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Hello
I need help building a DLL using Visual Studio 6.0.
Our company has a statically liked library which (as expected) contains functions used by various applications. We want to be able to call some of these functions from managed code (C#) and as best as I can determine, having them exported from a DLL is the way to go about it. I have made this work, somewhat, in that I can create a trivial Windows DLL (i.e. non-MFC) having exported functions (in C, not C++) that I was able to invoke from a C# console application.
Because the static lib uses MFC stuff (CString, etc.), I created an MFC (AppWizard) DLL using VS 6.0, and simply added the various files from the static lib (Project > Add To Project > Files...). The files were not copied and added to the project anew; the DLL project simply refers to the files in the static lib's folder. The static lib files I am trying to compile consist of both C++ classes as well as global C functions, though mostly the latter.
After getting past numerous problems, I was able to successfully compile all of the files in this new DLL project. However the subsequent link operation tried to produce the DLL's .lib (export) file at which point I got a slew of "unresolved external symbol" errors. It looks like these could
be related to one or more of the following: C++ function name mangling, the calling convention (e.g. __cdecl), static data members, or global C functions/types. I listed several of the link errors below.
At any rate, I am stumpified at this point. If anyone can suggest a solution I would be most grateful.
Thanks!
Christopher Brack
C3-ilex, LLC
Trends.obj : error LNK2001: unresolved external symbol "protected: static class CString CDaoRecordsetEx::m_Log" (?m_Log@CDaoRecordsetEx@@1VCString@@A)
ACSUser.obj : error LNK2001: unresolved external symbol "protected: static class CString CDaoRecordsetEx::m_Log" (?m_Log@CDaoRecordsetEx@@1VCString@@A)
AlarmClass.obj : error LNK2001: unresolved external symbol "protected: static class CString CDaoRecordsetEx::m_Log"
(?m_Log@CDaoRecordsetEx@@1VCString@@A)
DaoRecordsetEx.obj : error LNK2001: unresolved external symbol "protected: static class CString CDaoRecordsetEx::m_Log"
(?m_Log@CDaoRecordsetEx@@1VCString@@A)
MapboardPointsSet.obj : error LNK2001: unresolved external symbol "protected: static class CString CDaoRecordsetEx::m_Log"
(?m_Log@CDaoRecordsetEx@@1VCString@@A)
AGC_Misc.obj : error LNK2001: unresolved external symbol "bool __cdecl ExecDecreaseThreadPriority(void *)" (?ExecDecreaseThreadPriority@@YA_NPAX@Z)
AGC_Misc.obj : error LNK2001: unresolved external symbol "bool __cdecl ExecIncreaseThreadPriority(void *)" (?ExecIncreaseThreadPriority@@YA_NPAX@Z)
DbAddDev.obj : error LNK2001: unresolved external symbol "union _tDB_ADDRESSES DB_PTRS" (?DB_PTRS@@3T_tDB_ADDRESSES@@A)
DbLoad.obj : error LNK2001: unresolved external symbol "union _tDB_ADDRESSES DB_PTRS" (?DB_PTRS@@3T_tDB_ADDRESSES@@A)
DbRetDev.obj : error LNK2001: unresolved external symbol "union _tDB_ADDRESSES DB_PTRS" (?DB_PTRS@@3T_tDB_ADDRESSES@@A)
DbAccess.obj : error LNK2001: unresolved external symbol "enum Ctr_e_LMTy * DbTyTOLMTy" (?DbTyTOLMTy@@3PAW4Ctr_e_LMTy@@A)
DbAddDev.obj : error LNK2001: unresolved external symbol "enum Ctr_e_LMTy * DbTyTOLMTy" (?DbTyTOLMTy@@3PAW4Ctr_e_LMTy@@A)
DbLoad.obj : error LNK2001: unresolved external symbol "unsigned short * CUS_DIR_STR" (?CUS_DIR_STR@@3PAGA)
StInit.obj : error LNK2001: unresolved external symbol "unsigned short * CUS_DIR_STR" (?CUS_DIR_STR@@3PAGA)
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Hello,
I'm having a problem with a CScrollView in a CSplitterWnd. It doesn't respond to any keyboard commands (WM_KEYDOWN) or to WM_MOUSEWHEEL. The CSplitterWnd is a 1 row, 2 col splitter. The left side (0,0) is a CFormView and the right side (0,1) is the CScrollView (CMessageView : CScrollView). Unfortunately CMessageView originally inherited from just a CView and I later changed it to inherit from CScrollView by manually changing all the CView references to CScrollView, except where there was a pointer to CView. This may be an underlying cause to the problem.
