DLL encapsulation and invocation of "C + +" multiple classes

 DLL encapsulation and invocation of "C + +" multiple classesCategory: "Programming language"2012-07-11 18:53 6399 people read review (a) collection report dllc++includebuild2010

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Most of the online tutorial is to encapsulate functions as DLLs, and the encapsulation of classes is basically similar.

Creating DLLs

Create a new Win32->dll project in the VS2010. As I set up the project named Facedll

Add facedll.h header file (the interface that defines the DLL, which is used when called)

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2. #pragma once
4. #ifdef Facelibdll
6. #define FACEAPI _declspec (dllexport)
8. #else
10. #define FACEAPI _declspec (dllimport)
12. #endif
14. You can include header files that you need to use
16. #include <opencv2/opencv.hpp>
20. Class Faceapi Facerecognizer
22. {
24. Public
26. Facerecognizer ();
28. ~facerecognizer ();
32. /////////////////////////////////////
34. Functions of the class
38. };

The function implementation is then written in Facedll.cpp and is defined as Facelibdll

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1. #define  FaceLIBDLL  
2.   
3. #include   "stdafx.h"    
4. #include   "facedll.h" &NBSP;&NBSP;
5. #include  <opencv2/opencv.hpp>  
6.   
7. //////////the implementation of functions in the header file   
8. Facerecognizer::facerecognizer ()    
9. {&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;
10.   
11. }   
12.   
13. facerecognizer::~facerecognizer ()    
14. {      
15. &NBSP;&NBSP;
16. }   

Build project, the corresponding DLL and LIB files will be generated in the Debug folder: Facedll.dll facedll.lib

Multiple classes encapsulate DLLs

After encapsulating a class, the following class can invoke the DLL generated by the class, and then encapsulate the DLL for the new class.

You need to add header files, such as facedll.h, that need to be referenced in your project. Copy the Facedll.lib file in Debug. In properties->linker->input-> Additional dependecies add facedll.lib (or write full path: "... \debug\facedll.lib ")

And then the same way to encapsulate the new class is the ~

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2. #pragma once
4. #ifdef Heartlibdll
6. #define HEARTAPI _declspec (dllexport)
8. #else
10. #define HEARTAPI _declspec (dllimport)
12. #endif
16. #include <opencv2/opencv.hpp>
18. #include "facedll.h"
20. #include "datadll.h"
24. Class Heartapi Hrmeasure
26. {
28. }；

Calling DLL calls requires the. h,. dll,. lib files for each DLL. Add a header file to your project and include it where you need it. The Lib file is copied to the project and written in Properties->linker->input-> Additional dependecies: Facedll.lib;heartdll.lib. or write in the program: [CPP]View Plaincopy

1. #pragma comment (lib, "Facedll.lib")
2. #pragma comment (lib, "Heartdll.lib")

Classes that are encapsulated into DLLs can then be used directly in the program: [CPP]View Plaincopy

1. Hrmeasure *hrmea=New Hrmeasure ();

DLL encapsulation and invocation of "C + +" multiple classes