I am creating an MFC application which will be launched on click on Explorer Context (Rightclick) menu.
But I need to launch only single instance of the application. For that I have to use FindWindow and AfxRegisterClass
I tried to register the class in my MFC app as below:
BOOL CNDSClientDlg::InitInstance()
{
//Register Window Updated on 16th Nov 2010, #Subhen
// Register our unique class name that we wish to use
WNDCLASS wndcls;
memset(&wndcls, 0, sizeof(WNDCLASS));
//Class name for using FindWindow later
wndcls.lpszClassName = _T("NDSApp");
// Register new class and exit if it fails
if(!AfxRegisterClass(&wndcls)) // [C]
{
return FALSE;
}
}
and called the method in the constructor of the MFC class. I verified that the class is being registered while I am starting the application.
Now in my shell Extension I am trying to find the Class registered in my MFC as below:
CWnd *pWndPrev = NULL;
pWndPrev = CWnd::FindWindow(_T("NDSApp"),NULL);
if(pWndPrev != NULL)
pWndPrev->BringWindowToTop();
But I am not able to get the CWnd to Window. Not able to figure it out. Please let me know if I am missing something or doing something wrong.
FindWindow finds window instances not window classes. In your app which registers the class you need to actually create a window so that the extension can find that window.
(Finding the window by class name is fine; the problem is you haven't actually created anything to find.)
Also, I suspect if you try to create a window based on the window-class you've registered it will fail because you've left most of the WNDCLASS structure null. See the example you linked to for better default values. (e.g. You must provide a wndproc and hinstance.)
Related
I am really struggling how to make a window with three selections of options. I currently have a setup that uses a CFileDialog object and have successfully implemented two dropdown menus and multiple check items.
What I want is to implement a pop up window that has the two drop down menus and the check boxes. If a certain item is selected in one of the dropdown menus then the file dialog is opened.
Currently I am trying to make a CWnd object and try to write code for it there.
CWnd myWindow;
BOOL VALUE = myWindow.Create(_T("DesktopApp"), _T("test"), WS_VISIBLE | WS_BORDER | WS_CAPTION,
RECT{ 100,100,400,400 },
myWindow.GetDesktopWindow(), 12);
myWindow.ShowWindow(SW_SHOWNORMAL);
if (VALUE == FALSE) {
return 0;
}
Every time I run this, it prematurely returns (VALUE == FALSE). Did I do something wrong? Is there a simpler way to create a window?
The first argument to CWnd::Create is the window class name. A class with the requested name must have been registered before it can be created.
It is common to register an application local class for the application's main window. MFC provides a convenient wrapper function (AfxRegisterWndClass) to register a window class.
I am new to MFC and have built an "outlook" style MFC app using the wizard. I've extended the CMFCShellTreetCtrl using CMyShellTreeCtrl and had data member variables and all was working fine. Now I want to move the data over to the CDocument class. Since there is several accesses to the data as each item is clicked or enumerated, I thought I would create a member variable m_pDoc to access the public variables in the CDocument. The problem I'm having, I can't find where to get the CDocument as it appears it's not setup when the trees OnCreate is called. That is in OnCreate
CWnd* pWndMain = AfxGetMainWnd();
ASSERT(pWndMain);
ASSERT(pWndMain->IsKindOf(RUNTIME_CLASS(CFrameWnd)) && !pWndMain->IsKindOf(RUNTIME_CLASS(CMDIFrameWnd))); // Not an SDI app.
m_pDoc = (CMyDoc*) ((CFrameWnd*)pWndMain)->GetActiveDocument();
returns NULL in m_pDoc and if I tried in an AfterCreate() (which is called after CreateOutlookBar) it's too late as m_pDoc is already being used and get a crash.
// Create and setup "Outlook" navigation bar:
if (!CreateOutlookBar(m_wndNavigationBar, ID_VIEW_NAVIGATION, m_wndTree, m_wndCalendar, 250))
{
TRACE0("Failed to create navigation pane\n");
return -1; // fail to create
}
m_wndTree.AfterCreate();
Any Ideas?
