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See the Winsock Programmer's FAQ[^].
In your particular case I would recommend using blocking sockets, but on a worker thread instead of in your main user interface thread.
Stability. What an interesting concept. -- Chris Maunder
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I need to render a pdf and also need to give a page turning effect(flip) when user changes pages via mouse pointer.
For this effect, I need to use some rendering library either OpenGL, DirectX or GDI.
I want to know how easily can this effect be implemented.
I mean if this can be done via some affine transformation what possible steps will be required.?
or is something other than plain transformation is required what possible steps shall those be?
It is an urgent requirement so i need "Instant Help" 
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I am trying to convert from Visual Studio 6 to vs7 (NET) and
am having problems with HtmlHelp. In vs6 HtmlHelp took 4
parameters, whereas in vs7, it won't compile unless it has 2
parameters (see code):
case HELP_FINDER:
#if vs7
HtmlHelp( 0, HH_DISPLAY_TOPIC);
#else
HtmlHelp( m_pMainWnd->m_hWnd, "petctviewer.chm", HH_DISPLAY_TOPIC, 0);
#endif
return;
In vs6, I have it pointing to a compiled help file and all
works well. In vs7, I noticed it brought up an old *.hlp
file which I happened to have still on my disk. It ignored
the *.chm which it uses in vs6.
If I look at the Microsoft documentation, it indeed talks
about the version with 2 parameters, but then if you go to
the SDK it has 4 parameters. Somewhat confusing....
In short, does anyone know how to convince vs7 to use the
4 parameter version of HtmlHelp?
Thanks,
Ilan
Ilan
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I think you're getting caught by the addition of the CWnd::HtmlHelp and CWinApp::HtmlHelp methods in MFC 7. To ensure you call the global, API call, use the :: scope resolution operator:
::HtmlHelp( m_pMainWnd->m_hWnd, "petctviewer.chm", HH_DISPLAY_TOPIC, 0); If you want to use the MFC wrappers, you need to set your application (CWinApp-derived) object's m_pszHelpFilePath to the path of your help file and call EnableHTMLHelp.
Stability. What an interesting concept. -- Chris Maunder
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Mike,
Thanks for the very clear explanation.
1) the code works
2) I now understand the "mystery" of why it was working the way it was.
Ilan
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suppose i have a class as follows:
class X
{
HANDLE hThread;
public:
X();
UINT ThreadProc(LPVOID lpVoid);
};
now in the constructor X(), i call the function CreateThread() as follows:
hThread = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)ThreadProc,NULL,0,NULL);
i get the following error:
error C2440: 'type cast' : cannot convert from 'overloaded-function' to 'LPTHREAD_START_ROUTINE'
Even if i do the following, i get the same error
hThread = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)(X::ThreadProc),NULL,0,NULL);
I dont want to use a global function ThreadProc() because i want to access data members of the current object of the class X. So even using friend wont help in this case. Even passing of parameter to ThreadProc LPVOID parameter results in certain type incompatibilities.
Any workarounds ??
Please Help..
Nikhil
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Hello Nikhil,
It is not possible to use a member function as the Thread Startup function in a call to CreateThread(). CreateThread() expects either a global function or a class static function. The "static" keyword must be used when declaring your thread startup function, e.g. :
class X
{
protected :
HANDLE hThread;
public:
X();
protected :
static DWORD WINAPI ThreadProc(LPVOID lpParameter);
};
By being attributed as "static", ThreadProc() is actually a global function albeit it is within the X namespace and you may also set it as a protected function so that it cannot be accessed outside the X namespace.
One word of advise, Nikhil : avoid creating your thread inside your constructor. It is not advisable because of problems which may occur due to the order of object creation. Another complication which may arise is when virtual functions get involved.
These are not serious concerns if your "X" class is kept simple with no class derivation and no virtual functions. For more information, you may refer to my article : "The Importance of Sequence Order in the Creation of C++ Objects" :
http://www.codeproject.com/tips/OrderOfObjectCreation.asp[^]
Thanks,
Bio.
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Hello Nikhil,
Also, when you call CreateThread(), you may pass a pointer to your X instance as follows :
hThread = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)(ThreadProc),this,0,NULL);
Note the "this" is passed as the 4th parameter to CreateThread().
Then, in ThreadProc(), you may cast the input parameter back to an X pointer, e.g. :
DWORD WINAPI X::ThreadProc(LPVOID lpParameter)
{
X* pX = (X*)lpParameter;
DWORD dwRet = 0;
return dwRet;
}
Note that because ThreadProc(), although a "global" function, is within the X namespace and so may access the private or protected members of an X instance.
