调用 SetupDiGetClassDevsW 函数如何输入参数

Question

我正在使用Python中的SetupDiGetClassDevsW函数，但我不知道如何输入参数 Flags = DIGCF_PRESENT会发生错误NameError: name 'DIGCF_PRESENT' is not defined 请问我该怎么办？

https://docs.microsoft.com/zh-tw/windows/win32/api/setupapi/nf-setupapi-setupdigetclassdevsw?redirectedfrom=MSDN

import ctypes as ct
from ctypes import wintypes as w

SetupAPI = ct.WinDLL('SetupAPI')

SetupAPI.SetupDiGetClassDevsW.argtypes = w.CHAR,w.PWCHAR,w.HWND,w.DWORD
SetupAPI.SetupDiGetClassDevsW.restype = w.HANDLE

ClassGuid = None
Enumerator = None
hwndParent = None
Flags = DIGCF_PRESENT

Handle = SetupAPI.SetupDiGetClassDevsW(ClassGuid,
                                       Enumerator,
                                       hwndParent,
                                       Flags)

更新 - 2

更新后的代码如下，打印HANDLE得到18446744073709551615对吗？预计获取设备信息。

import ctypes as ct
from ctypes import wintypes as w

SetupAPI = ct.WinDLL('SetupAPI')

SetupAPI.SetupDiGetClassDevsW.argtypes w.LPVOID,w.PWCHAR,w.HWND,w.DWORD
SetupAPI.SetupDiGetClassDevsW.restype = w.HANDLE

DIGCF_DEFAULT         =  0x00000001  
DIGCF_PRESENT         =  0x00000002
DIGCF_ALLCLASSES      =  0x00000004
DIGCF_PROFILE         =  0x00000008
DIGCF_DEVICEINTERFACE =  0x00000010

ClassGuid = None
Enumerator = None
hwndParent = None
Flags = DIGCF_PRESENT

Handle = SetupAPI.SetupDiGetClassDevsW(ClassGuid,
                                       Enumerator,
                                       hwndParent,
                                       Flags)
print(Handle)

Answer 1

在SetupApi.h中查找：

//
// Flags controlling what is included in the device information set built
// by SetupDiGetClassDevs
//
#define DIGCF_DEFAULT           0x00000001  // only valid with DIGCF_DEVICEINTERFACE
#define DIGCF_PRESENT           0x00000002
#define DIGCF_ALLCLASSES        0x00000004
#define DIGCF_PROFILE           0x00000008
#define DIGCF_DEVICEINTERFACE   0x00000010

然后可以在Python中定义常量:

DIGCF_DEFAULT         =  0x00000001  # only valid with DIGCF_DEVICEINTERFACE
DIGCF_PRESENT         =  0x00000002
DIGCF_ALLCLASSES      =  0x00000004
DIGCF_PROFILE         =  0x00000008
DIGCF_DEVICEINTERFACE =  0x00000010

还要注意 SetupDiGetClassDevsW 的第一个参数是 GUID*，而不是 CHAR，所以 .argtypes 应该至少是 w.LPVOID 如果你只是通过了 None.

也看看examples in the documentation。 returns 下方的有效句柄：

import ctypes as ct
from ctypes import wintypes as w

SetupAPI = ct.WinDLL('SetupAPI')

SetupAPI.SetupDiGetClassDevsW.argtypes = w.LPVOID,w.PWCHAR,w.HWND,w.DWORD
SetupAPI.SetupDiGetClassDevsW.restype = w.HANDLE

DIGCF_DEFAULT         =  0x00000001  
DIGCF_PRESENT         =  0x00000002
DIGCF_ALLCLASSES      =  0x00000004
DIGCF_PROFILE         =  0x00000008
DIGCF_DEVICEINTERFACE =  0x00000010

ClassGuid = None
Enumerator = None
hwndParent = None
Flags = DIGCF_PRESENT | DIGCF_ALLCLASSES

Handle = SetupAPI.SetupDiGetClassDevsW(ClassGuid,
                                       Enumerator,
                                       hwndParent,
                                       Flags)
print(hex(Handle))

输出：

0x1e4258bcb50

调用 SetupDiGetClassDevsW 函数如何输入参数

Calling SetupDiGetClassDevsW function How to enter parameters

python

ctypes

调用 SetupDiGetClassDevsW 函数 如何输入参数

Calling SetupDiGetClassDevsW function How to enter parameters

python

ctypes

调用 SetupDiGetClassDevsW 函数如何输入参数