python 使用ctypes调用C/C++ dll详情

extern "C"{

struct MyStruct{
int num_int;
long num_long;
float num_float;
double num_double;
char* num_str;
};

int __declspec(dllexport) print(MyStruct my)
printf("%d\n", my.num_int);
printf("%d\n", my.num_long);
printf("%f\n", my.num_float);
printf("%f\n", my.num_double);
printf("%s\n", my.num_str);
}

import ctypes

class MyStruct(Structure):
_fields_ = [
("num_int", c_int),
("num_long", c_long),
("num_float", c_float),
("num_double", c_double),
("num_str", c_char_p)
]

# dll全路径，依赖完整
dll = ctypes.WinDLL("C:\\work\\mytest.dll")

#调用
my = MyStruct();
my.num_int = 23
my.num_long = 1024
my.num_float = 3.14
my.num_double = 3.141592653
my.num_str = b"hello world"
dll.print(my)

<strong>#pragma pack(4)</strong>
struct MyStruct{
int num_int;
long num_long;
float num_float;
double num_double;
char* num_str;
};

class MyStruct(Structure):
<strong>_pack_ </strong><strong>= 4</strong>
_fields_ = [
("num_int", c_int),
("num_long", c_long),
("num_float", c_float),
("num_double", c_double),
("num_str", c_char_p)
]