I'm new here, but always found help in the past.
I'm facing a strange problem with a simple block of code:
UINT ThreadMain(LPVOID pParam)
{
SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL);
THREADDATA* pData = (THREADDATA*) pParam;
INT* pnEditBoxValue = pData->pnEditBoxValue;
UINT nEid = pData->nEditId;
PLC *parent = (PLC*)pParam;
bool trigger_basso = false;
m_thread_running = 1;
CDeCoMotorDlg* wnd = pData->pObjDlg;
while(m_keep_alive==1)
{
SleepEx(1, 0);
wnd->CheckDlgButton(nEid, TRUE);
}
m_thread_running = 0;
return 0;
}
The problem seems related to this line:
wnd->CheckDlgButton(nEid, TRUE);
The lines works well (a check box is set on the gui), BUT, if I press a button on my GUI that sets the
m_keep_alive = 0
then the function stop working immediately: I don't see the while loop terminating properly and I never reach this line:
m_thread_running = 0;
What's strange is the if I remove this line
wnd->CheckDlgButton(nEid, TRUE);
the while loop exits properly, the flag is set and the thread exit properly...
I'm getting crazy...any suggestion?
Many thanks
Related
We have an MFC application that has been used and maintained for many years. Recently we made some administrative changes to some computers that are running the application. Now the software occasionally crashes when printing from the application.
We are using pretty standard MFC code to initiate the printing. We added try/catch blocks around what we felt like are the pertinent areas of the code with no luck. Whatever is failing does not seem to throw.
We get the typical dialog stating that "____ MFC Application has stopped working". Closing the program is the only option.
The windows event logger shows that our application is the Faulting application.
The exception code is 0xc0000005, which appears to be an Access Denied error.
The application is in the CView::OnFilePrint() code when the crash occurs.
We have added some logging, and we know that we get through DoPreparePrinting, and OnBeginPrinting.
We believe that CDC::StartDoc would be the next thing called, then CView::OnPrepareDC. We don't get to OnPrepareDC when we fail.
We don't seem to find the source code for CView::OnFilePrint, so we are not sure what it looks like. From research online, we think that things happen in this order in OnFilePrint:
// what we think is in OnFilePrint:
CView::OnFilePrint()
{
OnPreparePrinting(); <- we get through our override of this
OnBeginPrinting(); <- we get through our override of this
// loop back to here on multiple docs
CDC::StartDoc();
CView::OnPrepareDC(); <- we do not reach our override of this
CView::OnPaint();
CDC::EndPage();
// loop back on multiple docs
...
// finish if last doc...
}
I would like to have the source for it so we could attempt to rewrite it and try to gracefully fail instead of failing by crashing.
I'm looking for:
1) any suggestions as to how to figure out why the process of printing causes our application to crash.
2) A location for where the CView::OnFilePrint code is located, if available.
(the only idea I have left to narrow down the problem is to call our own version of this so that we can step through it and add logging and/or see if we can at least fail gracefully when it the problem occurs.)
The printer is Xerox Phaser 3610, for what its worth.
source code for CView::OnFilePrint should be in C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\atlmfc\src\mfc\viewprnt.cpp, depending on VS version. There could also be a problem with printer initialization/access.
If there is any error it is most likely due to printer initialization. You can override OnFilePrint and add CPrintInfo printInfo for testing. Example:
//ON_COMMAND(ID_FILE_PRINT, &CView::OnFilePrint)
//ON_COMMAND(ID_FILE_PRINT_DIRECT, &CView::OnFilePrint)
ON_COMMAND(ID_FILE_PRINT, OnFilePrint)
ON_COMMAND(ID_FILE_PRINT_DIRECT, OnFilePrint)
void CMyView::OnFilePrint()
{
try
{
CPrintInfo printInfo;
}
catch(...)
{
//log error
AfxMessageBox(L"error");
}
CView::OnFilePrint();
}
As noted in comments, another possibility is that there is a bug somewhere else in the code, which may not necessarily be related to printing.
