vs Dynamic Library Debugging

In the program development, often use to the dynamic library, the dynamic library cannot run directly, needs to depend on other program calls, then how should we debug our dynamic library? This article is illustrated by a simple example.

Use tool: VS2008

Languages used: C + +

Development steps:

1. Invoking the application of the Dynamic Library 1.1 New dialog box application
1.2 Designing a dynamic library interface This interface is used to display some basic information about a dynamic library when loading a dynamic library DllTestAppDlg.h

struct Tdll_information{lpctstrsdllname; LPCTSTRSFUNCDESCR; Lpctstrsauthorname;}; typedef BOOL (*lpfnregister_createobject) (void**); typedef bool (*lpfnregister_getdllinformation) (void**); typedef BOOL (*lpfnregister_releaseobject) (void*);

DllTestAppDlg.cpp

void Cdlltestappdlg::onbnclickedbtnload () {CString S1 = _t (""), s=_t (""); s = _t ("DLL files (*.dll) |*.dll| All Files (*. *) |*.*| |"); CFileDialog de (True, S1, NULL, Ofn_hidereadonly | Ofn_overwriteprompt | Ofn_nochangedir,s, NULL); if (DE. DoModal () = = IDOK) {m_sdllpathname = de. GetPathName ();//path and Filename}else{return;} if (M_sdllpathname.isempty ()) {M_btnrundll.enablewindow (FALSE);} Else{m_btnrundll.enablewindow (TRUE);} CString str = _t (""); int cnt = 0,i = 0;char p[256]={0}; Lpfnregister_getdllinformation Lpfnregister; HInstance Hindll = Null;hindll = LoadLibrary (m_sdllpathname); str = _t ("getdllinformation"); cnt = str. GetLength (); for (i=0; i<cnt; i++) {p[i] = str. GetAt (i);} Lpfnregister= (lpfnregister_getdllinformation) GetProcAddress (hindll,p); tdll_information* pInfo = NULL; (* Lpfnregister) ((void**) &pinfo); str = Pinfo->sdllname;m_sdllname = _t (""); cnt = str. GetLength (); for (i=0;i<cnt;i++) {m_sdllname = M_sdllname + str. GetAt (i);} str = PINFO-&GT;SFUNCDESCR;M_SFUNCDESCR = _t (""); cnt = str. Getlength (); for (i=0;i<cnt;i++) {M_SFUNCDESCR = M_sfuncdescr + str. GetAt (i);} str = Pinfo->sauthorname;m_sauthorname = _t (""); cnt = str. GetLength (); for (i=0;i<cnt;i++) {m_sauthorname = M_sauthorname + str. GetAt (i);} FreeLibrary (Hindll); UpdateData (0);}

Effect 1.3 Design Call Interface class

MyDllService.h

#pragma once#define err_ser_ok             0x0000#define err_ser_run_failed     0x0001#define err_ser_run_cancel     0x0002#define err_ser_load_param     0x0003class cmydllservice{public:cmydllservice (void) {};~CMyDllService (void) {};p ublic:virtual DWORD runservice () {return err_ser_run_failed;};};

Call

void Cdlltestappdlg::onbnclickedbtnrun () {if (M_sdllpathname.isempty ()) {MessageBox (_t ("DLL path is empty. "); return;} cmydllservice* pser = NULL; hinstance hin = Null;hin = LoadLibrary (M_sdllpathname), if (hIn! = invalid_handle_value) {}else{cstring info = _t ("load") + m_s Dllpathname + _t ("failure"); MessageBox (info); return;} CString str = _t (""); int cnt = 0,i = 0;char P[256]={0};str = _t ("createobject"); cnt = str. GetLength (); for (i=0; i<cnt; i++) {p[i] = str. GetAt (i);} Lpfnregister_createobject lpfnregister;lpfnregister= (Lpfnregister_createobject) GetProcAddress (hIn,p); bool Result = False;if (lpfnregister) {result = (*lpfnregister) ((void**) & (Pser));} Else{freelibrary (HIn); CString info = _t ("load") + M_sdllpathname + _t ("failed"); MessageBox (info); return;} if (pser && result) {DWORD dwerror = 0;dwerror = Pser->runservice ();} Else{freelibrary (HIn); CString info = _t ("Run") + M_sdllpathname + _t ("failed"); MessageBox (info); return;} Char p2[256]={0};str = _t ("Releaseobject"); cnt = str. GetLength (); for (i=0; i<cnt; i++) {P2[I] = str. GetAt (i);} Lpfnregister_releaseobject lpfnregister1;lpfnregister1= (Lpfnregister_releaseobject) GetProcAddress (HIN,P2); LpfnRegister1) {result = (*lpfnregister1) ((void*) pser);p ser = NULL;} FreeLibrary (hIn);}

Effect

1.4 File Structure diagram

2. dialog box Dynamic Library

2.1 New dialog box Dynamic Library

Set properties to use in a static library

2.2 Adding an interface class
2.3 Derive your own class from the interface class and re-MyDlgDllService.h the virtual function

#pragma once#include "mydllservice.h" class Cmydlgdllservice:public cmydllservice{public:cmydlgdllservice (void); ~ Cmydlgdllservice (void);D word runservice (void);};

MyDlgDllService.cpp

#include "StdAfx.h" #include "MyDlgDllService.h" #include "TestDlg.h" cmydlgdllservice::cmydlgdllservice (void) {} Cmydlgdllservice::~cmydlgdllservice (void) {}dword cmydlgdllservice::runservice (void) {Ctestdlg dlg;dlg. DoModal (); return ERR_SER_OK;}

2.4 Designing the Dynamic Library interface

struct Tdll_information{lpctstrsdllname; LPCTSTRSFUNCDESCR; Lpctstrsauthorname;}; extern "C" __declspec (dllexport) bool CreateObject (void** POBJ) {*pobj  = new Cmydlgdllservice;return true;} extern "C" __declspec (dllexport) bool Getdllinformation (void** pInfo) {*pinfo = new Tdll_information; ((tdll_information *) (*pinfo))->sdllname = _t ("DLL");((tdll_information*) (*pinfo))->SFUNCDESCR = _t ("DLL test");((Tdll_ information*) (*pinfo))->sauthorname = _t ("tester"); return true;} extern "C" __declspec (dllexport) bool Releaseobject (void* pObj) {cmydlgdllservice* ptempobj = Null;ptempobj = ( cmydlgdllservice*) Pobj;delete Ptempobj;return true;}

2.5 File Structure diagram

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vs Dynamic Library Debugging