<system.diagnostics><switches><add name="ConnectionPoolPerformanceCounterDetail" value="4"/></switches>
</system.diagnostics>

using System;
using System.Diagnostics;
using System.Threading;namespace TestApplication
{public class Program{static void Main(string[] args){Console.WriteLine(GetPerfCount("Process", "% Processor Time", "_Total"));Console.WriteLine(GetPerfCount(".NET CLR Memory", "# Bytes in all Heaps", "_Global_"));Console.WriteLine(GetPerfCount("SQLServer:General Statistics", "User Connections"));Console.Read();}/// <summary>/// 获取计数器样本并为其返回计算所得值--有实例的计数器(对于大多数的计数器)/// </summary>/// <param name="categoryName"></param>/// <param name="counterName"></param>/// <param name="instance"></param>/// <returns></returns>public static float GetPerfCount(string categoryName, string counterName, string instance){PerformanceCounter counter = new PerformanceCounter{CategoryName = categoryName,CounterName = counterName,InstanceName = instance,MachineName = ".",ReadOnly = true};counter.NextValue();Thread.Sleep(200);try{if (counter != null){return counter.NextValue();}}catch (Exception){return -2f;}return -1f;}/// <summary>/// 获取计数器样本并为其返回计算所得值--无实例的计数器/// 比如categoryName=SQLServer:General Statistics，counterName=User Connections/// </summary>/// <param name="categoryName"></param>/// <param name="counterName"></param>/// <returns></returns>public static float GetPerfCount(string categoryName, string counterName){PerformanceCounter counter = new PerformanceCounter{CategoryName = categoryName,CounterName = counterName};counter.NextValue();Thread.Sleep(200);try{if (counter != null){return counter.NextValue();}}catch (Exception){return -2f;}return -1f;}}
}