TIA!!
I came up with the following but I'm not sure if this is the proper way. Again, I'm new to MFC (I always have used Win32 directly). This works so it's AN answer, but is it THE correct answer?
POSITION docpos = AfxGetApp()->GetFirstDocTemplatePosition();
CDocTemplate *doctemplate = AfxGetApp()->GetNextDocTemplate(docpos);
docpos=doctemplate->GetFirstDocPosition();
m_pDoc = (CMyDoc*)doctemplate->GetNextDoc(docpos);
ASSERT(m_pDoc);
ASSERT(m_pDoc->IsKindOf(RUNTIME_CLASS(CMyDoc)));
TIA!!
I just tried to setup a small win32 project, and was just about to create a window.
I created a dialog in the resource designer and set up this class for my window:
#pragma once
#include "stdafx.h"
class TTTMainDialog : public CWindowImpl<TTTMainDialog>
{
public:
DECLARE_WND_CLASS(_T("TTTDlg"))
enum { IDD = IDD_TTT_DIALOG };
BEGIN_MSG_MAP_EX(MusicPlayerDialog)
MSG_WM_INITDIALOG(OnInitDialog);
MSG_WM_CLOSE(OnClose);
MSG_WM_DESTROY(OnDestroy);
END_MSG_MAP()
TTTMainDialog();
~TTTMainDialog();
private:
const BOOL OnInitDialog(const CWindow wndFocus, const LPARAM lInitParam);
void OnClose();
void OnDestroy();
};
As you can see, I added the window class declaration, I inherited CWindowImpl, I registered the dialog. I don't think I forgot something here.
In the class which is supposed to create the dialog, I tried to create it like this:
TTTMainDialog myDialog;
HWND handle = myDialog.Create(NULL);
myDialog.ShowWindow(nCmdShow);
However, the Create method does return NULL all the time. I checked the error code with GetLastError(), and it turns out i am getting error code 1406, or "ERROR_TLW_WITH_WSCHILD".
The msdn documentation says the following about this error:
"Cannot create a top-level child window."
I tried to google up on this, but there is not much to find.
If I had to take a guess I would say the problem is caused by some window class name details, but i'm really not sure.
Any advice?
You are trying to build a window class from wrong pieces.
The error is pretty descriptive: you are trying to create a parentless window with a WS_CHILD style and this does not work out.
You get the child style from default template parameter: CWindowImpl -> CWindowImplBaseT -> TWinTraits -> CControlWinTraits. CControlWinTraits is supposed for use with child control windows.
If you are going to use a dialog template (IDD_TTT_DIALOG) then the proper base class is CDialogImpl, which is already prepared to use proper window styles. Also, it has what it takes to create both modal and modeless dialogs. The latter act more like windows and are non-blocking but in the same time take dialog template resource with predefined controls.
Small example for CDialogImpl use
Or, another one
I have followed this link to get the window handle of a ActiveX control
Sample Code from microsoft's site
// The following code should return the actual parent window of the ActiveX control.
HWND CMyOleControl::GetActualParent()
{
HWND hwndParent = 0;
// Get the window associated with the in-place site object,
// which is connected to this ActiveX control.
if (m_pInPlaceSite != NULL)
m_pInPlaceSite->GetWindow(&hwndParent);
return hwndParent; // Return the in-place site window handle.
}
But in my case I keep finding that "m_pInPlaceSite" is always NULL. I'm trying to run this code in my controls FinalConstruct. Is there something else I need to implement for the m_pInPlaceSite to be given a value? Or do I need to Query to get the value.
Thanks
FinalConstruct is way too early. In FinalConstruct your class is just being created and is not yet initialized. There is no "in place" site, there is no yet site at all.
Your control will be called by its owner, it will be given its site, then activated - only then you will possibly have m_pInPlaceSite available.