Inside of CView::OnFilePrint, this occurs:
CWnd * hwndTemp = AfxGetMainWnd();
It turns out that if you don't call OnFilePrint from the main thread, this returns NULL.
Due to slight timing changes when the computers were logged onto a domain, OnFilePrint was being called from another thread. This causes the above call to return null, then when this line gets executed:
hwndTemp->EnableWindow(FALSE);
The application crashes.
There are several ways to fix this. One is to use this:
CWnd * hwndTemp = AfxGetApp()->GetMainWnd();
In place of this:
CWnd * hwndTemp = AfxGetMainWnd();
Another way is to assure that OnFilePrint is only called from the main thread.
A cut to the chase version of the code in CView::OnFilePrint is here:
// disable main window while printing & init printing status dialog
// Store the Handle of the Window in a temp so that it can be enabled
// once the printing is finished
CWnd * hwndTemp = AfxGetMainWnd(); // <--- CAN RETURN NULL HERE
hwndTemp->EnableWindow(FALSE); // <--- CRASH WILL OCCUR HERE
CPrintingDialog dlgPrintStatus(this);
Full version of CView::OnFilePrint is below.
The OnFilePrint code, with the problem area noted:
void CView::OnFilePrint()
{
// get default print info
CPrintInfo printInfo;
ASSERT(printInfo.m_pPD != NULL); // must be set
if (LOWORD(GetCurrentMessage()->wParam) == ID_FILE_PRINT_DIRECT)
{
CCommandLineInfo* pCmdInfo = AfxGetApp()->m_pCmdInfo;
if (pCmdInfo != NULL)
{
if (pCmdInfo->m_nShellCommand == CCommandLineInfo::FilePrintTo)
{
printInfo.m_pPD->m_pd.hDC = ::CreateDC(pCmdInfo->m_strDriverName,
pCmdInfo->m_strPrinterName, pCmdInfo->m_strPortName, NULL);
if (printInfo.m_pPD->m_pd.hDC == NULL)
{
AfxMessageBox(AFX_IDP_FAILED_TO_START_PRINT);
return;
}
}
}
printInfo.m_bDirect = TRUE;
}
if (OnPreparePrinting(&printInfo))
{
// hDC must be set (did you remember to call DoPreparePrinting?)
ASSERT(printInfo.m_pPD->m_pd.hDC != NULL);
// gather file to print to if print-to-file selected
CString strOutput;
if (printInfo.m_pPD->m_pd.Flags & PD_PRINTTOFILE && !printInfo.m_bDocObject)
{
// construct CFileDialog for browsing
CString strDef(MAKEINTRESOURCE(AFX_IDS_PRINTDEFAULTEXT));
CString strPrintDef(MAKEINTRESOURCE(AFX_IDS_PRINTDEFAULT));
CString strFilter(MAKEINTRESOURCE(AFX_IDS_PRINTFILTER));
CString strCaption(MAKEINTRESOURCE(AFX_IDS_PRINTCAPTION));
CFileDialog dlg(FALSE, strDef, strPrintDef,
OFN_HIDEREADONLY|OFN_OVERWRITEPROMPT, strFilter, NULL, 0);
dlg.m_ofn.lpstrTitle = strCaption;
if (dlg.DoModal() != IDOK)
return;
// set output device to resulting path name
strOutput = dlg.GetPathName();
}
// set up document info and start the document printing process
CString strTitle;
CDocument* pDoc = GetDocument();
if (pDoc != NULL)
strTitle = pDoc->GetTitle();
else
EnsureParentFrame()->GetWindowText(strTitle);
DOCINFO docInfo;
memset(&docInfo, 0, sizeof(DOCINFO));
docInfo.cbSize = sizeof(DOCINFO);
docInfo.lpszDocName = strTitle;
CString strPortName;
if (strOutput.IsEmpty())
{
docInfo.lpszOutput = NULL;
strPortName = printInfo.m_pPD->GetPortName();
}
else
{
docInfo.lpszOutput = strOutput;
AfxGetFileTitle(strOutput,
strPortName.GetBuffer(_MAX_PATH), _MAX_PATH);
}
// setup the printing DC
CDC dcPrint;
if (!printInfo.m_bDocObject)
{
dcPrint.Attach(printInfo.m_pPD->m_pd.hDC); // attach printer dc
dcPrint.m_bPrinting = TRUE;
}
OnBeginPrinting(&dcPrint, &printInfo);
if (!printInfo.m_bDocObject)
dcPrint.SetAbortProc(_AfxAbortProc);
/**********************************************************************
Problem area.
