最近做了一个项目，需要获取机器的CPU和memory的使用情况。花了一些时间网上搜索了一下，自己也做了些测试。总结下来，基本上2种方式：一种是用WMI（2种），另一种是用Performance counter。

1. Use WMI to create connection to the computer passing username and password. Once the connection is created,  query the CPU& memory by passing the query, similar as SQL.  This way can get CPU & memory for remote PC and local PC. For example:

System.Management.ConnectionOptions Conn = new ConnectionOptions();

Conn.Username = mpusername;

Conn.Password = mppwd;

string scopestring = "//" + mpserver + "/root/cimv2";

System.Management.ManagementScope Ms = new ManagementScope(scopestring);

Ms.Connect();

mos.Scope = Ms;

ObjectQuery oq = new ObjectQuery();

oq.QueryString = "select * from Win32_Processor";

mos.Query = oq;

ManagementObjectCollection moc = mos.Get();

内存这块花了比较多的时间，之前的对象已经过期，不能使用了，最后找到这个类“Win32_PerfRawData_PerfOS_Memory”

ManagementObjectCollection mcr = mcp.getQueryResult("select * from Win32_ComputerSystem");
           
            foreach (ManagementObject mo in mcr)
            {
                if (mo["TotalPhysicalMemory"] != null)
                {
                    totalm = long.Parse(mo["TotalPhysicalMemory"].ToString());
                }
            }
            ManagementObjectCollection moc = mcp.getQueryResult("select * from Win32_PerfRawData_PerfOS_Memory");
            foreach (ManagementObject mo in moc)
            {
                string avilable = mo.GetPropertyValue("AvailableBytes").ToString();
                avilablem = long.Parse(avilable);
            }

2. Get local server’s CPU and momory information passing the WMI classes, such as “Win32_Processor”， “Win32_OperatingSystem”

ManagementClass mc = new ManagementClass("Win32_OperatingSystem");

ManagementObjectCollection moc = mc.GetInstances();

3. Use performance counter to get performance data passing the performance counter name, such as monitor.PerformanceCounterFun("Processor", "_Total", "% Processor Time"). Normally we shoud get performance counter data several times, then use the average values.

虽然这些比较简单，但是自己还是想把它记录下来，希望对大家能有用！