如何使用ctypes将SendInput函数包装到python

Question

我试图从user32.dll获取SendInput函数，以便使用ctypes在python中工作。我是一个noob，但从我从文档中读取的内容来看，您必须在python中创建函数所需的结构，然后将其传递给函数

import ctypes
import keyboard
from ctypes import *
lib = windll.user32

KEYEVENTF_SCANCODE = 0x8
KEYEVENTF_KEYUP = 0x2
SPACEBAR = 57 # 0x39
INPUT_KEYBOARD = 1


class KEYBDINPUT(Structure):
    _fields_ = [('wVk' , c_ushort) , ('wScan' , c_ushort)
    , ('dwFlags' , c_ulong) , ('time' , c_ulong) , ('dwExtraInfo' , c_ulong)]
class INPUT(Structure):
    _fields_ = [('type' , c_ulong) ,('ki' , KEYBDINPUT)]


lib.SendInput.restype = c_uint
lib.SendInput.argtypes = [c_uint , INPUT , c_int]

keybdinput_obj = KEYBDINPUT(0 , SPACEBAR , KEYEVENTF_SCANCODE , 0 , 0)
input_obj = INPUT(INPUT_KEYBOARD , keybdinput_obj)
keyboard.wait('u')
lib.SendInput(1 , byref(input_obj) , sizeof(INPUT))
keybdinput_obj = KEYBDINPUT(0 , SPACEBAR , KEYEVENTF_SCANCODE | KEYEVENTF_KEYUP , 0 , 0)
input_obj = INPUT(INPUT_KEYBOARD , keybdinput_obj)
lib.SendInput(1 , byref(input_obj) , sizeof(INPUT))

在我从输入结构引导自己的microsoft文档中，有一个union，但我想如果我只需要KEYBDINPUT，那么它与我有一个union是一样的

https://docs.microsoft.com/en-us/windows/win32/api/winuser/ns-winuser-input

https://docs.microsoft.com/en-us/windows/win32/api/winuser/ns-winuser-keybdinput

https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-sendinput

我几乎被卡住了，因为我看不出这里出了什么问题，所以我请求帮助。程序应该在我按下键盘上的“u”后发送一个空格（这是为了调试），我这样做是因为我希望它以扫描码而不是虚拟按键的形式发送

因此，如果python中有另一种方法可以用来发送扫描代码，那就行了，我将非常感谢

Answer 1

定义整个联合体，或者至少定义鼠标输入，它是联合体的最大成员。您可以通过打印测试定义的大小是否正确（sizeof（INPUT）），并且它应该与在C程序中打印输入结构的大小一致。对于32位C结构，我得到了28码，对于64位C结构，得到了40码

另外，SendInput的第二个参数是指针（INPUT），而不是INPUT，而ULONG_PTR不一定是c_ulong，因为它依赖于运行32位或64位Python

下面是一个经过测试的示例：

import ctypes
from ctypes import *
from ctypes import wintypes as w

KEYEVENTF_SCANCODE = 0x8
KEYEVENTF_UNICODE = 0x4
KEYEVENTF_KEYUP = 0x2
SPACE = 0x39
INPUT_KEYBOARD = 1

# not defined by wintypes
ULONG_PTR = c_ulong if sizeof(c_void_p) == 4 else c_ulonglong

class KEYBDINPUT(Structure):
    _fields_ = [('wVk' ,w.WORD),
                ('wScan',w.WORD),
                ('dwFlags',w.DWORD),
                ('time',w.DWORD),
                ('dwExtraInfo',ULONG_PTR)]

class MOUSEINPUT(Structure):
    _fields_ = [('dx' ,w.LONG),
                ('dy',w.LONG),
                ('mouseData',w.DWORD),
                ('dwFlags',w.DWORD),
                ('time',w.DWORD),
                ('dwExtraInfo',ULONG_PTR)]

class HARDWAREINPUT(Structure):
    _fields_ = [('uMsg' ,w.DWORD),
                ('wParamL',w.WORD),
                ('wParamH',w.WORD)]

class DUMMYUNIONNAME(Union):
    _fields_ = [('mi',MOUSEINPUT),
                ('ki',KEYBDINPUT),
                ('hi',HARDWAREINPUT)] 

class INPUT(Structure):
    _anonymous_ = ['u']
    _fields_ = [('type',w.DWORD),
                ('u',DUMMYUNIONNAME)]

print(sizeof(INPUT))

lib = WinDLL('user32')
lib.SendInput.argtypes = w.UINT,POINTER(INPUT),c_int
lib.SendInput.restype = w.UINT

def send_scancode(code):
    i = INPUT()
    i.type = INPUT_KEYBOARD
    i.ki = KEYBDINPUT(0,code,KEYEVENTF_SCANCODE,0,0)
    lib.SendInput(1,byref(i),sizeof(INPUT))
    i.ki.dwFlags |= KEYEVENTF_KEYUP
    lib.SendInput(1,byref(i),sizeof(INPUT))

def send_unicode(s):
    i = INPUT()
    i.type = INPUT_KEYBOARD
    for c in s:
        i.ki = KEYBDINPUT(0,ord(c),KEYEVENTF_UNICODE,0,0)
        lib.SendInput(1,byref(i),sizeof(INPUT))
        i.ki.dwFlags |= KEYEVENTF_KEYUP
        lib.SendInput(1,byref(i),sizeof(INPUT))

send_scancode(SPACE)
send_unicode('The quick brown fox jumped over the lazy dog')

运行64位Python 3.6的终端上的输出：

C:\>example
40

C:\> The quick brown fox jumped over the lazy dog