C / C++ / MFC

1-Jun-06 21:45

Hi!

Perhaps it's a silly question, but at the moment I'm really stumped:
I need a window to receive messages from a different application for synchronisation purpose.

In order to have an easy way of showing which messages were received, I've created a dialog (CDialog derived) with a ListBox to trace the messages.
Because I want to use SendMessage(HWND_BROADCAST,...) (and not explicitely find out the hWnd of my dialog), I'd have to make the dialog a TopLevel window.

Unfortunately, I've completely failed to achieve this so far. I thought creating the dialog without giving a parent window would create a TopLevel window, but obviously I was wrong - my SendMessage wasn't received and Spy shows a parent window for my dialog...

Can anyone please give me a little push in the right direction?

Regards,
mav

--
Black holes are the places where god divided by 0...

Nibu babu thomas1-Jun-06 21:57

Nibu babu thomas

1-Jun-06 21:57

mav.northwind wrote:
Unfortunately, I've completely failed to achieve this so far. I thought creating the dialog without giving a parent window would create a TopLevel window, but obviously I was wrong - my SendMessage wasn't received and Spy shows a parent window for my dialog...

SetWindowPos(&wndTopMost, 0, 0, ....) creates a top most window. Is this what you want.

Nibu thomas
A Developer

Programming tips[^] My site[^]

mav.northwind1-Jun-06 22:13

1-Jun-06 22:13

Hi!
Thanks for your response, but this is not what I need.
I don't need the window to be top most (the dialog isn't visible at all in release mode), but TopLevel.
Only TopLevel windows receive messages sent with HWND_BROADCAST...

Regards,
mav

--
Black holes are the places where god divided by 0...

Nibu babu thomas1-Jun-06 22:16

Nibu babu thomas

1-Jun-06 22:16

mav.northwind wrote:
but TopLevel.

All TopLevel windows have Desktop window as their parent. Use SetParent to set the parent to Desktop Window.

Nibu thomas
A Developer

Programming tips[^] My site[^]

mav.northwind1-Jun-06 22:36

1-Jun-06 22:36

Thanks, but that doesn't work either. I tried setting the parent to the desktop window but Spy++ still shows the main application's window as the parent.

I guess I'll opt for the own window class and FindWindow.

Regards,
mav

--
Black holes are the places where god divided by 0...

Viorel.1-Jun-06 22:20

Viorel.

1-Jun-06 22:20

It seems that an MFC application cannot have more than one top-level windows. Therefore, the messages sent by SendMessage(HWND_BROADCAST,...) always reach the main application window instead of your dialog. (Information about how to extend MFC to support multiple top-level windows con be found at http://www.codeproject.com/docview/multitop.asp[^]).

As a possible solution of your problem, since you surely will process broadcasted messages in your main application doing main synchronization tasks, you can simply call there a member function of your debug dialog. (For instance, you can keep a pointer to your debug dialog, which should be null when the dialog is not displayed).

Hope this will help.

mav.northwind1-Jun-06 22:30

Re: Dialog as TopLevel window [modified]

1-Jun-06 22:30

Hi and thanks alot!

It seems as if I have to say goodbye to my initial idea Sigh | :sigh:

. The dialog is part of a DLL that's being loaded by a third-party application I cannot influence.

Then I guess I'll try to give my dialog a special window class I can use in a FindWindow() from the external application and not use HWND_BROADCAST.

Regards,
mav

--
Black holes are the places where god divided by 0...

mav.northwind1-Jun-06 23:04

Re: Dialog as TopLevel window [modified]

1-Jun-06 23:04

Unfortunately, my other idea (setting the class name of the dialog) doesn't work either, because PreCreateWindow (where the class name can be modified) doesn't get called for CDialog derived classes. Mad | :mad:

Is there anything else I can try?

Regards,
mav

--
Black holes are the places where god divided by 0...

-- modified at 5:21 Friday 2nd June, 2006

Although I don't really like the solution, I think I'll go for FindWindow with a special window title. That way I can at least find the dialog...
Thanks für the help.

Viorel.1-Jun-06 23:41

Viorel.

1-Jun-06 23:41

If you just need a dialog box for simple passive spying of your broadcasted messages, I think you can try to create a separate dialog-based application. In this case the dialog window is expected to be the top-level one. You will be able to start this debugging dialog only when you need it, even if the main receiver application is stopped.

Re: Dialog as TopLevel window [modified]

mav.northwind2-Jun-06 5:31

Form's Button not responding

2-Jun-06 5:31

Thanks for the suggestion, but (as always) it's not as simple as that.
I have the dialog in my DLL because I need to raise events to the hosting application from within the same thread that loaded my DLL.
Some events I get come in via remoting from a different thread, so I have to "marshal" (big word for sending a message Smile | :)

) them to the other thread by sending a message to the dialog and have the dialog raise the event.
Now I not only have to send messages to the dialog from within the DLL (where I have access to the dialog's HWND), but from other applications as well. That's the whole reason for my problems...