If the calling thread is not the main thread, the call to AfxGetMainWnd
can return NULL. In this case, hwndTemp->EnableWindow(FALSE) will crash
the application.
**********************************************************************/
// disable main window while printing & init printing status dialog
// Store the Handle of the Window in a temp so that it can be enabled
// once the printing is finished
CWnd * hwndTemp = AfxGetMainWnd(); // <--- CAN RETURN NULL HERE
hwndTemp->EnableWindow(FALSE); // <--- CRASH WILL OCCUR HERE
CPrintingDialog dlgPrintStatus(this);
CString strTemp;
dlgPrintStatus.SetDlgItemText(AFX_IDC_PRINT_DOCNAME, strTitle);
dlgPrintStatus.SetDlgItemText(AFX_IDC_PRINT_PRINTERNAME,
printInfo.m_pPD->GetDeviceName());
dlgPrintStatus.SetDlgItemText(AFX_IDC_PRINT_PORTNAME, strPortName);
dlgPrintStatus.ShowWindow(SW_SHOW);
dlgPrintStatus.UpdateWindow();
// start document printing process
if (!printInfo.m_bDocObject)
{
printInfo.m_nJobNumber = dcPrint.StartDoc(&docInfo);
if (printInfo.m_nJobNumber == SP_ERROR)
{
// enable main window before proceeding
hwndTemp->EnableWindow(TRUE);
// cleanup and show error message
OnEndPrinting(&dcPrint, &printInfo);
dlgPrintStatus.DestroyWindow();
dcPrint.Detach(); // will be cleaned up by CPrintInfo destructor
AfxMessageBox(AFX_IDP_FAILED_TO_START_PRINT);
return;
}
}
// Guarantee values are in the valid range
UINT nEndPage = printInfo.GetToPage();
UINT nStartPage = printInfo.GetFromPage();
if (nEndPage < printInfo.GetMinPage())
nEndPage = printInfo.GetMinPage();
if (nEndPage > printInfo.GetMaxPage())
nEndPage = printInfo.GetMaxPage();
if (nStartPage < printInfo.GetMinPage())
nStartPage = printInfo.GetMinPage();
if (nStartPage > printInfo.GetMaxPage())
nStartPage = printInfo.GetMaxPage();
int nStep = (nEndPage >= nStartPage) ? 1 : -1;
nEndPage = (nEndPage == 0xffff) ? 0xffff : nEndPage + nStep;
VERIFY(strTemp.LoadString(AFX_IDS_PRINTPAGENUM));
// If it's a doc object, we don't loop page-by-page
// because doc objects don't support that kind of levity.
BOOL bError = FALSE;
if (printInfo.m_bDocObject)
{
OnPrepareDC(&dcPrint, &printInfo);
OnPrint(&dcPrint, &printInfo);
}
else
{
// begin page printing loop
for (printInfo.m_nCurPage = nStartPage;
printInfo.m_nCurPage != nEndPage; printInfo.m_nCurPage += nStep)
{
OnPrepareDC(&dcPrint, &printInfo);
// check for end of print
if (!printInfo.m_bContinuePrinting)
break;
// write current page
TCHAR szBuf[80];
ATL_CRT_ERRORCHECK_SPRINTF(_sntprintf_s(szBuf, _countof(szBuf), _countof(szBuf) - 1, strTemp, printInfo.m_nCurPage));
dlgPrintStatus.SetDlgItemText(AFX_IDC_PRINT_PAGENUM, szBuf);
// set up drawing rect to entire page (in logical coordinates)
printInfo.m_rectDraw.SetRect(0, 0,
dcPrint.GetDeviceCaps(HORZRES),
dcPrint.GetDeviceCaps(VERTRES));
dcPrint.DPtoLP(&printInfo.m_rectDraw);
// attempt to start the current page
if (dcPrint.StartPage() < 0)
{
bError = TRUE;
break;
}
// must call OnPrepareDC on newer versions of Windows because
// StartPage now resets the device attributes.
