使用WMI来连接远端计算机

1. wmi连接前提

利用wmi来连接远端计算机首先要具有远端计算机管理员的用户名和密码。如果计算机在域中的话，要有域管理员用户名和密码，或者是把域帐户加入本机管理员组中也可以。

2. 相关类的用法--- ConnectionOptions和ManagementScope

ConnectionOptions用于设置连接选项，比如设置所连接机器的域，用户名，密码等。ManagementScope用于连接的实际操作。

   :  using System;
   :  using System.Collections.Generic;
   :  using System.Text;
   :  using System.Management;
   :
   :  namespace TJVictor.WMI
   :  {
   :      public class WMIBaseClass
   :      {
  :          #region Property
  :          private ConnectionOptions connection;
  :
  :          private ManagementScope scope;
  :          public ManagementScope Scope
  :          {
  :              get { return scope; }
  :              set { scope = value; }
  :          }
  :
  :          private string domain;
  :          public string Domain
  :          {
  :              get { return domain; }
  :              set { domain = value; }
  :          }
  :
  :          private string ip;
  :          public string Ip
  :          {
  :              get { return ip; }
  :              set { ip = value; }
  :          }
  :
  :          private string user;
  :          public string User
  :          {
  :              get { return user; }
  :              set { user = value; }
  :          }
  :
  :          private string password;
  :          public string Password
  :          {
  :              get { return password; }
  :              set { password = value; }
  :          }
  :
  :          private string nameSpace;
  :          public string NameSpace
  :          {
  :              get { return nameSpace; }
  :              set { nameSpace = value; }
  :          }
  :          #endregion
  :
  :          #region Construction
  :          public WMIBaseClass()
  :          {
  :              this.domain = string.Empty;
  :              this.ip = string.Empty;
  :              this.user = string.Empty;
  :              this.password = string.Empty;
  :              this.nameSpace = "root//cimv2";
  :          }
  :
  :          public WMIBaseClass(string ip, string user, string password)
  :          {
  :              this.domain = string.Empty;
  :              this.ip = ip;
  :              this.user = user;
  :              this.password = password;
  :              this.nameSpace = "root//cimv2";
  :          }
  :
  :          public WMIBaseClass(string domain, string ip, string user, string password)
  :          {
  :              this.domain = domain;
  :              this.ip = ip;
  :              this.user = user;
  :              this.password = password;
  :              this.nameSpace = "root//cimv2";
  :          }
  :
  :          public WMIBaseClass(string domain, string ip, string user, string password, string nameSpace)
  :          {
  :              this.domain = domain;
  :              this.ip = ip;
  :              this.user = user;
  :              this.password = password;
  :              this.nameSpace = nameSpace;
  :          }
  :          #endregion
  :
  :          #region protected function
  :          protected virtual void Connection()
  :          {
  :              this.scope = Cache.CacheClass.Get(this.ip) as ManagementScope;
  :              if (this.scope == null)
  :              {
 :                  connection = new ConnectionOptions();
 :                  if (!domain.Equals(string.Empty))
 :                      connection.Authority = "ntlmdomain:" + this.domain;
 :                  if (!user.Equals(string.Empty))
 :                      connection.Username = this.user;
 :                  if (!password.Equals(string.Empty))
 :                      connection.Password = this.password;
 :                  string temp = string.Empty;
 :                  if (ip.Equals(string.Empty))
 :                      temp = "////" + "." + "//" + this.nameSpace;////" + this.ip + "//" + this.nameSpace;
 :                  else
 :                      temp = "
:                  scope = new ManagementScope(temp, connection);
:                  if (!scope.IsConnected)
 :                      scope.Connect();
:                  Cache.CacheClass.Insert(this.ip, scope);
 :              }
 :              else
 :              {
 :                  if (!scope.IsConnected)
 :                      scope.Connect();
 :              }
 :          }
 :
 :          protected virtual void DisConnection(string key)
 :          {
 :              Cache.CacheClass.Remove(key);
 :          }
 :
 :          protected virtual ManagementObjectCollection GetSelectQueryCollection(string wqlSelect, string condition)
 :          {
 :              SelectQuery query = new SelectQuery(string.Format(wqlSelect, condition));
 :              ManagementObjectSearcher mos = new ManagementObjectSearcher(scope, query);
 :              return mos.Get();
 :          }
 :
 :          protected virtual ManagementObjectSearcher GetObjectSearcher(string wqlSelect, string condition)
 :          {
 :              SelectQuery query = new SelectQuery(string.Format(wqlSelect, condition));
 :              return new ManagementObjectSearcher(scope, query);
 :          }
 :          #endregion
 :      }
 :  }

. 代码说明

由于连接远端机器是所有wmi操作的第一步，所以我们把连接wmi作为一个基类，以后所有对wmi操作的类都继承这个类。

其中Connection()函数就是建立远端连接。其实很简单，如果只要把域、用户名、密码、IP、wmi命名空间等属性设置完成，就可以利用wmi提供的scope.Connect();来尝试连接远端机器。

Wmi中没有释放连接的函数。也就是说，当这个类被GC回收后，远端连接也就自动被释放了，否则与远端机器一直都处于连接状态。