Anyway the scrollview responds properly to the use of the scrollbars, but doesn't respond to the keyboard or mousewheel. I've been able to determine that the CMessageView does indeed have focus and that it does in fact receive WM_MOUSEWHEEL commands. I haven't tried WM_KEYDOWN commands, but I suspect that it will respond to them as well.
Does anyone have any ideas on what I'm doing wrong? Or some suggestions on other things to try? I've googled on this for quite a while now and nothing that I've found seems to work. I thought that a CScrollView was supposed to automatically work with mouse wheels and the keyboard.
Thanks in advance for any help.
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Write a program which outputs frequency of digits in a given integer. For example, if the number is 12424329, output will be
Number Frequency
1 (space) 1
2 (space) 3
3 (space) 1
4 (space) 2
9 (space) 1
Use a switch statement to obtain frequency of the digits.
im goin to try and work on it right now and see if i can get through just asking for alittle help thanks...
(space) doesn't mean anything just to make the numbers line up
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Reading your exam question properly is probably a good start. Learning how to Copy and Paste it on this Message Board would count as a good second, at least people would know what the question is about, A good Third would be to realise that this message board is NOT about doing your exam work for you, Point four is, If you ask a question that NoOne can understand, Don't expect a sebsible answer.
Moral of the story: Read Books about CPP,C,Operating Systems, Anything you can get your hands at.Alternatively, Enroll in a Course and hang on to every word said. They call that Studying.
When you're finished doing reading and doing courses, Read More Books, Enroll to More courses. There's No Shortcut to Knowledge.
LateNightsInNewry
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I think I provided you with the logic[^] a day or two before.
Somethings seem HARD to do, until we know how to do them.
 _AnShUmAn_
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#include "stdafx.h"
#include <iostream>
#include <iomanip>
using namespace std;
int n, temp, count0 = 0, count1 = 0, count2 = 0, count3 = 0, count4 = 0, count5 = 0, count6 = 0, count7 = 0, count8 = 0, count9 = 0;
int main()
{
cout << "Enter the number to be evaluated." << endl;
cin >> temp;
while (temp != 0){
n=temp%10;
switch(n){
case 0: count0++;
break;
case 1: count1++;
break;
case 2: count2++;
break;
case 3: count3++;
break;
case 4: count4++;
break;
case 5: count5++;
break;
case 6: count6++;
break;
case 7: count7++;
break;
case 8: count8++;
break;
case 9: count9++;
break;
}
temp = temp / 10;
}
cout << " Answer is " << endl;
if(count0>0)
cout<< "0" << " " << count0 << endl;
if(count1>0)
cout<< "1" << " " << count1 << endl;
if(count2>0)
cout<< "2" << " " << count2 << endl;
if(count3>0)
cout<< "3" << " " << count3 << endl;
if(count4>0)
cout<< "4" << " " << count4 << endl;
if(count5>0)
cout<< "5" << " " << count5 << endl;
if(count6>0)
cout<< "6" << " " << count6 << endl;
if(count7>0)
cout<< "7" << " " << count7 << endl;
if(count8>0)
cout<< "8" << " " << count8 << endl;
if(count9>0)
cout<< "9" << " " << count9 << endl;
return 0 ;
}
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<code>
int _tmain(int argc, _TCHAR* argv[])
{
int number;
cout<<"Please enter the number-";
cin>>number;
int temp,r;
int count=0;
bool numberFound=false;
for(int i=0;i<=9;i++)
{
count=0;
temp=number;
while(temp!=0)
{
r=temp%10;
temp=temp/10;
if(r==i)
{
count++;
}
}
if(count>0)
cout<<i<<" " <<count<<endl;
}
return 0;
}
You can modify this to use switch case
Somethings seem HARD to do, until we know how to do them.
_AnShUmAn_
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i think it right im just checking...
and i did copy it and paste it right...
#include "stdafx.h"
#include <iostream>
#include <iomanip>
using namespace std;
int n, temp, count0 = 0, count1 = 0, count2 = 0, count3 = 0, count4 = 0, count5 = 0, count6 = 0, count7 = 0, count8 = 0, count9 = 0;
int main()
{
cout << "Enter the number to be evaluated." << endl;
cin >> temp;
while (temp != 0){
n=temp%10;
switch(n){
case 0: count0++;
break;
case 1: count1++;
break;
case 2: count2++;
break;
case 3: count3++;
break;
case 4: count4++;
break;
case 5: count5++;
break;
case 6: count6++;
break;
case 7: count7++;
break;
case 8: count8++;
break;
case 9: count9++;
break;
}
temp = temp / 10;
}
cout << " Answer is " << endl;
if(count0>0)
cout<< "0" << " " << count0 << endl;
if(count1>0)
cout<< "1" << " " << count1 << endl;
if(count2>0)
cout<< "2" << " " << count2 << endl;
if(count3>0)
cout<< "3" << " " << count3 << endl;
if(count4>0)
cout<< "4" << " " << count4 << endl;
if(count5>0)
cout<< "5" << " " << count5 << endl;
if(count6>0)
cout<< "6" << " " << count6 << endl;
if(count7>0)
cout<< "7" << " " << count7 << endl;
if(count8>0)
cout<< "8" << " " << count8 << endl;
if(count9>0)
cout<< "9" << " " << count9 << endl;
return 0 ;
}
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Hello all,
small problem with a simple app.
