如何使用 cpython 将结构数组传递给 DLL 函数？

Question

#include <stdio.h>

struct struct_data {

    int price;

    char list[255];

    int count;

};

__declspec(dllexport) void __stdcall testcall(struct struct_data *array_data) {

    int i = 0;

    while(array_data[i].price != 0) {           // array_data is guaranteed to have a zero somewhere inside memory allocated for the array

        printf("%d\n", array_data[i].price);

        i++;

    }

}

我尝试使用 cpython 从 Python 调用它，如下所示：

# C Backend imports

import os

import sys

import ctypes

# load DLL

dll = ctypes.WinDLL('C:\\Users\\user\Documents\\Pelles C Projects\\MarketlibDLL\\MarketlibDLL.dll')

class struct_data(ctypes.Structure):

    _fields_ = [

        ('price', ctypes.c_int),

        ('list', ctypes.c_char * 255),

        ('count', ctypes.c_int),

    ]

d = struct_data() * 100    # I try to do:   struct struct_data d[100]; 

d[0].price = 100

d[0].list = "ABC"

d[0].count = 3

d[1].price = 0

dll.testcall.argtypes = [ctypes.POINTER(struct_data)]

dll.testcall(d)

---------------------------------------------------------------------------

TypeError                                 Traceback (most recent call last)

<ipython-input-2-36161e840b5f> in <module>

----> 1 d = struct_data() * 100

      2 d[0].price = 100

      3 d[0].list = "ABC"

      4 d[0].count = 3

      5 d[1].price = 0

TypeError: unsupported operand type(s) for *: 'struct_data' and 'int'

Answer 1

[Python 3.Docs]：ctypes - Python 的外部函数库具有所有必需的信息（数组部分包含一个完美映射当前场景的示例）。将您的代码修改为（为了便于阅读，分成两行）：struct_data_array_100 = struct_data * 100&nbsp; # !!! This is a type (array consisting of 100 struct_data elements) !!!d = struct_data_array_100()&nbsp; # Instantiate the array type#d[0].price ...# ...

Answer 2

如果你想要一个 100 的列表，struct_data你需要将列表而不是数据相乘：d&nbsp;=&nbsp;[struct_data()]&nbsp;*&nbsp;100这和写法一样：d&nbsp;=&nbsp;[struct_data()&nbsp;for&nbsp;_&nbsp;in&nbsp;range(100)]