|
Thanks for your atention...
At the beginning I thought that was the problem and decided to do something very basic for testings, but I still can not access to it.
For my testings I made:
//MyDll.cpp
#include "MyDll.h"
namespace Functions{
Person MyFunctions::first() {
struct Person myPerson;
myPerson.name = "asd";
myPerson.age = 123;
return myPerson;
}
}
//MyDll.h
namespace Functions{
struct Person {
char *name;
int age;
};
class MyFunctions {
public:
static __declspec(dllexport) Person first();
};
}
Then the DLL file I paste in the new project folder (only this one, because for my point of view I don't need nothing more, because it is very simple and doesn't use/depend nothing more ), right?
In the new project I made:
#include "stdafx.h"
#include "windows.h"
using namespace System;
int main(array<System::String ^> ^args){
HINSTANCE myDll = LoadLibrary((LPCWSTR)"TestingDll.dll");
if(myDll) {
Console::WriteLine("DLL loaded \n");
}
else {
Console::WriteLine("DLL failed to load \n");
}
return 0;
}
And the result always is -> "DLL failed to load".
It doesn't returns any error, but doesn't do what I want .
I apologize, but due to my inexperience I did not understand the problem that could cause this ( for sure is something that I'm doing wrong, or forget).
Can you help me?
|
|
|
|
|
From LoadLibrary documentation [^].
Return Value
If the function succeeds, the return value is a handle to the module.
If the function fails, the return value is NULL. To get extended error information, call GetLastError.
BTW possibly you should put the DLL inside the project folder.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
|
|
|
|
|
Thanks for your atention...
I already have the DLL inside the new project folder, but it still not work  and I couldn't understand what could be the cause of this, because it doesn't return any error...
|
|
|
|
|
As stated by the documentation I linked in my previous post, if the LoadLibrary return HANDLE is NULL then you have to call GetLastError in order to get some understanding of what's happening.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
|
|
|
|
|
Perhaps your quote on Creation could be applied to the other Lord who has created so many dialects of C with so many obscure confusions in syntax.
Regards
Ron
|
|
|
|
|
Maybe. Anyway, strictly speaking, the obstacles that are hurting the OP are functions of an application programming interface (Win32 API): he isn't dealing with a C language dialect.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
|
|
|
|
|
Again, CByteArray members GetData & GetSize (togheter with std::string constructor) do the trick, for instance:
CByteArray arr;
arr.Add(0xff);
arr.Add(0x00);
arr.Add(0x10);
arr.Add(0x41);
std::string str((char*) arr.GetData(), arr.GetSize());
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
|
|
|
|
|
Are you using Visual Studio 2005 or 2008?
You may notice that the Visual Studio puts your exe in a folder called "debug" at the same level as your project folder.
The "debug" folder that's inside your project folder holds only the obj files, and the exe does not run from there.
You have to make sure that you put the DLL into the same folder where the exe file is created.
Solution Folder<br />
|<br />
|---Project Folder<br />
| |<br />
| |-Debug<br />
|<br />
|---Debug <= Put dll here<br />
|
|
|
|
|
I'm using Visual Studio 2008.
I had been careful to paste the DLL in the folder with the .exe file... But it still doesn't work...
It is the first time I tried to do a DLL, it is possible I forgot something, or maybe I'm doing something wrong... 
|
|
|
|
|
Does your DllMain() function return TRUE?
A Dll will only load if its DllMain() function returns TRUE.
|
|
|
|
|
I think my DLL code is correct, because I used the DLL in a c# project and it loaded and worked just fine.
My problem is to load in a c++ project.
I read that if we want to use a DLL without de lib file, we must paste de DLL file in the debug project folder (and I did it, because I want it to work without the code files).
Then I used
HINSTANCE myDll = LoadLibrary((LPCWSTR)"Testing.dll");
if(myDll)
Console::WriteLine("DLL loaded \n");
else
Console::WriteLine("DLL failed to load \n");
it always "DLL failed to load ", it doesn't return any error.
Did I forgot something, or am I doing something wrong? (I'm starting with c++, so possible I'm making some mistake).
Thanks.
|
|
|
|
|
Change your code so that it reads as follows:
HINSTANCE myDll = LoadLibrary((LPCWSTR)"Testing.dll");
DWORD Error = GetLastError();
if (myDll)
Console::Writeline("Dll Loaded");
else
Console::Writeline("Dll Not Loaded");
Put a breakpoint at the line that says "Not Loaded."
When the program breaks, inspect the value of the variable Error.
That will be the Windows error code for what went wrong. Post the Error code here, and maybe we can help you figure it out.
|
|
|
|
|
Hi.
Thanks a lot for your help.
I did what you suggested and I got error 126 (unsigned int).