Its a simple Mp3 player app (simultation only). I have an MP3 Class that appears to load fine. It crashes out when I call the PrintMP3Details() function in Mp3.h. I get part of the output ie:
I'd really appreciate any help that anyone could provide - I've asked my lecturer four times over the past 7 days and he hasn't even replied... 
Thanks in advance - Much appreciated.
"
Track 0 Contains:
Artist : BOMBS OUT HERE.....
"
MP3Player.Cpp
#include <fstream><br />
#include <iostream><br />
#include "mp3.h"<br />
<br />
using namespace std;<br />
int main (void)<br />
{<br />
int length, count, iNo, menu, loop;<br />
char str[80], fil[80], track[80], artist[80];<br />
count = 0;<br />
string filename;<br />
cout << "Welcome to the MP3 player" << endl;<br />
cout << "please enter filename (playlist.txt is default)" << endl;<br />
cin >> fil;
ifstream in(fil);
if(!in)
{ <br />
cout << "Cannot open file.\n" << endl; <br />
} <br />
while(!in.eof())
{<br />
in >> artist;
in >> track;
in >> length;
count++; <br />
} <br />
cout << endl;<br />
iNo=count;
<br />
cout << endl <<"File contains " << count << " files." << endl;
in.close();
Mp3 *Playlist[iNo];
count = 0;
ifstream in2(fil);
if(!in)
{ <br />
cout << "Cannot open file.\n" << endl; <br />
} <br />
cout << "marker " << endl;<br />
while(!in.eof()) <br />
{<br />
in2 >> artist;
in2 >> track;
in2 >> length;
count++; <br />
Playlist[count] = new Mp3(artist, track, length); <br />
cout << count << " contains " << artist << track << length << endl; <br />
} <br />
cout << endl;<br />
in.close();<br />
<br />
<br />
<br />
<br />
while (menu !=0){<br />
cout << "Please select from the following..." << endl<br />
<< "1) Print playlist (currently loaded)" << endl<br />
<< "0) Close MP3 player " <<endl << endl;<br />
cin >> menu;<br />
cout << endl; <br />
<br />
switch (menu)<br />
{<br />
case 1:<br />
for (int loop=0; loop<iNo;loop++)<br />
{<br />
cout << "Track " << loop << " Contains : " << endl;<br />
Playlist[loop]->PrintMP3Details();<br />
cout << endl << endl;<br />
}<br />
break;<br />
<br />
case 2:<br />
break;<br />
return 0; <br />
}
}
}
MP3.h
<br />
#include <fstream><br />
#include <iostream><br />
using namespace std;<br />
<br />
class Mp3<br />
{ <br />
private<br />
:<br />
string Artist;<br />
string Track;<br />
int Length;<br />
<br />
public:<br />
<br />
Mp3::Mp3(string Nartist, string Ntrack, int Nlength)<br />
{<br />
Artist = Nartist;<br />
Track = Ntrack;<br />
Length = Nlength; <br />
}<br />
<br />
string GetArtist()const {return Artist;}<br />
string GetTrack()const {return Track;}<br />
int GetLength()const {return Length;}<br />
<br />
void SetArtist (string strArtist) {Artist = strArtist;}<br />
void SetTrack (string strTrack) {Track = strTrack;}<br />
void SetLength (int iLength) {Length = iLength;}<br />
<br />
void PrintMP3Details() <br />
{<br />
cout << "Artist : " << Artist << endl<br />
<< "Track : " << Track << endl<br />
<< "Length : " << Length << endl;<br />
}<br />
};
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I think the problem is the following:
count++;
Playlist[count] = new Mp3(artist, track, length);
Try this:
Playlist[count] = new Mp3(artist, track, length);
count++;
Or this:
Playlist[count++] = new Mp3(artist, track, length);
The first is wrong because you start by filling in Playlist[1] instead of PlayList[0]. Also at the end you will be filling in slot Playlise[iNo], which does not exist. As a further check in your loop, you may what to use while( !in.eof() && count < iNo ) as additional safety; although the way it is written now, that will not help.
The actual cause of an error is not always reported when it occurs, so remember to work backwards from the error (what happen before it).