OnPrepareDC(&dcPrint, &printInfo);
ASSERT(printInfo.m_bContinuePrinting);
// page successfully started, so now render the page
OnPrint(&dcPrint, &printInfo);
if ((nStep > 0) && // pages are printed in ascending order
(nEndPage > printInfo.GetMaxPage() + nStep)) // out off pages
{
// OnPrint may have set the last page
// because the end of the document was reached.
// The loop must not continue with the next iteration.
nEndPage = printInfo.GetMaxPage() + nStep;
}
// If the user restarts the job when it's spooling, all
// subsequent calls to EndPage returns < 0. The first time
// GetLastError returns ERROR_PRINT_CANCELLED
if (dcPrint.EndPage() < 0 && (GetLastError()!= ERROR_SUCCESS))
{
HANDLE hPrinter;
if (!OpenPrinter(LPTSTR(printInfo.m_pPD->GetDeviceName().GetBuffer()), &hPrinter, NULL))
{
bError = TRUE;
break;
}
DWORD cBytesNeeded;
if(!GetJob(hPrinter,printInfo.m_nJobNumber,1,NULL,0,&cBytesNeeded))
{
if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
{
bError = TRUE;
break;
}
}
JOB_INFO_1 *pJobInfo;
if((pJobInfo = (JOB_INFO_1 *)malloc(cBytesNeeded))== NULL)
{
bError = TRUE;
break;
}
DWORD cBytesUsed;
BOOL bRet = GetJob(hPrinter,printInfo.m_nJobNumber,1,LPBYTE(pJobInfo),cBytesNeeded,&cBytesUsed);
DWORD dwJobStatus = pJobInfo->Status;
free(pJobInfo);
pJobInfo = NULL;
// if job status is restart, just continue
if(!bRet || !(dwJobStatus & JOB_STATUS_RESTART) )
{
bError = TRUE;
break;
}
}
if(!_AfxAbortProc(dcPrint.m_hDC, 0))
{
bError = TRUE;
break;
}
}
}
// cleanup document printing process
if (!printInfo.m_bDocObject)
{
if (!bError)
dcPrint.EndDoc();
else
dcPrint.AbortDoc();
}
hwndTemp->EnableWindow(); // enable main window
OnEndPrinting(&dcPrint, &printInfo); // clean up after printing
dlgPrintStatus.DestroyWindow();
dcPrint.Detach(); // will be cleaned up by CPrintInfo destructor
}
}
After people told me to shorten the program I did it and here is the shortened version of the program with the same error as stated above.It only appears after a few moments into the program.If i hit continue the program works fine.However see the movement function?It does't work.The sprite refuses to move in any direction.However if i give a very large floating value in the move,then the sprite is displaced from it's position when i start the program and it stays there in that position with no further movement.For example if i write sprite.move(400.f,400.f) the sprite moves from (0,0) to (400,400) and stays there.It doesn't move any more.
