C / C++ / MFC

8-Nov-01 22:57

Hi,

Has anyone had this problem before:

If I click in the CListCtrl in report view and ALT+TAB toggles to another program (which completly hides the control) and then toggles back to the app with the CListCtrl, the control disappears.

However it works if I don't click the CListCtrl and performs the some thing as above.

I've included the CListCtrl (report view) on a dialog which in turn is on a tab page.

Any ideas anyone?

/Tommy

Tomasz Sowinski8-Nov-01 23:30

8-Nov-01 23:30

I've included the CListCtrl (report view) on a dialog which in turn is on a tab page.

But it isn't a propertypage/sheet, right? Probably you have a problem with z-order. Try to handle WM_ACTIVATEAPP and bring contents of tab to front.

Tomasz Sowinski -- http://www.shooltz.com

Tommy H D Svensson9-Nov-01 1:13

9-Nov-01 1:13

Yes you're right, no propertypage/sheet.

But I tried to loacate which window is on top with GetTopWindow and from the result the CListCtrl should be on top, but maybe the result is incorrect when I'm in debug mode (see comments below).

See if we can narrow the problem down. It works like this:

I have my CTabStrl in the var m_TabCtrl.

I've created several dialogs each of which is "activated" like this when I click on a tab:

void CSystemInfoDlg::OnSelchangeTab1(NMHDR* pNMHDR, LRESULT* pResult)
{
ActivateTab(m_TabCtrl.GetCurSel());
*pResult = 0;
}

void CSystemInfoDlg::ActivateTab(int nTab)
{
if (pCurDlg)
{
pCurDlg->ShowWindow(SW_HIDE);
}

pCurDlg = pDlgs[nTab];
pCurDlg->ShowWindow(SW_SHOW);
}

When I try to debug it works?!!? I'm clicking on a CListCtrl which is on every pDlgs and after toggling away the app and toggling it back and then doing something to reach a breakpoint and then continue with F5, the CListCtrl shows up again... But that doesn't happen if I don't debug...

Any ideas?

/T

Tomasz Sowinski9-Nov-01 1:27

9-Nov-01 1:27

I've dusted off one very old project I was involved in. There was similar problem - there was a CListCltr directly on CDialog (no list controls) which was disappearing after Alt+Tab. Adding a WM_ACTIVATEAPP handler solved the problem:

void CSomeDlg::OnActivate(UINT nState, CWnd* pWndOther, BOOL bMinimized) 
{
	CDialog::OnActivate(nState, pWndOther, bMinimized);
	if (nState == WA_ACTIVE)
	{
		m_lst.BringWindowToTop();
	}
}

Tomasz Sowinski -- http://www.shooltz.com

Tommy H D Svensson9-Nov-01 1:37

9-Nov-01 1:37

Hmm, I did like this

- Added ON_WM_ACTIVATEAPP in the message map
- Added the OnActivate method to one of the dialogs
- Added a breakpoint at CDialog::OnActivate(...)

but the breakpoint was never found... Did I do something wrong?

/T

Tomasz Sowinski9-Nov-01 1:57

9-Nov-01 1:57

Did you use Alt+Tab when dialog is open?

Tomasz Sowinski -- http://www.shooltz.com

Tommy H D Svensson9-Nov-01 2:22

9-Nov-01 2:22

[Tomasz, please send me a mail instead because I have to poll for new messages... don't know why but I'm not getting any replies in my mailbox.]

Yes, I clicked the tab -> the dialog with the CListCtrl showed up -> I clicked the CListCtrl somewhere -> tabbed away -> tabbed back -> the CListCtrl is gone.

Now I wanted to check which window was on the top of the z-order by using GetTopWindow(). And I did this by reacting to a click on the dlg, not the CListCtrl, AFTER I had toggled back the app (that is when the CListCtrl had disappeared). So I set a breakpoint in the OnLButtonDown handler to check the handles for the dialog and the ctrl. If the CListCtrl is beneath the dialog then the handles of ctrl and top should NOT be equal. At least that's what I thought...

void CsomeDlg::OnLButtonDown(UINT nFlags, CPoint point)
{
CWnd* ctrl = &m_List;
CWnd* dlg = this;
CWnd* top = GetTopWindow();
}

The handles were all different... but that maybe depends on something else... what wa important here was that when I pressed F5 to continue running the app, the CListCtrl showed up again...?!?!

Tomasz Sowinski9-Nov-01 2:40

9-Nov-01 2:40

Check top->GetDlgCtrlID(). It may give you an idea which window is on top,

Tomasz Sowinski -- http://www.shooltz.com

Tommy H D Svensson9-Nov-01 2:59

9-Nov-01 2:59

Yes, it did! It says the dialog is on top. But, from what I know the CListCtrl is a child window of the dialog and therefore the ctrl should be visible as well... or is it not a child window? Do I have to make an explicit call to m_List.Create from the dlg to make it a child? I always thought that I if I drag a ctrl on a dialog, the explicit creation of the ctrl is not needed since the wizard adds a variable for me and updates the DDX stuff...

It's like the ctrl doesn't update its painting...

Well, I'll send you a sample project. Smile | :)

Tomasz Sowinski9-Nov-01 3:07

9-Nov-01 3:07

I've just realized that you're clicking on a dialog surface - it's no surprise that it becomes a top window.

Anyway, I have no idea why aren't you getting a WM_ACTIVATEAPP message. Can you check with Spy++, if your app gets one when you Alt-Tab?

BTW: you don't need to call Create on m_List. It's created by Windows during the call to DialogBox or CreateDialog.

