C# 获取当前操作系统是32位还是64位

注：判断整型的长度的方式，只有在AnyCPU编译模式下才有用。因此更好的办法是获取真的地址总线位宽（使用WMI，windows management instruementation）。

.NET 2.0

add reference, System.Management

using System.Management;
...

        public static int GetOSBit()
        {
            try
            {
                string addressWidth = String.Empty;
                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();
                foreach (ManagementObject mObject in mObjectCollection)
                {
                    addressWidth = mObject["AddressWidth"].ToString();
                }
                return Int32.Parse(addressWidth);
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
                return 32;
            }
        }