using System;  using System.Collections.Generic;  using System.Text;  using System.Windows.Forms;  using System.Data;  using System.Text.RegularExpressions;  ///  using MySql.Data.MySqlClient;          namespace NameSpace  {      class MysqlConnection      {          MySqlConnection mysqlConnection;          DataSet dataSet;          string IP = null;          string UserName = "root";          string Password = "root";          string Database = null;              public MysqlConnection()          {              try              {                  mysqlConnection = new MySqlConnection("datasource=20.0.0.20;username=root;password=root;database=sysinfo;charset=gb2312");              }              catch (MySqlException ex)              {                  MessageBox.Show(ex.Message);              }          }              public MysqlConnection(string IP,string UserName,string Password,string Database)          {              try              {                  string connectionString = "datasource=" + IP + ";username="+UserName+";password="+Password+";database=" + Database+ ";charset=gb2312" ;                  mysqlConnection = new MySqlConnection(connectionString);              }              catch (MySqlException ex)              {                  MessageBox.Show(ex.Message);              }          }              public string MysqlInfo()          {              string mysqlInfo = null;              try              {                  mysqlConnection.Open();                  mysqlInfo += "Connection Opened." + Environment.NewLine;                  mysqlInfo += "Connection String:" + mysqlConnection.ConnectionString.ToString() + Environment.NewLine;                  mysqlInfo += "Database:" + mysqlConnection.Database.ToString() + Environment.NewLine;                  mysqlInfo += "Connection ServerVersion:" + mysqlConnection.ServerVersion.ToString() + Environment.NewLine;                  mysqlInfo += "Connection State:" + mysqlConnection.State.ToString() + Environment.NewLine;              }              catch (MySqlException ex)              {                  Console.WriteLine("MySqlException Error:" + ex.ToString());              }              finally              {                  mysqlConnection.Close();              }              return mysqlInfo;          }              public int MysqlCommand(string MysqlCommand)          {              try              {                  mysqlConnection.Open();                  Console.WriteLine("MysqlConnection Opened.");                  MySqlCommand mysqlCommand = new MySqlCommand(MysqlCommand, mysqlConnection);                  return mysqlCommand.ExecuteNonQuery();              }              catch (MySqlException ex)              {                  Console.WriteLine("MySqlException Error:" + ex.ToString());                  if (Regex.IsMatch(ex.ToString(), ""))                  {                      MessageBox.Show("数据库已经存在唯一键值");                  }              }              finally              {                  mysqlConnection.Close();              }              return -1;          }              //          public DataView MysqlDataAdapter(string table)          {              DataView dataView = new DataView();              try              {                  mysqlConnection.Open();                  MySqlDataAdapter mysqlDataAdapter = new MySqlDataAdapter("Select * from " + table, mysqlConnection);                  dataSet = new DataSet();                  mysqlDataAdapter.Fill(dataSet, table);                  dataView = dataSet.Tables[table].DefaultView;              }              catch (MySqlException ex)              {                  MessageBox.Show(ex.Message);              }              finally              {                  mysqlConnection.Close();              }              return dataView;          }      }//end class  }