAL
{
public class DBHelper
{
#region 全局变量
//定义连接字符串
private string ConString = "server=localhost; userid=root; password=123456; database=machine";
//新建连接
private MySqlConnection con;
#endregion

#region 连接数据库
//连接数据库
public MySqlConnection Connection
{
get
{
if (con == null)
{
con = new MySqlConnection(ConString);
}
return con;
}
}
#endregion

#region 打开数据库
//打开数据库
public void OpenConnection()
{
if (Connection.State == ConnectionState.Closed)
{
Connection.Open();
}
else if (Connection.State == ConnectionState.Broken)
{
Connection.Close();
Connection.Open();
}
}
#endregion

#region 关闭数据库
//关闭数据库
public void CloseConnection()
{
if (Connection.State == ConnectionState.Open || Connection.State == ConnectionState.Broken)
{
Connection.Close();
}
}

#endregion

}
}