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 ;
}
}