Here's the shortened version of the code:
#include"SFML\Graphics.hpp"
#include<iostream>
int main()
{
sf::RenderWindow window(sf::VideoMode(640, 480), "CHECK",sf::Style::Default);
std::cout << "WORKS";
sf::Texture text;
text.loadFromFile("bahamut.png");
sf::Sprite sprite;
sf::Clock frap;
sprite.setTexture(text);
while (window.isOpen())
{
float fps = frap.restart().asSeconds();
sf::Vector2f movements;
if (sf::Keyboard::isKeyPressed(sf::Keyboard::Key::A))
{
movements.y = 0;
movements.x = -1 * fps;
}
else
{if (sf::Keyboard::isKeyPressed(sf::Keyboard::Key::D))
{
movements.y = 0;
movements.x = 1 * fps;
}
else
{ if (sf::Keyboard::isKeyPressed(sf::Keyboard::Key::S))
{
movements.y = 1 * fps;
movements.x = 0;
}
else
{
if (sf::Keyboard::isKeyPressed(sf::Keyboard::Key::W))
{
movements.y = -1 * fps;
movements.x = 0;
}
else
{
movements.x = 0;
movements.y = 0;
}
}
}
}
sprite.move(movements);
window.clear();
window.draw(sprite);
window.display();
}
return 0;
}
I improved upon the code and it still produces the same results and error.
On using the dissassembler i saw the crash occurs at
00B37AEE cmp esi,esp
in window.display().
when i create a function and use it to display the sprite,the movement occurs but witthout the unction nada
Your logic says your movement is 0/0 if W is not pressed. The else of the W pressed block overrides all prior settings. And moving the sprite should happen before you display.
I cannot see a reason for the null pointer exception, but that is what the debugger is for. Next time this happens, debug.
Oh and it's int main(), not void. I know the compiler tolerates this error, but it's still an error and undefined behavior.
So i'm a bit new to C++(4-6 months so far + learning from books(not teachers)) and I understand this problem is most likely a result of my misunderstandings but I still can't figure it out after googling a lot of search terms...
I also tried stackoverflow and read:
Cross-thread operation not valid: Control 'Form1' accessed from a thread other than the thread it was created on
Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on
Best Way to Invoke Any Cross-Threaded Code?
and I attempted to create a solution for this(which you can see below), but I failed to convert the code from c# to c++(I am not a C# user so...)
I can solve it with( from: Crossthread operation not valid... - VB.NET):
listView1->CheckForIllegalCrossThreadCalls = false;
but since it is not good practice, I am looking for an alternative.
when I attempt to call this clr code in my thread:
void CClient::add(){
lvhandle = (HWND)project1::Form1::ClrForm1->listView1->Handle.ToPointer();
/* as you can see here, I tried to figure out how to use MethodInvoker but failed...
if(project1::Form1::ClrForm1->listView1->InvokeRequired){
lvhandle = (HWND)project1::Form1::ClrForm1->listView1->Handle.ToPointer();
//project1::Form1::ClrForm1->listView1->Invoke(gcnew System::Windows::Forms::MethodInvoker(this, &annoyme));
}
else
{
lvhandle = (HWND)project1::Form1::ClrForm1->listView1->Handle.ToPointer();
}*/
item.pszText = LPSTR_TEXTCALLBACK; // Sends an LVN_GETDISPINFO message.
item.mask = LVIF_TEXT | LVIF_IMAGE |LVIF_STATE;
item.stateMask = 0;
item.iSubItem = 0;
item.state = 0;
item.pszText = L"test";
item.lParam = 0;
ListView_InsertItem(lvhandle, &item);
std::string lol = std::to_string(item.iItem);
String^ test;
test = marshal_as<String^>(lol);
project1::Form1::ClrForm1->Text = test;
}
it gives me an exception:
Cross-thread operation not valid: Control 'Form1' accessed from a thread other than the thread it was created on.
ClrForm1 is defined as:
public ref class Form1 : public System::Windows::Forms::Form
{
public:
static Form1^ ClrForm1;
which I create when the entry point is triggered.
int main(array<System::String ^> ^args)
{
// Enabling Windows XP visual effects before any controls are created
Application::EnableVisualStyles();
Application::SetCompatibleTextRenderingDefault(false);
// Create the main window and run it
Form1::ClrForm1 = gcnew Form1();
Application::Run(Form1::ClrForm1);
return 0;
}
I also confirmed the error by doing:
project1::Form1::ClrForm1->Text = "Test!0";
hopefully I detailed this enough to get a response >.<
Firstly, sorry for the poor question title, I didn't know exactly what to put!
