c# 物理内存大小 Windows可见内存大小 内存信息

转自http://blog.csdn.net/zxkid/archive/2006/11/21/1401421.aspx
十分感谢 zxkid　写的这篇文章。

记得要加入System.Management命名空间，在解决方案中另击选择添加引用，在弹出的对话框中找到即可

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Management;

       #region 得到Windows可用物理内存大小
        string GetPhysicalMemorySize()
        ...{
            //PhysicalMemorySize 可用物理内存大小,与资源管理器中的关于对话框显示的内存大小一致
            //FreePhysicalMemory 剩余物理内存大小
            ulong PhysicalMemorySize = 0, VirtualMemorySize = 0, FreePhysicalMemory = 0;
            调用方式一#region 调用方式一
            //ManagementObjectSearcher seacher = new ManagementObjectSearcher("Select * From Win32_OperatingSystem");
            //foreach (ManagementBaseObject obj in seacher.Get())
            //{
            //     if (obj["TotalVisibleMemorySize"] != null)
            //         PhysicalMemorySize = (ulong)obj["TotalVisibleMemorySize"];

            //     if (obj["TotalVirtualMemorySize"] != null)
            //         VirtualMemorySize = (ulong)obj["TotalVirtualMemorySize"];

            //     if (obj["FreePhysicalMemory"] != null)
            //         FreePhysicalMemory = (ulong)obj["FreePhysicalMemory"];
            //     break;
            //}
            #endregion
            调用方式二#region 调用方式二
             ManagementClass osClass = new ManagementClass("Win32_OperatingSystem");
            foreach (ManagementObject obj in osClass.GetInstances())
            ...{
                if (obj["TotalVisibleMemorySize"] != null)
                     PhysicalMemorySize = (ulong)obj["TotalVisibleMemorySize"];

                if (obj["TotalVirtualMemorySize"] != null)
                     VirtualMemorySize = (ulong)obj["TotalVirtualMemorySize"];

                if (obj["FreePhysicalMemory"] != null)
                     FreePhysicalMemory = (ulong)obj["FreePhysicalMemory"];
                break;
             }
            #endregion

            if (PhysicalMemorySize > 0)
                return string.Format("{0:###,###,###} KB", PhysicalMemorySize);
            else
                return "Unknown";
         }
        #endregion
得到Windows可用物理内存大小

得到物理内存的大小的代码如下：
        #region 得到物理内存信息
        string GetPhysicalMemory()