Pointing Hwnd to a top-level dialog

[Alexei Kubarev]

Hi...im trying to use a transparency code on my program...

// Set WS_EX_LAYERED on this window 
SetWindowLong(hwnd, GWL_EXSTYLE,
        GetWindowLong(hwnd, GWL_EXSTYLE) | WS_EX_LAYERED);
// Make this window 70% alpha
SetLayeredWindowAttributes(hwnd, 0, (255 * 70) / 100, LWA_ALPHA);

But it seens to me that i cant point hwnd to a top-level dialog...
Can someone help me please?!

P.S.: Newbie speaking...

[Apoch]

How are you getting the hWnd, and where is this code?

[Alexei Kubarev]

Code is from MSDN library

hwnd was on that page... im not sure if im using it right...
I need the transparent dialog box..
My prog has only single dialog box... i want it to be transparent (The perfect solution will be making it transparent when its not active)...

[souldog]

the handle is a member variable of your dialog class.
Use m_hWnd instead.

[Alexei Kubarev]

Okej... but still... im not sure how to...
Can you please modify this code so it will make a window transparent when i click on a button?!
I wrote it like this but it doesnt really work

void CFavoritesDlg::OnButton1()
{
	
	// Set WS_EX_LAYERED on this window 
	SetWindowLong(m_hWnd, GWL_EXSTYLE,
			GetWindowLong(m_hWnd, GWL_EXSTYLE) | WS_EX_LAYERED);
	// Make this window 70% alpha
	SetLayeredWindowAttributes( 0, (255 * 70) / 100, LWA_ALPHA);
}

[Apoch]

What exactly isn't working about it? I dropped that code in a test project and it works fine...


Are you sure you're using Windows 2000 or later?

[Alexei Kubarev]

Im using Win XP...

I just dont know how to use this thingy...
all i did is made a dialog base program...
then i put a button... creat a function for that button... in that buttons function i wrote

void CFavoritesDlg::OnButton1()
{
	
	// Set WS_EX_LAYERED on this window 
	SetWindowLong(m_hWnd, GWL_EXSTYLE,
			GetWindowLong(m_hWnd, GWL_EXSTYLE) | WS_EX_LAYERED);
	// Make this window 70% alpha
	SetLayeredWindowAttributes( 0, (255 * 70) / 100, LWA_ALPHA);
}

Nothing more...
And i get a linkin problem now... before i just had an error...

[Apoch]

Add this line at the beginning of your OnButton1 function:

SetWindowText("Window should now be transparent.");

and see if the title of the window changes when you click the button.


Also, it'd help a LOT if you would say what errors you are getting.

[Alexei Kubarev]

Sure -- FATAL LINKING ERROR

P.S.: .NET studio starts piising me off..lol

[Apoch]

Have you tried completely rebuilding the solution? (i.e. Clean Solution, Build Solution)

[Alexei Kubarev]

Okej... thanx for help with this problem... its working... all i needed is a reboot...lol

But more advanced problem_! Making it transparent ONLY When its not active...
How shall i do that?!
I mean when isa active -- it will be 100% visible...
But when not... about 70% visible...
Plus Button1 only turns this on...

Possible to do that?!

[Apoch]

Trap the WM_GETFOCUS and WM_KILLFOCUS messages; in WM_GETFOCUS, call your transparency code. In WM_KILLFOCUS, call SetWindowLong() and remove the WS_EX_LAYERED flag.


Or you can call UpdateLayeredWindow() and set the transparency to 0 when you get a WM_KILLFOCUS.

[Alexei Kubarev]

okej... thanx.. i will try to do that...
Bzway... How do i open a ClassWizard?? im on a .NET 2003 now... i had VS 6.0 before... cant find anything like that...

[Alexei Kubarev]

Still cant do that...Somehow i just dont get how to do that :S

Trap it... how?!
Where shall i put the code and WHAT code?!