P.S. Prefer ++count to count++, because if those operators are ever overload the difference will give you headaches.
INTP
"Program testing can be used to show the presence of bugs, but never to show their absence."Edsger Dijkstra
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If you want to play mp3 files you can also use of MCI functions.
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Basically what I am trying to do is have two text strings pop in text boxes (CEdit) for the user when they open a dialog box. The problem is that when you call domodal, all control transfers to the dialog box, so everything has to be done before the call. In the past I have just set a flag in the dialog box class to let it know that something needs to be loaded, and placed the information there beforehand, and then called domodal. OnInitDialog gets called when the dialog pops up, checks for the flag, and loads whatever. It seems kind of messy though. Is there another more elegant way to do it? Is there some way I can modify DoModal to accept arguments?
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have you seen This[^] article ?
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Along these same lines, do you know how to put carriage returns into the CEdit? Yeah, I know, noob question, but I haven't worked much with CStrings and CEdit controls, and I just realized that putting a "\n" into a char buffer then converting it to a CString won't work in a CEdit...how do I do this?
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that did the trick...thanks...seems counterintuitive, like I was programming for unix or something...I never even would have guessed that in a million years...
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Also, a totally unrelated way of doing this, but may be of use if you're using a DLL, is to create a shared data segment with #pragam data_seg() and put in a global variable in there which will keep track of the number of instances of subscribers to the DLL. Of course your program will have to import the DLL etc, which is not preferable at all, but like I said if you're already using a DLL it's another option.
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globals are most of the time bad, and can be avoided using OOP data members.
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I made that post in the wrong thread...my bad
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Right now, We have a ClxThreadClass that provides the capablity to create single worker thread for the class that inherits it. The function below shows the class member function that creates and starts the new thread. The desire worker code reside in _ThreadFunc.
<br />
<br />
The Current working design<br />
<br />
bool ClxThreadClass::CreateNewThread()<br />
{<br />
if( m_hThread == NULL )<br />
{<br />
m_hThread = (HANDLE)_beginthreadex(NULL, 0,_ThreadFunc, this, CREATE_SUSPENDED, &uiThreadId); <br />
if ( NULL != m_hThread)<br />
{<br />
ResumeThread( m_hThread );<br />
m_bActive = true;<br />
return true;<br />
}else{<br />
m_bActive = false;<br />
}<br />
}<br />
<br />
return true;<br />
}<br />
However, We sometimes would like to use different function other than _ThreadFunc. How can we overload CreateNewThread member function to take an external and pass to beginthreadex. This external obect is not a member function of base or inherited class.
<br />
bool ClxThreadClass::CreateNewThread( void *ptr )<br />
{<br />
<br />
if( m_hThread == NULL )<br />
{<br />
m_hThread = (HANDLE)_beginthreadex(NULL, 0, ptr, this, CREATE_SUSPENDED, &uiThreadId); <br />
if ( NULL != m_hThread)<br />
{<br />
ResumeThread( m_hThread );<br />
m_bActive = true;<br />
return true;<br />
}else{<br />
m_bActive = false;<br />
}<br />
}<br />
return true;<br />
<br />
}<br />
Scott Dolan
Jernie Corporation
Engineering & Manufacturing
Software, Hardware, & Enclosures
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Maybe something like this:
typedef unsigned (__stdcall *PTHREADFUNC)(void *);
...
bool ClxThreadClass::CreateNewThread(PTHREADFUNC pThreadFunc)
{
if( m_hThread == NULL )
{
m_hThread = (HANDLE)_beginthreadex(NULL, 0, pThreadFunc, this, CREATE_SUSPENDED, &uiThreadId);
...
}
"Great job, team. Head back to base for debriefing and cocktails."
(Spottswoode "Team America")
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Mark Salsbery wrote: typedef unsigned (__stdcall *PTHREADFUNC)(void *);
if this function points to global function, it will work .. if it point to class member function.. then there would be some trouble.. i.e. we have to change the Funtion ptr declaration and pass the pointer of the class to that function!
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Right. The OP stated "This external obect is not a member function of base or inherited class"
which soundedread like it wasn't a class method to me.
Mark
"Great job, team. Head back to base for debriefing and cocktails."
(Spottswoode "Team America")
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Mark Salsbery wrote: he OP stated "This external obect is not a member function of base or inherited class"
which soundedread like it wasn't a class method to me.
oops my mistake.. it seems work is taking over me [ ]
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Hi,
Can someone help me?
Im just trying to get a list of all windows users names in a local computer.
GetUserName gives us just the current user:
BOOL GetUserName(
LPTSTR lpBuffer,
LPDWORD lpnSize
);
but I dont know  how can I get all the other users in the same machine.
Thanks.
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