Well, the constant window title at least works, so I think I'll have to use it for now until I find a better way.

Regards,
mav

--
Black holes are the places where god divided by 0...

Y_Kaushik1-Jun-06 21:39

Y_Kaushik

1-Jun-06 21:39

Hai to all of you
i am new in VC++ and i have make a simple application But
one of the form of that application contain some error..........

Like Whenever i click any button of that form then MessageBox Generate a Message Could not add new member

Note: I have also write the code of button ,yet its not responding accordingly . i don't know where i am lacking

Plz Tell me.....

mailing me
Yogi

Re: Form's Button not responding

Hamid Taebi1-Jun-06 22:35

Hamid Taebi

1-Jun-06 22:35

can you show error message and you get this error only in this application or all projects

whitesky

Customize ColorDialog

velayudhan_raj1-Jun-06 21:21

velayudhan_raj

1-Jun-06 21:21

how to change the background color of a custom color dialog

Re: Customize ColorDialog

Hamid Taebi1-Jun-06 21:37

Hamid Taebi

1-Jun-06 21:37

of course its not a good way but maybe its some helpful to you

<br />
class CMyDialog: public CColorDialog<br />
{<br />
public: <br />
	DECLARE_DYNCREATE(CMyDialog)<br />
	CMyDialog();<br />
	~CMyDialog();<br />
	DECLARE_MESSAGE_MAP()<br />
<br />
	afx_msg HBRUSH OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor);<br />
};<br />
<br />
<br />
<br />
<br />
IMPLEMENT_DYNCREATE(CMyDialog, CColorDialog)<br />
<br />
BEGIN_MESSAGE_MAP(CMyDialog, CColorDialog)<br />
	ON_WM_CTLCOLOR()<br />
END_MESSAGE_MAP()<br />
<br />
CMyDialog::CMyDialog()<br />
{<br />
<br />
}<br />
<br />
CMyDialog::~CMyDialog()<br />
{<br />
}<br />
<br />
<br />
HBRUSH CMyDialog::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)<br />
{<br />
	HBRUSH hbr = CColorDialog::OnCtlColor(pDC, pWnd, nCtlColor);<br />
LOGBRUSH logBrush;<br />
logBrush.lbStyle = BS_HATCHED;<br />
logBrush.lbColor = RGB(100, 192, 192);<br />
logBrush.lbHatch = HS_CROSS;<br />
if(pWnd==this)<br />
SetWindowText("Test");<br />
return CreateBrushIndirect(&logBrush);<br />
}<br />

whitesky

Re: Customize ColorDialog

suja sreekumar1-Jun-06 23:31

suja sreekumar

1-Jun-06 23:31

is there any way to change the color of the buttons and the static texts??

Re: Customize ColorDialog

Hamid Taebi2-Jun-06 1:08

Hamid Taebi

2-Jun-06 1:08

See WM_CTLCOLORSTATIC

whitesky

User interface problem -- check a point is inside a polygon or not

George_George1-Jun-06 21:15

Re: User interface problem -- check a point is inside a polygon or not

1-Jun-06 21:15

Hello everyone,

I have a UI application and I need to display context menu according to whether user clicks inside a polygon or not. So, I think I need to use some algorithms which can check whether a point is inside a polygon.

Does anyone have any ideas or reference materials?

thanks in advance,
George

Stephen Hewitt1-Jun-06 21:20

Stephen Hewitt

1-Jun-06 21:20

Using Win32 this can be done using regions. Create a region in the shape of the polygon then use the PtInRegion function.

Steve

Re: User interface problem -- check a point is inside a polygon or not [modified]

George_George1-Jun-06 21:50

Re: User interface problem -- check a point is inside a polygon or not [modified]

1-Jun-06 21:50

Thank you Steve,

Seems that you like using system internal functions other than implement them by yourself. Smile | :)

Actually, I think I need to implement the algorithm by myself -- a portable algorithm works for both Win32 and Linux. Any ideas or reference materials?

regards,
George

-- modified at 3:51 Friday 2nd June, 2006

Cedric Moonen1-Jun-06 21:57

Cedric Moonen

1-Jun-06 21:57

George_George wrote:
Seems that you like using system internal functions other than implement them by yourself

Why reinventing wheel when it is not necessary ?

George_George wrote:
Any ideas or reference materials?

Is this[^] helpfull ?

Anyway, google[^] is very helpfull also.

Cédric Moonen
Software developer

Charting control

Re: User interface problem -- check a point is inside a polygon or not [modified]

George_George1-Jun-06 22:09

Re: User interface problem -- check a point is inside a polygon or not [modified]

1-Jun-06 22:09

Thank you Cedric,

The material is very helpful.

regards,
George

Stephen Hewitt1-Jun-06 22:10

Stephen Hewitt

1-Jun-06 22:10

There are many methods. One popular one is the "Weiler-Atherton Algorithm".

Steve

Re: User interface problem -- check a point is inside a polygon or not [modified]

George_George1-Jun-06 22:32