获取Window是32位还是64位系统

Windows常用的两个获取系统信息的API：

void WINAPI GetNativeSystemInfo(    _Out_ LPSYSTEM_INFO lpSystemInfo);void WINAPI GetSystemInfo(  _Out_ LPSYSTEM_INFO lpSystemInfo);lpSystemInfo ：指向一个供函数返回信息的SYSTEM_INFO结构体。SYSTEM_INFO结构体定义如下：typedef struct _SYSTEM_INFO{    union    {        DWORD dwOemId;        struct {            WORD wProcessorArchitecture;            WORD wReserved;        };    };    DWORD dwPageSize;    LPVOID lpMinimumApplicationAddress;    LPVOID lpMaximumApplicationAddress;    DWORD_PTR dwActiveProcessorMask;    DWORD dwNumberOfProcessors;    DWORD dwProcessorType;    DWORD dwAllocationGranularity;    WORD wProcessorLevel;    WORD wProcessorRevision;} SYSTEM_INFO;[1] SYSTEM_INFO结构体参数说明：wProcessorArchitecture: Word;　{处理器的体系结构}wReserved: Word;　 {保留}dwPageSize: DWORD;　 {分页大小}lpMinimumApplicationAddress: Pointer;{最小寻址空间}lpMaximumApplicationAddress: Pointer;{最大寻址空间}dwActiveProcessorMask: DWORD;　{处理器掩码; 0..31 表示不同的处理器}dwNumberOfProcessors: DWORD;　 {处理器数目}dwProcessorType: DWORD;　{处理器类型}dwAllocationGranularity: DWORD;　{虚拟内存空间的粒度}wProcessorLevel: Word;　 {处理器等级}wProcessorRevision: Word);　 {处理器版本}

注意：GetSystemInfo支持的最低客户端/服务器
Minimum supported client
Windows 2000 Professional [desktop apps | Windows Store apps]
Minimum supported server
Windows 2000 Server [desktop apps | Windows Store apps]
GetNativeSystemInfo支持的最低客户端/服务器
Minimum supported client
Windows XP [desktop apps | Windows Store apps]
Minimum supported server
Windows Server 2003 [desktop apps | Windows Store apps]
因此在使用的过程中我们要注意平台的处理。

typedef void (WINAPI *LPFN_PGNSI)(LPSYSTEM_INFO); int Is64BitSystem(){    SYSTEM_INFO si;    int    is64bit  = 0;    HINSTANCE handle;    LPFN_PGNSI  func;    SYSTEM_INFO * sip;    handle = LoadLibraryA("kernel32.dll");    if (handle)    {        func = (LPFN_PGNSI ) GetProcAddress(handle,"GetNativeSystemInfo");        if (func)        {            func(&si);        }        else        {            GetSystemInfo(&si);        }        FreeLibrary(handle);    }    else    {        GetSystemInfo(&si);    }    if (si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_AMD64 ||             si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_IA64 )     {             //64 位操作系统             is64bit = 1;    }     else     {             // 32 位操作系统             is64bit = 0;    }    return is64bit ;}