如何判断系统是64位还是32位

　　对于C#来说，调用WMI是一种简单易行的方式。我们可以用Win32_Processor类里面的AddressWidth属性来表示系统的位宽。AddressWidth的值受CPU和操作系统的双重影响。

具体的值如下面的表格所示：

	32bit OS	64bit OS
32bit CPU	AddressWidth = 32	N/A
64bit CPU	AddressWidth = 32	AddressWidth = 64

可以用下面的C#代码得到AddressWidth的值(引用System.Management.dll)：

using System.Managment;

/// <summary>
        /// 检查系统是32位还是64位
        /// </summary>
        /// <returns>0运行出错;32表示32位系统;64表示64位操作系统</returns>
        public static int Distinguish64or32System()
        {
            try
            {
                //得到AddressWidth值
                ConnectionOptions mConnOption = new ConnectionOptions();
                ManagementScope mMs = new ManagementScope("\\\\localhost", mConnOption);
                ObjectQuery mQuery = new ObjectQuery("select AddressWidth from Win32_Processor");
                ManagementObjectSearcher mSearcher = new ManagementObjectSearcher(mMs, mQuery);
                ManagementObjectCollection mObjectCollection = mSearcher.Get();
                string retVal = string.Empty;
                foreach (ManagementObject mObject in mObjectCollection)
                {
                    retVal = mObject["AddressWidth"].ToString();
                }

                //根据值判断,不能直接返回得到的值,
                //32位返回"32",64位会因为CPU而有两个值,"N/A"或"64"
                if (retVal == "32")
                {
                    return 32;
                }
                else
                {
                    return 64;
                }
            }
            catch
            {
                return 0;
            }
        }