的Python ctypes的整数指针

Question

我如何使用python的ctypes

extern int __stdcall GetRate(HANDLE hDev, int* pData) 

如何设置数据类型，这样我可以打印的pData值

Answer 1

如果要调用一个函数命名GetRate实现这个功能，你可以做到这一点的：

from ctypes import * 
from ctypes.wintypes import * 

GetRate = windll.YOURLIB.GetRate 
GetRate.restype = c_int 
GetRate.argtypes = [HANDLE, POINTER(c_int)] 

# now call GetRate as something like: 
# 
# hDev = ... # handle 
# Data = c_int() 
# 
# GetRate(hDev, byref(Data)) # GetRate(hDev, &Data) 
# print Data 

，但如果你试图声明回调，函数指针，你可以做到这一点的（我认为你在寻找在前）：

from ctypes import * 
from ctypes.wintypes import * 

def GetRate(hDev, pDate): 
    # Your implementation 
    return 0 

# you'll need GETRATE to pass it in the argtypes to the target function 
GETRATE = WINFUNCTYPE(c_int, HANDLE, POINTER(c_int)) 
pGetRate = GETRATE(GetRate) 

# now you can pass pGetRate as a callback to another function