下面是c#中使用DllImport的直接方法。

[DllImport("kernel32.dll", SetLastError = true, CallingConvention = CallingConvention.Winapi)] 
[return: MarshalAs(UnmanagedType.Bool)] 
public static extern bool IsWow64Process([In] IntPtr hProcess, [Out] out bool lpSystemInfo); 

public static bool Is64Bit() 
{ 
    bool retVal; 

    IsWow64Process(Process.GetCurrentProcess().Handle, out retVal); 

    return retVal; 
} 

这只是Bruno Lopez上面建议的一个实现，但适用于Win2k +所有的WinXP服务包。我只是想把它贴出来这样别人就不用亲手卷了。(本可以作为评论发布，但我是一个新用户!)

[DllImport("kernel32", SetLastError = true, CallingConvention = CallingConvention.Winapi)]
public extern static IntPtr LoadLibrary(string libraryName);

[DllImport("kernel32", SetLastError = true, CallingConvention = CallingConvention.Winapi)]
public extern static IntPtr GetProcAddress(IntPtr hwnd, string procedureName);

private delegate bool IsWow64ProcessDelegate([In] IntPtr handle, [Out] out bool isWow64Process);

public static bool IsOS64Bit()
{
    if (IntPtr.Size == 8 || (IntPtr.Size == 4 && Is32BitProcessOn64BitProcessor()))
    {
        return true;
    }
    else
    {
        return false;
    }
}

private static IsWow64ProcessDelegate GetIsWow64ProcessDelegate()
{
  IntPtr handle = LoadLibrary("kernel32");

  if ( handle != IntPtr.Zero)
  {
    IntPtr fnPtr = GetProcAddress(handle, "IsWow64Process");

    if (fnPtr != IntPtr.Zero)
    {
      return (IsWow64ProcessDelegate)Marshal.GetDelegateForFunctionPointer((IntPtr)fnPtr, typeof(IsWow64ProcessDelegate));
    }
  }

  return null;
}

private static bool Is32BitProcessOn64BitProcessor()
{
  IsWow64ProcessDelegate fnDelegate = GetIsWow64ProcessDelegate();

  if (fnDelegate == null)
  {
    return false;
  }

  bool isWow64;
  bool retVal = fnDelegate.Invoke(Process.GetCurrentProcess().Handle, out isWow64);

  if (retVal == false)
  {
    return false;
  }

  return isWow64;
}

这是一个基于微软http://1code.codeplex.com/SourceControl/changeset/view/39074#842775代码的解决方案。它使用扩展方法方便代码重用。

下面是一些可能的用法:

bool bIs64BitOS = System.Environment.OSVersion.IsWin64BitOS();

bool bIs64BitProc = System.Diagnostics.Process.GetCurrentProcess().Is64BitProc();

//Hosts the extension methods  
public static class OSHelperTools  
{  
    /// <summary>     
    /// The function determines whether the current operating system is a      
    /// 64-bit operating system.     
    /// </summary>     
    /// <returns>     
    /// The function returns true if the operating system is 64-bit;      
    /// otherwise, it returns false.     
    /// </returns>    
    public static bool IsWin64BitOS(this OperatingSystem os)  
    {  
        if (IntPtr.Size == 8)  
        // 64-bit programs run only on Win64           
            return true;   
        else// 32-bit programs run on both 32-bit and 64-bit Windows     
        {   // Detect whether the current process is a 32-bit process                
            // running on a 64-bit system.               
            return Process.GetCurrentProcess().Is64BitProc();  
        }  
    }  

    /// <summary>  
    /// Checks if the process is 64 bit  
    /// </summary>  
    /// <param name="os"></param>  
    /// <returns>  
    /// The function returns true if the process is 64-bit;        
    /// otherwise, it returns false.  
    /// </returns>    
    public static bool Is64BitProc(this System.Diagnostics.Process p)  
    {  
        // 32-bit programs run on both 32-bit and 64-bit Windows           
        // Detect whether the current process is a 32-bit process                
        // running on a 64-bit system.               
        bool result;  
        return ((DoesWin32MethodExist("kernel32.dll", "IsWow64Process") && IsWow64Process(p.Handle, out result)) && result);  
    }  

