python如何调用C++外部库中的类？

Posted 2023-03-26

如外部库
#include "FlyCapture2.h"
using namespace FlyCapture2;
using namespace std;
Camera *pCam；

我怎样在python中用pCam

你好流程比较复杂，需要通过一个c的接口来做。下面是一个简单的例子，你也可以到booth去看看他们是怎么用的。
//YourFile.cpp (compiled into a .dll or .so file)
#include
//For std::nothrow
//Either include a header defining your class, or define it here.
extern "C" //Tells the compile to use C-linkage for the next scope.

//Note: The interface this linkage region needs to use C only.
void * CreateInstanceOfClass( void )

// Note: Inside the function body, I can use C++.
return new(std::nothrow) MyClass;

//Thanks Chris.
void DeleteInstanceOfClass (void *ptr)

delete(std::nothrow) ptr;

int CallMemberTest(void *ptr)

// Note: A downside here is the lack of type safety.
// You could always internally(in the C++ library) save a reference to all
// pointers created of type MyClass and verify it is an element in that
//structure.
//
// Per comments with Andre, we should avoid throwing exceptions.
try

MyClass * ref = reinterpret_cast
(ptr);
return ref->Test();

catch(...)

return -1; //assuming -1 is an error condition.


//End C linkage scope.

第二步：
gcc -shared -o test.so test.cpp
#creates test.so in your current working directory.
第三步：
>>> from ctypes import cdll
>>> stdc=cdll.LoadLibrary("libc.so.6") # or similar to load c library
>>> stdcpp=cdll.LoadLibrary("libstdc++.so.6") # or similar to load c++ library
>>> myLib=cdll.LoadLibrary("/path/to/test.so")
>>> spam = myLib.CreateInstanceOfClass()
>>> spam
[outputs the pointer address of the element]
>>> value=CallMemberTest(spam)
[does whatever Test does to the spam reference of the object] 参考技术A 你好流程比较复杂，需要通过一个c的接口来做。下面是一个简单的例子，你也可以到booth去看看他们是怎么用的。
//YourFile.cpp (compiled into a .dll or .so file)
#include
//For std::nothrow
//Either include a header defining your class, or define it here.
extern "C" //Tells the compile to use C-linkage for the next scope.

//Note: The interface this linkage region needs to use C only.
void * CreateInstanceOfClass( void )

// Note: Inside the function body, I can use C++.
return new(std::nothrow) MyClass;

//Thanks Chris.
void DeleteInstanceOfClass (void *ptr)

delete(std::nothrow) ptr;

int CallMemberTest(void *ptr)

// Note: A downside here is the lack of type safety.
// You could always internally(in the C++ library) save a reference to all
// pointers created of type MyClass and verify it is an element in that
//structure.
//
// Per comments with Andre, we should avoid throwing exceptions.
try

MyClass * ref = reinterpret_cast
(ptr);
return ref->Test();

catch(...)

return -1; //assuming -1 is an error condition.


//End C linkage scope.

第二步：
gcc -shared -o test.so test.cpp
#creates test.so in your current working directory.
第三步：
>>> from ctypes import cdll
>>> stdc=cdll.LoadLibrary("libc.so.6") # or similar to load c library
>>> stdcpp=cdll.LoadLibrary("libstdc++.so.6") # or similar to load c++ library
>>> myLib=cdll.LoadLibrary("/path/to/test.so")
>>> spam = myLib.CreateInstanceOfClass()
>>> spam
[outputs the pointer address of the element]
>>> value=CallMemberTest(spam)
[does whatever Test does to the spam reference of the object]本回答被提问者和网友采纳