So I have an OpenGL application running from a SFML Window context.
I previously posted a question about poor performance, but that issue seems to be solved now.
As you can see on the images I have uploaded, something rather odd is happening. I don't know really how to describe it, but it looks like the right half of the window shouldn't be there!
Anyone any ideas on the problem?
Here is my code:
sf::ContextSettings settings;
settings.depthBits = 32;
settings.stencilBits = 8;
settings.antialiasingLevel=4;
settings.majorVersion = 3;
settings.minorVersion = 0;
sf::Window window(sf::VideoMode(800, 600), "insert title", sf::Style::Default, settings);
window.setVerticalSyncEnabled(true);
bool running = true;
while(running)
{
sf::Event e;
while(window.pollEvent(e))
{
if(e.type == sf::Event::Closed)
{
running = false;
}
if(e.type == sf::Event::Resized)
{
glViewport(0, 0, e.size.width, e.size.height);
gluLookAt(0,0,-1, 0,0,0, 0,1,0);;
}
}
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
glutSolidSphere(1, 12, 12);
window.display();
}
Turns out this is caused by copying and pasting code.
Above the code shown, I had the lines:
sf::ContextSettings settings;
settings.depthBits = 24;
settings.stencilBits = 0;
settings.antialiasingLevel = 0;
settings.majorversion = 3;
settings.minorversion = 2;
The minor version was incorrect. Removing the lines ' settings.majorversion = 3;' and 'settings.minorversion = 2;' fixed the issue!
As an experiment I changed the major to 4. This caused the program to crash all together.
Using Visual studio 2010 and MFC Doc/View Applications I want my SDI application to start up completely hidden, and after sometime or with receiving some message from tray icon it shows the mainframe, view and so on. I change the line m_pMainWnd->ShowWindow(SW_NORMAL); to m_pMainWnd->ShowWindow(SW_HIDE); in BOOL CMyApp::InitInstance() but the main frame just flickers after executing the application and then goes hiiden what should I do inorder to avoid this problem and keep the showing capability of main frame when ever I want.
Here is the solution for SDI/MDI app: The new MFC (with VC2010) overrides the m_nCmdShow value with a setting stored in the system registry. To change this behaviour, simply override the LoadWindowPlacement virtual function in the application class.
BOOL CAdVisuoApp::LoadWindowPlacement(CRect& rectNormalPosition, int& nFflags, int& nShowCmd)
{
BOOL b = CWinAppEx::LoadWindowPlacement(rectNormalPosition, nFflags, nShowCmd);
nShowCmd = SW_HIDE;
return b;
}
Normally if you have VC2005 or earlier the following will do:
// Parse command line for standard shell commands, DDE, file open
CCommandLineInfo cmdInfo;
ParseCommandLine(cmdInfo);
m_nCmdShow = SW_HIDE;
// Dispatch commands specified on the command line. Will return FALSE if
// app was launched with /RegServer, /Register, /Unregserver or /Unregister.
if (!ProcessShellCommand(cmdInfo))
return FALSE;
// The one and only window has been initialized, so show and update it
m_pMainWnd->ShowWindow( m_nCmdShow);
m_pMainWnd->UpdateWindow();
Note that m_nCmdShow should be set to SW_HIDE before ProcessShallCommand for the flicker not to occur.
It looks like there might be a bug in VC2010 though. Since I have done this before it intrigued me and tried a fresh VC2010 project but it was not working. I noticed the problem was deep in the following MFC function.