For example :
class X
{
protected :
HANDLE hThread;
private :
int m_i;
public:
X();
protected :
static DWORD WINAPI ThreadProc(LPVOID lpParameter);
};
Note that m_i is "private". But your ThreadProc() function may access X::m_i :
DWORD WINAPI X::ThreadProc(LPVOID lpParameter)
{
X* pX = (X*)lpParameter;
DWORD dwRet = 0;
pX -> m_i = 100;
return dwRet;
}
Hope the above helps, Nikhil.
Best Regards,
Bio.
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I am currently working on a graphical program in which I would like to use GDI+ (due to some of the extended functionality). I am a little confused on managing resources in the GDI+ framework. When working w/ MFC will resources such as Pens, Brushes, etc. clean themselves up or do I still have to manually delete these objects?
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does anyone a complete source code for adding, deleting and changing elements in an array in visual C++. Thanks
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Hi:
I just reinstalled my system and keep getting an error when I try to debug a DirectShow filter I'm developing. It says "Protection error: debugger detected" and it won't run. I think it's my webcam's filter that won't run, it thinks I'm runnig SoftIce or some cracking software.
Is there a way to avoid this? Any clue?
Thanks,
Aritosteles
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Ok, I found it's not my webcam filter. When I use the RenderFile() method of IGraphBuilder interface the same thing happens. Anyone's seen this?
Thanks,
Aritosteles
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Hi!
How can I use one in Visual BASIC developed DLL in Visual C ++?
This DLL contains several classes which I want to use in mine C ++ program. DLL is registered.
At the moment I do the following:
#import "ConvetHTML2WORD.dll"
using namespace ConvertHTML2WORD;
....
....
....
_CConvertHTML2WORDPtr ptrConvert; //CConvertHTML2WORD is a class from a VB6 DLL
HRESULT hr = ptrConvert.CreateInstance("ConvertHTML2WORD.CConvertHTML2WORD");
//"ConvertHTML2WORD.CConvertHTML2WORD" is a registry key in the registry
The CreateInstance does not function.
ptrConvert it remains NULL
what do I do to wrong?
Thnks, Nikolai
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What's the value of hr?
If you use the hr format in the Watch window (type hr,hr) the debugger will convert to the symbolic name for you.
Stability. What an interesting concept. -- Chris Maunder
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hello
I have a little problem with a dll
I am tying to hook some processes with a variable in a dll.
The variable should hold the names of all the path for the hooked processes. I have shared the variable everything is OK but when I try to initialize it from a file (because I read the entryies from a file) the callback function for the hook runs wild and I do not get the correct modulefilenames. All I get is my program's module filename.
I was wondering what is wrong.
here is a piece of code:
//globals
struct pr<br />
{<br />
char nume[1024];<br />
};<br />
<br />
#pragma data_seg("SHARED")<br />
HHOOK cbt=0;<br />
pr procs[100];<br />
int cnt=0;<br />
#pragma data_seg()<br />
#pragma comment(linker, "/section:SHARED,RWS")<br />
<br />
<br />
LRESULT CALLBACK CallWndProc(int nCode,WPARAM wParam,LPARAM lParam)<br />
{<br />
<br />
if (nCode<0)<br />
return CallNextHookEx(cbt,nCode,wParam,lParam);<br />
<br />
CWPSTRUCT *wps = (CWPSTRUCT*)lParam;<br />
<br />
<br />
DWORD pid;<br />
GetWindowThreadProcessId((HWND)wps->hwnd,&pid);<br />
HANDLE hProc;<br />
hProc=OpenProcess(PROCESS_ALL_ACCESS,FALSE,pid);<br />
HMODULE mods[100];<br />
DWORD size;<br />
char nume[1024];<br />
<br />
<br />
if (EnumProcessModules(hProc,mods,sizeof(mods),&size))<br />
if (size>0)<br />
GetModuleFileNameEx(hProc,mods[0],nume,sizeof(nume));<br />
<br />
<br />
<br />
CreateMutex(0,0,"Pula");<br />
if (GetLastError()!=ERROR_ALREADY_EXISTS)<br />
{<br />
CreateMutex(0,0,"Pula");<br />
FILE *str;<br />
char temp[1024];<br />
GetTempPath(sizeof(temp),temp);<br />
strcat(temp,"\\IdleProcesses.sys");<br />
str=fopen(temp,"a+");<br />
int i;<br />
i=0;<br />
while(!feof(str))<br />
{<br />
i++;<br />
fgets(temp,sizeof(temp),str);<br />
temp[strlen(temp)-1]='\0';<br />
strcpy(procs[i].nume,temp);<br />
<br />
}<br />
fclose(str);<br />
cnt=i;<br />
}<br />
<br />
<br />
<br />
<br />
for (int i=1; i<=cnt; i++)<br />
<br />
<br />
if (StrStrI(nume,procs[i].nume)!=NULL)<br />
{<br />
DWORD exit;<br />
GetExitCodeProcess(hProc,&exit);<br />
TerminateProcess(hProc,exit);<br />
}<br />
<br />
<br />
return CallNextHookEx(cbt,nCode,wParam,lParam);<br />
<br />
}<code>
gabby
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Hello,
I am working with tab controls and I would like to know if when a user selects a tab if you also have to hide the other tabs?
