怎么实现这个功能大家肯定早都知道了，放上来是给自己留个备份 
使用：
private void button1_Click_1(object sender, System.EventArgs e)
...{
 string[] servers = DBGrep.SqlLocator.GetServers();
 foreach ( string s in servers )
 ...{
 this.listBox1.Items.Add(s);
 }
}
类的代码
using System;using System.Text;using System.Windows.Forms;using System.Runtime.InteropServices;
namespace DBGrep
...{
 public class SqlLocator
 ...{
 [DllImport("odbc32.dll")]
 private static extern short SQLAllocHandle(short hType, IntPtr inputHandle, out IntPtr outputHandle);
 [DllImport("odbc32.dll")]
 private static extern short SQLSetEnvAttr(IntPtr henv, int attribute, IntPtr valuePtr, int strLength);
 [DllImport("odbc32.dll")]
 private static extern short SQLFreeHandle(short hType, IntPtr handle);
 [DllImport("odbc32.dll",CharSet=CharSet.Ansi)]
 private static extern short SQLBrowseConnect(IntPtr hconn, StringBuilder inString,
 short inStringLength, StringBuilder outString, short outStringLength,
 out short outLengthNeeded);
 private const short SQL_HANDLE_ENV = 1;
 private const short SQL_HANDLE_DBC = 2;
 private const int SQL_ATTR_ODBC_VERSION = 200;
 private const int SQL_OV_ODBC3 = 3;
 private const short SQL_SUCCESS = 0;
 private const short SQL_NEED_DATA = 99;
 private const short DEFAULT_RESULT_SIZE = 1024;
 private const string SQL_DRIVER_STR = "DRIVER=SQL SERVER";
 private SqlLocator()...{}
 public static string[] GetServers()
 ...{
 string[] retval = null;
 string txt = string.Empty;
 IntPtr henv = IntPtr.Zero;
 IntPtr hconn = IntPtr.Zero;
 StringBuilder inString = new StringBuilder(SQL_DRIVER_STR);
 StringBuilder outString = new StringBuilder(DEFAULT_RESULT_SIZE);
 short inStringLength = (short) inString.Length;
 short lenNeeded = 0;
 try
 ...{
 if (SQL_SUCCESS == SQLAllocHandle(SQL_HANDLE_ENV, henv, out henv))
 ...{
 if (SQL_SUCCESS == SQLSetEnvAttr(henv,SQL_ATTR_ODBC_VERSION,(IntPtr)SQL_OV_ODBC3,0))
 ...{
 if (SQL_SUCCESS == SQLAllocHandle(SQL_HANDLE_DBC, henv, out hconn))
 ...{
 if (SQL_NEED_DATA == SQLBrowseConnect(hconn, inString, inStringLength, outString,
 DEFAULT_RESULT_SIZE, out lenNeeded))
 ...{
 if (DEFAULT_RESULT_SIZE < lenNeeded)
 ...{
 outString.Capacity = lenNeeded;
 if (SQL_NEED_DATA != SQLBrowseConnect(hconn, inString, inStringLength, outString,
 lenNeeded,out lenNeeded))
 ...{
 throw new ApplicationException("Unabled to aquire SQL Servers from ODBC driver.");
 }
 }
 txt = outString.ToString();
 int start = txt.IndexOf("{") + 1;
 int len = txt.IndexOf("}") - start;
 if ((start > 0) && (len > 0))
 ...{
 txt = txt.Substring(start,len);
 }
 else
 ...{
 txt = string.Empty;
 }
 }
 }
 }
 }
 }
 catch (Exception ex)
 ...{
 //Throw away any error if we are not in debug mode
#if (DEBUG)
 MessageBox.Show(ex.Message,"Acquire SQL Servier List Error");
#endif
 txt = string.Empty;
 }
 finally
 ...{
 if (hconn != IntPtr.Zero)
 ...{
 SQLFreeHandle(SQL_HANDLE_DBC,hconn);
 }
 if (henv != IntPtr.Zero)
 ...{
 SQLFreeHandle(SQL_HANDLE_ENV,hconn);
 }
 }
 if (txt.Length > 0)
 ...{
 retval = txt.Split(",".ToCharArray());
 }
 return retval;
 }
 }
}