BOOL CFrameWnd::LoadFrame(UINT nIDResource, DWORD dwDefaultStyle,
CWnd* pParentWnd, CCreateContext* pContext)
{
// only do this once
ASSERT_VALID_IDR(nIDResource);
ASSERT(m_nIDHelp == 0 || m_nIDHelp == nIDResource);
m_nIDHelp = nIDResource; // ID for help context (+HID_BASE_RESOURCE)
CString strFullString;
if (strFullString.LoadString(nIDResource))
AfxExtractSubString(m_strTitle, strFullString, 0); // first sub-string
VERIFY(AfxDeferRegisterClass(AFX_WNDFRAMEORVIEW_REG));
// attempt to create the window
LPCTSTR lpszClass = GetIconWndClass(dwDefaultStyle, nIDResource);
CString strTitle = m_strTitle;
if (!Create(lpszClass, strTitle, dwDefaultStyle, rectDefault,
pParentWnd, ATL_MAKEINTRESOURCE(nIDResource), 0L, pContext))
{
return FALSE; // will self destruct on failure normally
}
// save the default menu handle
ASSERT(m_hWnd != NULL);
m_hMenuDefault = m_dwMenuBarState == AFX_MBS_VISIBLE ? ::GetMenu(m_hWnd) : m_hMenu;
// load accelerator resource
LoadAccelTable(ATL_MAKEINTRESOURCE(nIDResource));
if (pContext == NULL) // send initial update
SendMessageToDescendants(WM_INITIALUPDATE, 0, 0, TRUE, TRUE);
return TRUE;
}
m_nCmdShow is still SW_HIDE when this function executes but it changes to SW_SHOWNORMAL when if (!Create(lpszClass... line executes. I don't know why this happens in VC2010 project only, sounds like a bug to me.
My sample project was SDI.
This comes from a dialog based application but you should be able to convert it to a Doc/View app as well. You need to handle the OnWindowPosChanging event. The key line is the the one inside the if statement. This allows my application to start completely hidden from view.
void CIPViewerDlg::OnWindowPosChanging( WINDOWPOS FAR* lpWindowPosition )
{
if( !m_bVisible )
{
lpWindowPosition->flags &= ~SWP_SHOWWINDOW;
}
CDialog::OnWindowPosChanging( lpWindowPosition );
}
Make sure that you are correctly turning off the WS_VISIBLE bit in CMainFrame::PreCreateWindow(CREATESTRUCT& cs). Something like this should worK:
cs.style &= ~WS_VISIBLE;
We had simply been negating the bit instead of turning it off, and we got away with it in VS 6.0 because this function was called only once. It is called twice in newer versions of Visual Studio, so in the second call we were flipping it right back on again. :-O
I tried all for Visual Studio 2010 and finished up with:
class CMainFrame : public CFrameWndEx
{
// ...
// Attributes
public:
BOOL m_bForceHidden;
// ...
// Overrides
public:
virtual void ActivateFrame(int nCmdShow = -1);
//...
};
CMainFrame::CMainFrame() : m_bForceHidden(TRUE)
{
// ...
}
void CMainFrame::ActivateFrame(int nCmdShow)
{
if(m_bForceHidden)
{
nCmdShow = SW_HIDE;
m_bForceHidden = FALSE;
}
CFrameWndEx::ActivateFrame(nCmdShow);
}
Other tricks did not work for me.
Found solution at:
http://forums.codeguru.com/showthread.php?478882-RESOLVED-Can-a-Doc-view-be-hidden-at-startup
I found in VS2017 (using BCGControlBar Pro which is what MFC Feature Pack was based on) that you have to handle things in two places:
BOOL CMainFrame::LoadFrame(UINT nIDResource, DWORD dwDefaultStyle, CWnd* pParentWnd, CCreateContext* pContext)
{
if (!__super::LoadFrame(nIDResource, dwDefaultStyle, pParentWnd, pContext))
{
return FALSE;
}
// undo what __super::LoadFrame() does where it will set it to SW_NORMAL if not SW_MAXIMIZED
AfxGetApp()->m_nCmdShow = SW_HIDE;
}
BOOL CTheApp::LoadWindowPlacement(CRect& rectNormalPosition, int& nFflags, int& nShowCmd)
{
BOOL b = __super::LoadWindowPlacement(rectNormalPosition, nFflags, nShowCmd);
nShowCmd = SW_HIDE;
return b;
}