I made a litle search to understand error 126 and its causes...and I found out that I can't cast char* to LPCWSTR, and the solution is just "Use Multi-Byte Character Set" within the projects properties. And it works just fine.
Best regards,
Carla
|
|
|
|
|
Hi,
How do i convert a const string& to CByteArray ?
I have to convert the string to CByteArray and pass the member functions GetData() and GetSize() to a method as parameters
Is it possible or is there an alternative way of converting string to CByteArray.
An example would be appreciated.
Thanks in advance,
Regards,
Mayur M
|
|
|
|
|
Try (I didn't test it...)
CString str = _T("Hi");
CByteArray arr;
int iSize = (str.GetLength()+1) * sizeof(TCHAR)
const BYTE * pByte = (const BYTE *) (LPCTSTR) str;
for (i = 0; i < iSize; i++)
{
arr.Add(pByte[i]);
}
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
|
|
|
|
|
Thanks for your reply.
The code snippet works fine. But the snippet is for convertion of CString to CByteArray. But i'm looking for a const string conversion to CByteArray.
Even if i use the CString conversion to CByteArray, is there any inbuilt methods rather than using the for loop.
Regards,
Mayur M
|
|
|
|
|
mayur8u wrote: But i'm looking for a const string conversion to CByteArray.
Are you talking about std::string?
mayur8u wrote: Even if i use the CString conversion to CByteArray, is there any inbuilt methods rather than using the for loop.
Yes, you may use CByteArray methods SetSize and Getdata to copy the string content into the array buffer.
CString str = _T("Hi");
CByteArray arr;
int iSize = (str.GetLength()+1) * sizeof(TCHAR)
arr.SetSize(iSize);
const BYTE * pByte = (const BYTE *) (LPCTSTR) str;
CopyMemory( arr.GetData(), pByte, iSize);
As usual, the test is up to you.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
|
|
|
|
|
Ya! i'm talking about converting from std::string to CByteArray.
If there is no solution then i might have to go to CString. (Last option)
|
|
|
|
|
std::string str("Hi");
int iLen = str.length();
CByteArray arr;
arr.SetSize(iLen);
CopyMemory( arr.GetData(), str.c_str(), iLen);
Please note, the above code is not adding the null terminator at the tail of the array.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
|
|
|
|
|
How about the CByteArray to std:string?
|
|
|
|
|
Hi,
I'm able to convert const string& to CByteArray using the
memcpy(byteArr.GetData(), source.c_str(), source.length());
Does converting back the CByteArray to const string& work the same way using memcpy?
Regards,
Mayur M
|
|
|
|
|
char str[] = "abcdef";
int iSize = strlen(str);
BYTE * pByte = (BYTE *) str;
CByteArray arr;
for (int i = 0; i < iSize; i++)
{
arr.Add(pByte[i]);
}
the loop is must use.
|
|
|
|
|
I have a code written as:-
#include<string>
#include <iostream>
#include <iomanip>
using namespace std;
// This class Package is the base class for two other classes, TwoDayPackage and OverNightPackage.//
class Package // begins class Package
{
public:
Package(const string &, const string &, const string &, const string &, const string &, const string &, const string &, const string &, const string &, const string &, double = 0.0, double = 0.0); // constructor
// set and get functions for sender
void setSendName(const string &);
string getSendName() const;
void setSendAdd(const string &);
string getSendAdd() const;
void setSendCity(const string &);
string getSendCity() const;
void setSendSt(const string &);
string getSendSt() const;
void setSendZip(const string &);
string getSendZip() const;
// set and get functions for recipient
void setRecName(const string &);
string getRecName() const;
void setRecAdd(const string &);
string getRecAdd() const;
void setRecipientCity(const string &);
string getRecipientCity() const;
void setRecSt(const string &);
string getRecSt() const;
void setRecZip(const string &);
string getRecZip() const;
void setWt(double);
double getWt() const;
void setShip(double);
double Package::getShip() const
{
return shipCost;
}
double Package::CalCost() const
{
return (wt*shipCost);
}
private:
string sendName;
string sendAdd;
string sendCity;
string sendState;
string sendZip;
string recName;
string recAdd;
string recCity;
string recState;
string recZip;
double wt;
double shipCost;
};
Package::Package(const string &sname, const string &saddress, const string &scity, const string &sstate, const string &szipcode, const string &rname, const string &raddress, const string &rcity, const string &rstate, const string &rzipcode, double wt, double shipCost)
{
sendName = sname;
sendAdd = saddress;
sendCity = scity;
sendState = sstate;
sendZip = szipcode;