To preface we have a strange requirement that all dialogs must be modeless for an MFC application. There is a particular dialog using region drawing and some custom controls to select dates and times for viewing past and future data per view. I need to be able to close this window when it loses focus, the main app gets a system command, etc.
I figured the easiest way to do this would be to register the class like so:
// for CWnd::FindWindow
WNDCLASS wndcls;
SecureZeroMemory(&wndcls, sizeof(WNDCLASS));
wndcls.lpszClassName = L"CTransactionDialog";
wndcls.style = CS_HREDRAW | CS_VREDRAW;
wndcls.lpfnWndProc = AfxWndProc;
wndcls.cbClsExtra = wndcls.cbWndExtra = 0;
wndcls.hInstance = AfxGetInstanceHandle();
wndcls.hIcon = NULL;
#ifndef _WIN32_WCE_NO_CURSOR
wndcls.hCursor = AfxGetApp()->LoadStandardCursor(IDC_ARROW);
#else
wndcls.hCursor = 0;
#endif
wndcls.hbrBackground = (HBRUSH) (COLOR_BACKGROUND + 1);
wndcls.lpszMenuName = NULL;
BOOL retVal = AfxRegisterClass(&wndcls);
if (!retVal)
AfxMessageBox(L"AfxRegisterClass(CTransactionDialog) Failed");
Then later in response to various event handlers and messages where I would want these modeless window or windows to be closed to do something simple like this:
CWnd* pFound = NULL;
while ((pFound = CWnd::FindWindow(L"CTransactionDialog", NULL)) != NULL)
pFound->DestroyWindow();
However despite the registration of the class succeeding and looking at GetRuntimeClass of the dialog in question in debug and seeing that is matches up as expected the FindWindow never seems to find or close these modeless dialogs as expected.
What am I doing wrong or is there a better way to go about this?
Update: This is how the dialog is created via a static method on the dialog class. The dialog resource for the id specified in create has the Popup property set which should resolve to WS_POPUP style under the MFC covers. The dialog shouldn't and doesn't have a parent as far as I knew.
CTransactionDialog* CTransactionDialog::ShowTransactionDialog(const CRect& crCtrlToFloatAbove, UINT dialogID, Itime defaultTime, Itime initialTime)
{
CTransactionDialog* pCTDialog = new CTransactionDialog(crCtrlToFloatAbove, dialogID, defaultTime, initialTime);
pCTDialog->Create(CTransactionDialog::IDD);
pCTDialog->ShowWindow(SW_SHOW);
return pCTDialog;
}
Update: Doh! FindWindowEx isn't finding anything either.
CWnd::FindWindowEx(AfxGetMainWnd()->GetSafeHwnd(), NULL, L"CTransactionDialog", NULL);
However I have a new plan. I'm just going to make my own window message and handle it on the main frame. I think I can get away with passing a pointer to the dialog as the lParam of the message and then casting it to a CWnd* then calling DestroyWindow. It will work for most cases in a very round about way. I may run into trouble with minimizing and maximizing of the main frame window for dialogs that nothing is holding a pointer too but we'll see.
FindWindow doesn't work with child windows. To find a child window, you can use FindWindowEx, passing the HWND of the parent window as the first parameter.
Class name denotes NOT the c++ class name - it denotes the window class name. This name was used to register the window by the OS and has nothing to do with the c++ class.
May MSDN enlight you...
CWnd::FindWindow does not search child windows.
Is it possible that the mode less window that you are creating has a parent set and that is the reason why FindWindow doesn't find it ?
Below is the simplest and cleanest solution I could come up with:
BOOL CTransactionDialog::OnNcActivate(BOOL bActive)
{
if (!bActive)
PostMessage(WM_CLOSE);
return CDialog::OnNcActivate(bActive);
}
Not 100% sure about this but I think you need to set your class name in the resource file. You are defining a windows class and creating a dialog class but you aren't linking them. Setting a class name in the WNDCLASS struct won't help unless you actually have a way of linking it to the dialog. If you use the resource file and define the dialog, and class name in there then it should work.