I have created an *.exe and *.dll for my project.
I have provided all the correct path and data.
Myexe.cpp:
#include "stdafx.h"
#include <Windows.h>
int _tmain(int argc, _TCHAR* argv[])
{
HMODULE hInstLibrary = LoadLibrary(L("..\\Debug\\LoadDLL\\LoadDLL.dll"));// I have checked with complete path as well.
if(hInstLibrary)
{
printf("Hello World");
}
return 0;
}
MyDLL.cpp:
#include "MyDLL.h"
#include <stdio.h>
MyDLL::MyDLL(void)
{
}
MyDLL::~MyDLL(void)
{
}
extern "C" __declspec(dllexport) void HelloWorld()
{
printf("Hello DLL");
}
MyDLL.h:
#pragma once
class __declspec(dllexport) MyDLL
{
public:
MyDLL(void);
~MyDLL(void);
};
extern "C" __declspec(dllexport) void HelloWorld();
I have tried providing the complete path also. But it is still failing. The hInstLibrary is setting to 0x00000. I tried in Release mode too but the problem still lies there.
But when I have tried with:
HMODULE hInstLibrary = LoadLibrary(_T("C:\\Windows\\System32\\aeinv.dll"));
it does load the DLL. So, please help me where is it going wrong. The DLL gets build properly, there is absolutely no error in building DLL. Then why am I facing this problem??
Is there any setting need to be done for Debug.
You need to call GetLastError to find out what went wrong.
Edit:
You got 0x7e, which means:
ERROR_MOD_NOT_FOUND
126 (0x7E)
The specified module could not be found.
Your path is wrong. You need to fix that.
Inspect your executable with DependencyWalker and the profile it from there. You'll get a better picture as to why your dll fails to load and how the dependency tree looks like.
When you start profiling (F7) make sure that 'Log LoadLibrary function calls' is checked.
You can also check Dynamic-Link Library Search Order to see if anything is applicable to your specific case.
What's L in L("..\\Debug\\LoadDLL\\LoadDLL.dll")? You probably meant L"..\\Debug\\LoadDLL\\LoadDLL.dll" without the parentheses for a wide-char string. I'm not sure how that compiles unless you created an L macro? The _T(x) macro expands to L ## x (in wide-char builds), by the way...
Related
Here is the error I am receiving when running the project that I am using the DLL in:
The odd thing is that this was working at one point. I took a break from this project for a while and now it is not working. Not much has changed besides changing a couple of the parameters.
My setup includes a project in which I build the DLL. This project is then used in a solution with another project that I use to test it. I followed this example: https://msdn.microsoft.com/en-us/library/ms235636.aspx in which I also followed the first time and had it working, now it has stopped.
After realizing it seems to be only one of the functions that is causing the problem I have removed all of the extra code, tried renaming the function, removing everything in it and it is STILL not working.
You can see the function definitions and signatures to see how I am attempting to get this to work below
I have also tried using the "SCOREINTERFACECPP" macro I created on the function instead of the class and I get the same error.
In the project I am testing it in I added the DLL project as a reference and a dependent project, then imported the header file. The other functions I have in the dll (that I have removed from this code for simplicity sake) seem to be working.
Header:
#ifdef SCOREINTERFACECPP_EXPORTS
#define SCOREINTERFACECPP __declspec(dllexport)
#else
#define SCOREINTERFACECPP __declspec(dllimport)
#endif
#include <time.h>
#include <queue>
namespace ScoreInterfaceCPP
{
class SCOREINTERFACECPP ScoreInterface
{
public:
ScoreInterface();
~ScoreInterface();
static void SubmitLogin(const std::string &displayName, const std::string &password);
static void Shutdown();
static SIEvent* GetNextEvent();
static void ClearEvents();
static int GetEventCount();
private:
static std::queue< SIEvent* > mSIEvents;
static bool mGameIsAuthorized;
static std::string mGameName;
static std::string hexedKey;
static std::wstring mAddress;
static void SubmitEventString(std::string eventString);
static int SubmitWithNewThread(void* data);
static void PostMessage(std::string data, std::string iv);
};
}
Source:
#include <sstream>
#include <SDL/SDL_thread.h>
#include <boost/tokenizer.hpp>
#include "ScoreInterfaceCPP.h"
#include "Network.h"
using namespace ScoreInterfaceCPP;
/*
ScoreInterfaceCPP.h
Handles the sending and receiving of events.