recName = rname;
recAdd = raddress;
recCity = rcity;
recState = rstate;
recZip = rzipcode;
setWt(wt);
setShip(shipCost);
}
void Package::setSendName(const string &sname)
{
sendName = sname;
}
string Package::getSendName() const
{
return sendName;
}
void Package::setSendAdd(const string &saddress)
{
sendAdd = saddress;
}
string Package::getSendAdd() const
{
return sendAdd;
}
void Package::setSendCity(const string &scity)
{
sendCity = scity;
}
string Package::getSendCity() const
{
return sendCity;
}
void Package::setSendSt(const string &sstate)
{
sendState = sstate;
}
string Package::getSendSt() const
{
return sendState;
}
void Package::setSendZip(const string &szipcode)
{
sendZip = szipcode;
}
string Package::getSendZip() const
{
return sendZip;
}
void Package::setRecName(const string &rname)
{
recName = rname;
}
string Package::getRecName() const
{
return recName;
}
void Package::setRecAdd(const string &raddress)
{
recAdd = raddress;
}
string Package::getRecAdd() const
{
return recAdd;
}
void Package::setRecipientCity(const string &rcity)
{
recCity = rcity;
}
string Package::getRecipientCity() const
{
return recCity;
}
void Package::setRecSt(const string &rstate)
{
recState = rstate;
}
string Package::getRecSt() const
{
return recState;
}
void Package::setRecZip(const string &rzipcode)
{
recZip = rzipcode;
}
string Package::getRecZip() const
{
return recZip;
}
void Package::setWt(double wt)
{
wt = (wt < 0.0 ) ? 0.0 : wt;
}
double Package::getWt() const
{
return wt;
}
void Package::setShip(double shipCost)
{
shipCost = ( shipCost < 0.0) ? 0.0 : shipCost;
}
// This class TwoDayPackage is the first derived class from class Package.//
class TDP : public Package
{
public:
TDP(const string &, const string &, const string &, const string &, const string &, const string &,
const string &, const string &, const string &, const string &, double = 0.0, double = 0.0, double = 0.0); // constructor
void setFlatFee(double);
double getFlatFee() const;
double CalCost() const;
private:
double flatFee;
};
// This class OverNightPackage is the second derived class from class Package.//
class ONP : public Package
{
public:
ONP(const string &, const string &, const string &, const string &, const string &, const string &, const string &, const string &, const string &, const string &, double=0.0, double=0.0, double=0.0); // constructor
void setFee(double);
double getFee() const;
double CalCost() const;
private:
double fee;
};
// This is the test program.//
int main()
{
ONP box("name", "123 this Street", "boston", "ma", "12345", "receiver", "123 that street", "medford", "ma", "25341", 10.00, 1.50, .85);
TDP parcel("name2", "123 1st Street", "orlando", "fl", "56474", "receiver2", "833 2nd Street", "miami", "fl", "88472", 15.00, 1.05, 5.00);
cout << fixed << setprecision(2);
cout << "To ship a box with overnight delivery\n";
cout << "The sender " << box.getSendName()<< "\n";
cout << " " << box.getSendAdd() << "\n";
cout << " " << box.getSendCity() << " " << box.getSendSt() << " " << box.getSendZip() << "\n";
cout << "The recipient " << box.getRecName()<< "\n";
cout << " " << box.getRecAdd() << "\n";
cout << " " << box.getRecipientCity() << " " << box.getRecSt() << " " << box.getRecZip() << "\n";
cout << "The cost is $ " <<box.CalCost() << "\n";
cout << "\n\n";
cout << "To ship a parcel with 2 day delivery\n";
cout << "The sender " << parcel.getSendName()<< "\n";
cout << " " << parcel.getSendAdd() << "\n";
cout << " " << parcel.getSendCity() << " " << parcel.getSendSt() << " " << parcel.getSendZip() << "\n";
cout << "The recipient " << parcel.getRecName()<< "\n";
cout << " " << parcel.getRecAdd() << "\n";
cout << " " << parcel.getRecipientCity() << " " << parcel.getRecSt() << " " << parcel.getRecZip() << "\n";
cout << "The cost is $ "<<parcel.CalCost() << "\n";
system("pause");
return 0;
}
The calcost function needs some change as it is the source of error.Somebody help.
modified on Monday, February 16, 2009 12:15 PM
|
|
|
|
|
Keep your question concise! No-one will want to read all of that to answer your question!
Regards,
--Perspx
"A refund for defective software might be nice, except it would bankrupt the entire software industry in the first year."
-Andrew Tanenbaum
"Einstein argued that there must be simplified explanations of nature, because God is not capricious or arbitrary. No such faith comforts the software engineer."
-Fred Brooks
|
|
|
|
|
Didn't this come out of Deitel's "C++: How to Program" book? Is this your assignment?
"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
|
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