Tomasz Sowinski -- http://www.shooltz.com

Tommy H D Svensson9-Nov-01 5:58

9-Nov-01 5:58

Hi Tomasz,

I just got a solution to the problem with a little help from another Codeproject dude [thx Joel!].

The thing is that whenever a WM_ERASEBKGND is received by a CTabCtrl, all window children of CTabCtrl that are CListCtrls don't get properly repainted if they have been "focused".

The fix is just to call RedrawWindow on the CListCtrl when ever appropriate.

As always Tomasz, thx for your superb help and 'be there'-frequency!

/Tommy

Tommy H D Svensson9-Nov-01 1:23

Removing Menu from Mainframe

9-Nov-01 1:23

Also, I must add, when the CListCtrl is gone I can activate parts of it by clicking "on it"... It lights up row wise but the entire CListCtrl border doesn't show... Somehow it reacts to my mouse clicks. Is it then possible it is hidden by a window with higher z since it responds to user actions?

[James Pullicino]8-Nov-01 21:51

[James Pullicino]

8-Nov-01 21:51

Hi all,

I would like to remove the menu from my mainframe in MFC. Does anybody know how?

Thanks,

James

(2b || !2b)

Re: Removing Menu from Mainframe

Tomasz Sowinski8-Nov-01 23:13

Source Code of a Simple Calculator

8-Nov-01 23:13

CWnd::SetMenu(NULL) removes the menu. If you have MDI app, you'll also have to override CFrameWnd::OnUpdateFrameMenu.

Tomasz Sowinski -- http://www.shooltz.com

GDI+

AJ1238-Nov-01 21:37

AJ123

8-Nov-01 21:37

Hi,

I am using GDI+ to convert a batch of TIFFS to JPEGS - i was just wondering how i can resize a image object and then save it out. Does it have to go via a 'graphics' object.

Because I can't see a convenient way to save the graphics object out to a jpeg after i have done my drawimage.

Cheers
Richard

Re: GDI+

Christian Graus8-Nov-01 22:04

Christian Graus

8-Nov-01 22:04

I answered this already. You build the graphics object using the Bitmap, then resize it and the bitmap will be resized.

Christian

After all, there's nothing wrong with an elite as long as I'm allowed to be part of it!! - Mike Burston Oct 23, 2001

Re: GDI+

AJ1239-Nov-01 3:07

AJ123

9-Nov-01 3:07

Thanks, did see your reply , though it didn't really help me much, i tend to find message that are posted a few pages back tend to get ignored . Had a look at your tutorial to.

I recognise i have to use the Graphics class, i wrote the following code to try and manipulate an image from a file, as a start basis.

//Source Image
Image* image = new Image(L"c:\\test.bmp");

Graphics* imageGraphics = Graphics::FromImage(image);

Pen* blackpen= new Pen(Color(0, 0, 0, 0), 10);

Point point1(0, 0);
Point point2(100, 300);

// Draw A line.
imageGraphics->DrawLine(blackpen, point1, point2);

imageGraphics->Flush(FlushIntentionSync);

// Get the CLSID of the JPG
if (GetEncoderClsid(L"image/jpeg", &encoderClsid) == -1)
MessageBox("No suitable encoder");

MessageBox("About to save");
stat = image->Save(L"c:\\conv.jpg", &encoderClsid, NULL);
MessageBox("Done");

if(stat != Ok)
{
//Have A Failure Log
char err[255];
wsprintf(err,"%d", stat);

MessageBox("Failure: stat = ");
}

delete blackpen;
delete imageGraphics;
delete image;

GdiplusShutdown(gdiplusToken);

Thanks Again, must start and try and hekp out on the forum myself!

Rich

Re: GDI+

AJ12310-Nov-01 4:28

AJ123

10-Nov-01 4:28

The reason the above code didn't draw a line on the saved image, was because of the encoder, if i was drawing on a jpeg and saving to a jpeg. It would of.

As for my image conversion routine. I ended up having to use a 'Bitmap' object in order to create a new image, this was done through passing the contructor a HBITMAP. Couldn't see how you could create a new image in GDI+ anyother way???

Cheers
Rich

8-Nov-01 18:51

Hi,
I am engaged in a project ,now I require some source
code of a simple( not scientific) calcutor to speed up
my process in this project.Who can help me?
You can send it to my Email ,fengrux@hotmail.com

regards.

Jon Sagara8-Nov-01 21:06

Jon Sagara

8-Nov-01 21:06

Here you go:

#include <iostream.h>

int main()
{
    int a = 1;
    int b = 1;
    int c = a + b;

    cout << "Non-scientific calculation: " << c << endl;

    return 0;
}

I know. Terribly lame joke. It's late and I'm delirious. I need to get some sleep. Good luck with your project.

Jon Sagara

"After all is said and done, usually more is said than done." -- Unknown

Nish Nishant8-Nov-01 21:23

Nish Nishant

8-Nov-01 21:23

LOL

Sonork ID 100.9786 voidmain

www.busterboy.org

Nish is a BIG fan of Goran Ivanisevic

Christian Graus8-Nov-01 22:06

Christian Graus

8-Nov-01 22:06

Bwahahahahaa - if you can't write a calculator, I presume you are writing a hello world and want it to calculate how many characters it has.

This is an interesting take on the 'please do my homework, I am too lazy and stupid' theme. Thanks for sharing it. Now go and do your own homework.

Christian

After all, there's nothing wrong with an elite as long as I'm allowed to be part of it!! - Mike Burston Oct 23, 2001

ShirtLifter8-Nov-01 22:14

ShirtLifter

8-Nov-01 22:14

You're a very helpful person aren't you!

Well, looking at what you've contributed to this site, suggests you don't know the answer to this poor persons question.

Never mind I will email him a parser and GUI for his calculator.