*/
ScoreInterface::ScoreInterface()
{
}
ScoreInterface::~ScoreInterface()
{
}
void ScoreInterface::SubmitLogin(const std::string &displayName, const std::string &password)
{
}
void ScoreInterface::SubmitEventString(std::string eventString)
{
}
int ScoreInterface::SubmitWithNewThread(void* data)
{
return 0;
}
SIEvent* ScoreInterface::GetNextEvent()
{
return NULL;
}
int ScoreInterface::GetEventCount()
{
return 0;
}
void ScoreInterface::ClearEvents()
{
}
void ScoreInterface::Shutdown()
{
}
Test file:
#include "ScoreInterfaceCPP.h"
using namespace ScoreInterfaceCPP;
using namespace std;
int _tmain(int argc, _TCHAR* argv[])
{
ScoreInterface si = ScoreInterface();
si.SubmitLogin("noplayer", "nopassword");
return 0;
}
In my experience, usually problems of this type come with two things you should check (assuming the DLL was built successfully):
Check that the DLL being loaded at runtime is the correct version.
Ensure that the function in question is actually exported.
For the first issue, you can use a utility such as Process Explorer and look at the DLL handles that are loaded for your running exectuable. If you are using Visual C++, you can also look at the Output Window listing of the DLL's that are loaded, and ensure that the version you're using is being loaded.
Many times during development, you may have several (either by accident or by design) versions of your DLL lying in a directory that is accessible by Windows (see DLL Search Order), and thus an old or different version of your DLL is being loaded when you run your application.
For the second issue, there is dumpbin.exe, but I find the Dependency Walker a little more friendly to use. These utilities will show you the functions that are exported from the DLL.
If it is discovered that the function was not exported, then you need to rebuild your DLL, ensuring that __declspec(dllexport) has been used on the function or class you're exporting.
I've got a little problem. I got a dll C library, a header file, and all other files needed to call this dll. I've tried calling this dll through third party programs and it is working.
However, when I try calling it directly (dynamic linking at load and using the given header file) I always get the linker error 1136 with mydll.lib.
Using the header file:
#include "windows.h"
#include "mydll.h"
void main() {
bool test;
test = CallDll("MyArg");
}
With code in headerfile as below:
extern "C" bool _stdcall CallDll(char* MyArg);
Using dynamic linking at load time:
#include "windows.h"
bool(*CallDll)(char*);
HINSTANCE h = LoadLibrary((LPCSTR)"mydll");
void main() {
CallDll = (bool(*)(char*))GetProcAddress(h, "CallDll");
bool test;
test = CallDll("MyArg");
}
Now what did I do wrong? I doubt the mydll.lib file is broken, because if this were the issue, I couldn't access the dll with a third party program.
Well it was a rather simple solution.
bool(*CallDll)(char*);
HINSTANCE h = LoadLibrary(L"mydll.dll");
void main() {
CallDll = (bool(*)(char*))GetProcAddress(h, "CallDll");
bool test;
test = CallDll((char*)"MyArg");
}
Was all it needed...
I have a DLL with the /clr option ON. I have the following declaration in my DLL:
int __declspec(dllexport) __cdecl test();
Also, I have a console with /clr option ON. And have the following declaration on my main.cpp file:
int __declspec(dllimport) __cdecl test();
I added the Reference to the DLL project on the property settings of my console application. But I still get unresolved externals from the compiler about the test function.
I managed to compile by manually adding a reference to the lib file generated by the compiler. But then I can't hit breakpoints inside the DLL functions (it says the source code is different from the original version or the symbols have not been loaded...)
Can someone help me?
If your DLL doesn't use any managed functionality, simply remove the /clr option from that project and recompile. If you still get the errors, it's probably related to the references in the console application.
If the DLL use managed functionality, what you need is instead like so:
DLL:
#include "stdafx.h"
namespace Test1
{
public ref class Test2
{
public:
static int test()
{
return 1;
}
};
}
Console app:
#include <iostream>
int main(int argc, char* argv[])
{
int i = Test1::Test2::test();
std::cout << i << std::endl;
return 0;
}
I use eclipse and mingw compilier (c++).
