C / C++ / MFC

31-Jul-02 14:07

Hi.

I have a MFC application that creates a lot of child windows. I want to get a pointer to CMainFrame from my child windows during their OnCreate handlers. Im doing it like this;

CMainFrame * pMain=(CMainFrame *)AfxGetMainWnd();

The problem is that it only works AFTER all initialization is done, for example when i trigger a handler for a window click.

I REALLY need to get a pointer to CMainFrame during the creating procedure but i cant find a place in CMainframe to insert my child windows "Create" function. Ive tried it on "OnCreateClient" and in "OnCreate", even after the CFrameWnd::OnCreate(...).

Thank you in advance

PJ Arends31-Jul-02 14:48

31-Jul-02 14:48

use the hwndParent parameter of the supplied CREATESTRUCT structure.

CPUA 0x5041

Sonork 100.11743 Chicken Little

"So it can now be written in stone as a testament to humanities achievments "PJ did Pi at CP"." Colin Davies

Within you lies the power for good - Use it!

Miguel Lopes1-Aug-02 3:28

1-Aug-02 3:28

The hwndParent parameter isnt pointing to CMainFrame. This is a child CWnd fomr a child window from a CMainFrame's child window. So, its CMainFrame great grandaugther.

Also, is there a way i can declare a global variable pointing to CMainFrame?

PJ Arends1-Aug-02 7:07

1-Aug-02 7:07

You should be abl to set a global variable to a valid CMainFrame in your CMainFrame::OnCreate() member function as long as it is after the call to the base class's OnCreate() function.

I have not tried this, but here goes:

int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
    if (CMDIFrameWnd::OnCreate(lpCreateStruct) == -1)
        return -1;

    g_MyGlobalMainFrame = this;

...

Miguel Lopes1-Aug-02 8:48

1-Aug-02 8:48

Im having no problem in creating a global variable. The problem is that it must be declared in a file that every other header can include it. If my child window is declared as an include in CMainframe, and the global is also in CMainframe, i cant include CMainframe in the child, cause it gives me a Linking error cause im going recursive in includes.

So, can i just create a separate file (or use StdAfx?), create the global there, initialize it within CMainframe and include it in each class i want?

PJ Arends1-Aug-02 9:14

1-Aug-02 9:14

Do not declare global variables in any header files. Declare them in one, and only one cpp file, and any cpp file that needs to use them imports it using the extern keyword

// In MainFrame.cpp
...
#include "MainFrm.h"

CMainFrame *g_MyGlobalMainFrame = NULL;
...

int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
    if (CMDIFrameWnd::OnCreate(lpCreateStruct) == -1)
        return -1;

    g_MyGlobalMainFrame = this;
...

// In any other cpp file that needs access to g_MyGlobalMainFrame
#include "MainFrm.h"
extern CMainFrame *g_MyGlobalMainFrame

...

Miguel Lopes2-Aug-02 0:57

2-Aug-02 0:57

Thanks!!

'Notify'-> WS_NOTIFY?!?

Selevercin31-Jul-02 14:03

Selevercin

31-Jul-02 14:03

Hi,

I have made some bitmaps dynamically. I wish to add the notify ability to them. I tried WS_NOTIFY, but it told me that it doesn't exist. How do I give the notify ability to my bitmaps?

Thanks,

~ Selevercin

If you have a problem with my spelling, just remember that's not my fault. I [as well as everyone
else who learned to spell after 1976] blame it on
Robert A. Kolpek for U.S. Patent 4,136,395.

Marc Clifton31-Jul-02 14:29

Marc Clifton

31-Jul-02 14:29

There's probably a dozen different ways to do this. I create dynamic bitmaps by deriving a custom bitmap control from CWnd and override the OnLButtonDown message. But your implementation might be different.

Marc

Selevercin31-Jul-02 14:44

Selevercin

31-Jul-02 14:44

Sorry, but how would you derive a custom bitmap control from CWnd? Is there a tutorial for this?

~ Selevercin

If you have a problem with my spelling, just remember that's not my fault. I [as well as everyone
else who learned to spell after 1976] blame it on
Robert A. Kolpek for U.S. Patent 4,136,395.