    /// <summary>     
    /// The function determins whether a method exists in the export      
    /// table of a certain module.     
    /// </summary>     
    /// <param name="moduleName">The name of the module</param>     
    /// <param name="methodName">The name of the method</param>     
    /// <returns>     
    /// The function returns true if the method specified by methodName      
    /// exists in the export table of the module specified by moduleName.     
    /// </returns>       
    static bool DoesWin32MethodExist(string moduleName, string methodName)  
    {  
        IntPtr moduleHandle = GetModuleHandle(moduleName);  
        if (moduleHandle == IntPtr.Zero)  
            return false;    
        return (GetProcAddress(moduleHandle, methodName) != IntPtr.Zero);   
    }  
    [DllImport("kernel32.dll")]  
    static extern IntPtr GetCurrentProcess();  

    [DllImport("kernel32.dll", CharSet = CharSet.Auto)]  
    static extern IntPtr GetModuleHandle(string moduleName);  

    [DllImport("kernel32", CharSet = CharSet.Auto, SetLastError = true)]  
    static extern IntPtr GetProcAddress(IntPtr hModule, [MarshalAs(UnmanagedType.LPStr)]string procName);  

    [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]  
    [return: MarshalAs(UnmanagedType.Bool)]  
    static extern bool IsWow64Process(IntPtr hProcess, out bool wow64Process);  
}

下面是Windows管理规范(WMI)方法:

string _osVersion = "";
string _osServicePack = "";
string _osArchitecture = "";

ManagementObjectSearcher searcher = new ManagementObjectSearcher("select * from Win32_OperatingSystem");
ManagementObjectCollection collection = searcher.Get();

foreach (ManagementObject mbo in collection)
{
    _osVersion = mbo.GetPropertyValue("Caption").ToString();
    _osServicePack = string.Format("{0}.{1}", mbo.GetPropertyValue("ServicePackMajorVersion").ToString(), mbo.GetPropertyValue("ServicePackMinorVersion").ToString());

    try
    {
        _osArchitecture = mbo.GetPropertyValue("OSArchitecture").ToString();
    }
    catch
    {
        // OSArchitecture only supported on Windows 7/Windows Server 2008
    }
}

Console.WriteLine("osVersion     : " + _osVersion);
Console.WriteLine("osServicePack : " + _osServicePack);
Console.WriteLine("osArchitecture: " + _osArchitecture);

/////////////////////////////////////////
// Test on Windows 7 64-bit
//
// osVersion     : Microsoft Windows 7 Professional
// osservicePack : 1.0
// osArchitecture: 64-bit

/////////////////////////////////////////
// Test on Windows Server 2008 64-bit
//    --The extra r's come from the registered trademark
//
// osVersion     : Microsoftr Windows Serverr 2008 Standard
// osServicePack : 1.0
// osArchitecture: 64-bit

/////////////////////////////////////////
// Test on Windows Server 2003 32-bit
//    --OSArchitecture property not supported on W2K3
//
// osVersion     : Microsoft(R) Windows(R) Server 2003, Standard Edition
// osServicePack : 2.0
// osArchitecture:

我正在使用以下代码。注意:它是为AnyCPU项目制作的。

    public static bool Is32bitProcess(Process proc) {
        if (!IsThis64bitProcess()) return true; // We're in 32-bit mode, so all are 32-bit.

        foreach (ProcessModule module in proc.Modules) {
            try {
                string fname = Path.GetFileName(module.FileName).ToLowerInvariant();
                if (fname.Contains("wow64")) {
                    return true;
                }
            } catch {
                // What on earth is going on here?
            }
        }
        return false;
    }

    public static bool Is64bitProcess(Process proc) {
        return !Is32bitProcess(proc);
    }

    public static bool IsThis64bitProcess() {
        return (IntPtr.Size == 8);
    }

在你的项目中包含以下代码:

    [DllImport("kernel32.dll", SetLastError = true, CallingConvention = CallingConvention.Winapi)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool IsWow64Process([In] IntPtr hProcess, [Out] out bool wow64Process);

    public static int GetBit()
    {
        int MethodResult = "";
        try
        {
            int Architecture = 32;

            if ((Environment.OSVersion.Version.Major == 5 && Environment.OSVersion.Version.Minor >= 1) || Environment.OSVersion.Version.Major >= 6)
            {
                using (Process p = Process.GetCurrentProcess())
                {
                    bool Is64Bit;

                    if (IsWow64Process(p.Handle, out Is64Bit))
                    {
                        if (Is64Bit)
                        {
                            Architecture = 64;

                        }

                    }

                }

            }

            MethodResult = Architecture;

        }
        catch //(Exception ex)
        {
            //ex.HandleException();
        }
        return MethodResult;
    }

像这样使用它:

string Architecture = "This is a " + GetBit() + "bit machine";