I would like to create a dll file which contains a lot of strings.
After that I would like to call with LoadString() to read the string (http://msdn.microsoft.com/en-us/library/windows/desktop/ms647486(v=vs.85).aspx)
my dll file:
#define WIN32_LEAN_AND_MEAN
#define DLL_FUNC extern "C" __declspec(dllexport)
DLL_FUNC int __stdcall Hello() {
return 0;
}
my cpp file:
#include <windows.h>
#include <stdio.h>
int main () {
typedef int (__stdcall *HelloProc)();
HMODULE hdll = LoadLibrary("HelloWorld.dll");
if( hdll == NULL){
MessageBox(HWND_DESKTOP, "Wrong dll path", "Message", MB_OK);
}
else {
typedef int (__stdcall *HelloProc)();
HelloProc Hello = (HelloProc)GetProcAddress(hdll, "Hello#0");
if(Hello == NULL){
//LoadString();
MessageBox(HWND_DESKTOP, "Hello is NULL", "Message", MB_OK);
}
else{
Hello();
}
}
return 0;
}
How do I create the strings? And how to call with LoadString()?
I think you want to read about resources so that you can build a resource-only DLL containing a string table. Try searching the MSDN site you referenced for things like resource compiler and maybe how to build a resource only DLL and how to use string tables. I'm sure you will find documentation and examples at Microsoft and, if not, with Google.
Oh, your DLL is not required to be resource only, I got that from your comment "I would like to create a dll file which contains a lot of strings." It is actually even easier (maybe more straightforward) to do if your DLL will also contain code. Then you'd want to search for adding resources to a DLL and things like that.
I am trying to import a dll to a C# console application just to see if I can get a dll to work as a want, when trying this and exporting functions with C-code everything works fine and the functions can be imported in my C# application.
The problem starts when I try to add some kind of linkage to some QT methods in my unmanaged dll. I'm using DllImport to import the functions from the dll.
[DllImport("cDLL.dll", EntryPoint = "_Add#16")]
static extern double Add(double a, double b);
1 - This is how the unmanaged dll (don't look at the functionality of the code, this is just for testing purposes) looks like when it works fine.
main.cpp working
#include <stdexcept>
#include "Windows.h"
using namespace std;
extern "C" __declspec(dllexport) double __stdcall Add(double a, double b)
{
return a + b;
}
extern "C" __declspec(dllexport) const char* getText()
{
return "hello world";//returnBufferString.c_str();
}
BOOL __stdcall DllMain(HINSTANCE hInst, DWORD dwReason, LPVOID lpReserved) {
return TRUE;
}
2 - When I try to add a help function with some QT code, just an ordinary QString the DllImport starts throwing dllNotFoundException.dumpbin.exe shows all the exported functions as well after including the qt code...
main.cpp dllNotFoundException
#include <QString>
using namespace std;
class testa
{
public:
static char* test()
{
QString a = "hejsan";
return qString2Char(a);
}
static char* qString2Char(QString a)
{
return a.toUtf8().data();
}
};
This is called from the getText() function like this:
string returnBufferString;
extern "C" __declspec(dllexport) const char* getText()
{
returnBufferString = testa::test();
return returnBufferString.c_str();
}
When I try to access the dll from DllImport I get dllNotFoundException in the 2:nd part. How do I solve this? have I missed any dependencies or anything. My dll is build using msvc2010 compiler and the .pro file looks like this:
cDLL.pro
TEMPLATE = lib
CONFIG += dll
QT += core
# Input
SOURCES += main.cpp
I'm stuck...
It doesn't tell you exactly what DLL it cannot find. Which is almost surely not your DLL, it is one of the DLLs that QT requires. You'd have to copy them to the EXE folder as well. If you have no idea and can't find it in the Nokia documentation then you can find out with SysInternals' ProcMon utility.
However, in this scenario you surely want to link QT into your DLL since the odds that those DLLs can be shared are small. Use this SO question for guidance in setting up your QT project.
You need to put the DLL in the same folder as your executable.
See http://msdn.microsoft.com/en-us/library/windows/desktop/ms682586%28v=vs.85%29.aspx