Marc Clifton31-Jul-02 16:29

Marc Clifton

31-Jul-02 16:29

I usually display bitmaps that have been loaded from a file, not a resource. Here's a code snippet:

<br />
BitmapControl::BitmapControl(CWnd* parent) : CWnd(), hInternalImage(0)<br />
{<br />
}<br />
<br />
void BitmapControl::Create(const CWnd* v, const CRect& r, const int id)<br />
{<br />
	HCURSOR cursor=AfxGetApp()->LoadCursor(IDC_ARROW);<br />
	const char* className=AfxRegisterWndClass(0, cursor, (HBRUSH) GetStockObject(WHITE_BRUSH));<br />
	CWnd::CreateEx(0, className, "", WS_CHILD | WS_VISIBLE, r, (CWnd*)v, id);<br />
}<br />
<br />
void BitmapControl::LoadImage(const AutoString& imageFile)<br />
{<br />
	if (hInternalImage)<br />
	{<br />
		DeleteObject(hInternalImage);<br />
	}<br />
	hInternalImage=::LoadImage(0, imageFile, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE | LR_LOADMAP3DCOLORS | LR_LOADTRANSPARENT);<br />
	InvalidateRect(NULL);<br />
}<br />
<br />
void BitmapControl::OnLButtonDown(UINT nFlags, CPoint point)<br />
{<br />
	int x=point.x;<br />
	int y=point.y;<br />
	// ... do something about the click<br />
	CWnd::OnLButtonDown(nFlags, point);<br />
}<br />
<br />
void BitmapControl::OnPaint(void)<br />
{<br />
	HANDLE h=hInternalImage;<br />
<br />
	CRect r=GetClientRect();<br />
	PAINTSTRUCT ps;<br />
	CDC* dc=BeginPaint(&ps);<br />
	if (h)<br />
	{<br />
		CDC src;<br />
		src.CreateCompatibleDC(NULL);<br />
		CBitmap* bitmap=CBitmap().FromHandle((HBITMAP)h);<br />
		BITMAP bm;<br />
		bitmap->GetBitmap(&bm);<br />
		src.SelectObject(bitmap);<br />
		int destW=r.right-r.left;<br />
		int destH=r.bottom-r.top;<br />
		int srcW=bm.bmWidth;<br />
		int srcH=bm.bmHeight;<br />
		dc->FillSolidRect(0, 0, destW, destH, COLORREF(0x00FFFFFF));<br />
		dc->BitBlt((destW-srcW)/2, (destH-srcH)/2, r.right-r.left, r.bottom-r.top, &src, 0, 0, SRCCOPY);<br />
		EndPaint(&ps);<br />
	}<br />
	else<br />
	{<br />
		int destW=r.right-r.left;<br />
		int destH=r.bottom-r.top;<br />
		dc->FillSolidRect(0, 0, destW, destH, COLORREF(0x00FFFFFF));<br />
		EndPaint(&ps);<br />
	}<br />
	CWnd::OnPaint();<br />
}<br />
<br />

---
Marc

PJ Arends31-Jul-02 14:44

31-Jul-02 14:44

Use a static control to display the bitmap (using CStatic::SetBitmap()), and set the static control's SS_NOTIFY style

Selevercin31-Jul-02 14:54

Selevercin

31-Jul-02 14:54

WOW!!! Thank you SO much, PJ Arends! You solved a BIG problem that I've been ignoring for the past month (I haven't programmed since I got SO frustrated with my problem).

This is what the problem was. I created a bunch of dynamic bitmaps for a card game. I wanted to be able to click them, so origionally, I used the OnLeftButtonDwn() with CPoint for every position on the card (there about 30ish cards). Needless to say, after the 3rd card I realized it would take an army of programmers to finish it.

Finally, I came up with the idea of making a bunch of static bitmaps, change their resource number to the ID numbers of the bitmaps, add a BN_CLICKED message for my static bitmaps, and finally delete the static bitmaps. My plan didn't appear to be working, until today I realized my whole problem was that I needed a notify message.

Thanks again! (If you want to see the card game when I'm finished let me know)

~ Selevercin

If you have a problem with my spelling, just remember that's not my fault. I [as well as everyone
else who learned to spell after 1976] blame it on
Robert A. Kolpek for U.S. Patent 4,136,395.

PJ Arends31-Jul-02 15:09

Beginner's one: Minimizing wnd message...

31-Jul-02 15:09

Selevercin wrote:
Thanks again!

No prob Big Grin | :-D

Selevercin wrote:
If you want to see the card game when I'm finished let me know

Sounds like an article;);)

BlackSmith31-Jul-02 13:48

BlackSmith

31-Jul-02 13:48

High

What message is sent when a window is minimizing/minimized?
I want to create some tool (don't ask me Y...) which can determine if a window
is minimizing. I'm sure that if I've a CWnd derived obj, some message is sent
to it when some other window is minimized/ing. if this messge handler contain
some info about the window that's min's it will be mu(n)ch better Big Grin | :-D

Hope you can figure what I'm saying (cause' I'm not so sure I do...).

Good night everybooty, I've left the building.

--BlackSmith--

"With the help of all mighty", 2001, Me.

Re: Beginner's one: Minimizing wnd message...

PJ Arends31-Jul-02 14:39