In my example there are two tabs here is the code that i am using the for loop works the code below the for loop does not. the only difference i can see is that in the for loop code i am hiding and showing and the code further down is only showing. does anyone have any comments or suggestions?
TCITEM tcItem;
for(int i = 0; i < m_TabCtrl.GetItemCount(); i++)
{
if (i != m_TabCtrl.GetCurSel())
{
m_TabCtrl.GetItem(i, &tcItem);
m_pDlg = (CMyDlg*) tcItem.lParam;
m_pDlg->ShowWindow(SW_HIDE);
}
}
m_TabCtrl.GetItem(m_TabCtrl.GetCurSel(), &tcItem);
m_pDlg = (CMyDlg*) tcItem.lParam;
m_pDlg->ShowWindow(SW_SHOW);
*pResult = 0;
}
// THIS CODE DOES NOT WORK IT IS SUCCESSFUL IN GETTING THE HWND BUT IT DOES NOT PROPERLY HIDE AND SHOW. I AM CURIOUS TO KNOW WHY I DIDN'T THINK THAT IT WAS NECESSARY TO HIDE THE WINDOWS AS WELL BUT I AM BEGINNING TO THINK THAT IT IS NECESSARY BECAUSE THAT IS WHAT THE CODE ABOVE DOES?
int Index = m_TabCtrl.GetCurSel();
m_TabCtrl.GetItem(Index, &tcItem);
CMyDlg* pDlg = (CMyDlg*) tcItem.lParam;
pDlg->ShowWindow(SW_SHOW);
Thanks,
Lino
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Is it possible to use Visual Studio .Net (7.1) for the generation of Web pages, or is it much better to use something like DreamWeaver. The pages will have quite a bit of I/O controls in them; e.g. buttons, edit boxes etc.
Someone said that you can edit html files (and asp files) in Visual Studio.
I did have a look, but what type of project do you specify if it is possible to have a series of Web pages as a project.
Also whats the difference between html and asp files and does it matter what you use in Visual Studio.
grahamfff
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I use VS6 for all my needs...but just the code editor...nothing WYSIWYG...
It's frustrating being a genius and living the life of a moron!!!
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SetMapMode (hdc, MM_ISOTROPIC) ;
SetWindowExtEx (hdc, 276, 72, NULL) ;
SetViewportExtEx (hdc, cxClient, cyClient, NULL) ;
SetWindowOrgEx (hdc, 138, 36, NULL) ;
SetViewportOrgEx (hdc, cxClient / 2, cyClient / 2, NULL) ;
Can anybody gives me a fully step by step explanation about the codes above, why the logical point (0,0) become the way it is?
Or give me a link to resources that can clarify the "SetWindowExtEx,SetWindowExtEx, SetWindowOrgEx,, SetViewportOrgEx" in much easy understanding way?These problem really bother me a lot!
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/*The Compiler errors is:
fatal error C1070 mismatched #if/#endif pair in file '**/*/****'
hope you can help!*/
#ifndef _WINSOCK2_H
#define _WINSOCK2_H
#define _GNU_H_WINDOWS32_SOCKETS
#ifdef __cplusplus
extern "C" {
#endif
#include <winsock.h>
#define FD_MAX_EVENTS 10
#define FD_READ_BIT 0
#define FD_WRITE_BIT 1
#define FD_OOB_BIT 2
#define FD_ACCEPT_BIT 3
#define FD_CONNECT_BIT 4
#define FD_CLOSE_BIT 5
typedef struct _WSANETWORKEVENTS {
long lNetworkEvents;
int iErrorCode[FD_MAX_EVENTS];
} WSANETWORKEVENTS, *LPWSANETWORKEVENTS;
typedef HANDLE WSAEVENT;
#define WSACreateEvent() CreateEvent(NULL, TRUE, FALSE, NULL)
/* etc */
int WINAPI WSAEnumNetworkEvents(SOCKET s, WSAEVENT hEventObject, LPWSANETWORKEVENTS lpNetworkEvents);
int WINAPI WSAEventSelect(SOCKET s, WSAEVENT hEventObject, long lNetworkEvents);
//ifdef __cplusplus
#endif
#endif
#endif
#endif
#endif
}
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there are too many #endif ...
you need to have one #endif per #if ( or #ifdef or #ifndef )
at the end you should have something like :
#ifdef __cplusplus
}
#endif
#endif
Maximilien Lincourt
Your Head A Splode - Strong Bad
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Thx. It worked on the file but now errors have appeard every were. I have an error in the tchar.h file, atalloc.h. I meen these files
weree made by Microsoft! Whot's happening here!
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