C / C++ / MFC

Setting a controls background to transparent

14-Sep-09 10:06

I just tried your code snippet on a modified c:\boot.ini file and it read fine. The tab character was in pBuf.

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Active windows

mishudev14-Sep-09 8:58

mishudev

14-Sep-09 8:58

Hi all
i am new member of this forum.I need some help for Get Active window name.Can any one give me API or function name?
Thank in advance.

Re: Active windows

Randor 14-Sep-09 9:52

Randor

14-Sep-09 9:52

You can use the GetForegroundWindow Function[^] and the GetWindowText Function[^].

Best Wishes,
-David Delaune

Deepak.Prahlad14-Sep-09 7:47

14-Sep-09 7:47

Hi I want to set the background of a static control to transparent. How to do this?

I tried the methode described in MSDN ( using the ON_WM_CTLCOLOR() and ON_WM_ERASEBKGND() ) but not working.

My intention is to set the background to a blue gradient or just a solid fill. I have lot of static controls and check boxes in my dialog. I mangaed to set the background of my dialog to solid blue with the help of MSDN documentation. But static control background becomes white whatever i do according to the documentation. Compailer complainted that m_brush is not declaired. I declaired it as CBrush m_brush; in .h file. I have not initialized and not sure how to initialise it.

Am i doing something wrong? Please help. Below is what I got from the MSDN (FYR)

HBRUSH CTestDlg::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
   // Call the base class implementation first! Otherwise, it may
   // undo what we're trying to accomplish here.
   HBRUSH hbr = CDialog::OnCtlColor(pDC, pWnd, nCtlColor);

   // Are we painting the IDC_MYSTATIC control? We can use
   // CWnd::GetDlgCtrlID() to perform the most efficient test.
   if (pWnd->GetDlgCtrlID() == IDC_MYSTATIC)
   {
      // Set the text color to red
      pDC->SetTextColor(RGB(255, 0, 0));

      // Set the background mode for text to transparent 
      // so background will show thru.
      pDC->SetBkMode(TRANSPARENT);

      // Return handle to our CBrush object
      hbr = m_brush;
   }
   return hbr;
}

BOOL CTestDlg::OnEraseBkgnd(CDC* pDC)
{
      // Set brush to desired background color
      CBrush backBrush(RGB(255, 128, 128));

      // Save old brush
      CBrush* pOldBrush = pDC->SelectObject(&backBrush);

      CRect rect;
      pDC->GetClipBox(&rect);     // Erase the area needed

      pDC->PatBlt(rect.left, rect.top, rect.Width(), rect.Height(),
          PATCOPY);
      pDC->SelectObject(pOldBrush);
      return TRUE;
}

Randor 14-Sep-09 9:50

Randor

14-Sep-09 9:50

Hi Deepak,

You need to return((HBRUSH)GetStockObject(NULL_BRUSH)); in your WM_CTLCOLOR handler.

Use of NULL_PEN, NULL_BRUSH, and HOLLOW_BRUSH[^]

Best Wishes,
-David Delaune

Deepak.Prahlad14-Sep-09 19:22

14-Sep-09 19:22

Randor wrote:
return((HBRUSH)GetStockObject(NULL_BRUSH));

Dear Randor,

It done the job for static texts. Thank you very much. But the check boxes give COLOR_BTNFACE as background colour if I return it only for the static text.

if (pWnd->GetDlgCtrlID() == IDC_STATIC_DATE)
   {
      // Return handle to our CBrush object
      hbr = ((HBRUSH)GetStockObject(NULL_BRUSH));
   }
   return hbr;

If I return it for all controls, check boxes become black. What to do?
sorry if I am asking silly questions.. I am newbie Frown | :(

Thanks in advance!
Deepak

Randor 15-Sep-09 0:19

Randor

15-Sep-09 0:19

Hi Deepak,

Deepak.Prahlad wrote:
If I return it for all controls, check boxes become black. What to do?

If you are custom coloring multiple controls in your WM_CTLCOLOR handler then it would be better to use a switch statement with a single call to the pWnd->GetDlgCtrlID() function.

To handle both the static and the checkbox try something like this:

int iCtrlID = pWnd->GetDlgCtrlID();
switch(iCtrlID)
{
	case IDC_STATIC_DATE:
	{
		pDC->SetBkMode(TRANSPARENT);
		hbr = ((HBRUSH)GetStockObject(NULL_BRUSH));
		break;
	}
	case IDC_YOUR_CHECKBOX:
	{
		RECT r;
		pWnd->GetClientRect(&r);
		pDC->BitBlt(0, 0, r.right - r.left, r.bottom - r.top, pWnd->GetDC(), r.left, r.top, SRCCOPY);
		hbr = ((HBRUSH)GetStockObject(NULL_BRUSH));
		break;
	}
	default:
		break;
}

Deepak.Prahlad15-Sep-09 1:08

15-Sep-09 1:08

Dear Randor,

Once again thank you for your great help. That did the Trick! I have one more issue in the static text. It doesn't properly update the text. I think it is writing over the old text in each iteration. I am using a static text to display the current time. In each second it is being updated with new time with the help of a timer. It was working fine before we went for the transparent background. now it seems to be overwriting. Do I need to clear the text before updating it? I mean use some thing like

SetDlgItemText(IDC_STATIC_DATE,_T("        ")//8 space characters
SetDlgItemText(IDC_STATIC_DATE,_T("HH:MM:SS")//Actual time

Thank you
Deepak

Randor 15-Sep-09 3:06

Randor

15-Sep-09 3:06

Hi Deepak,

Are you Invalidating the CStatic window after you update the text?

SetDlgItemText(IDC_STATIC_DATE,_T("HH:MM:SS"));
//Update the window too
CWnd *pWnd = GetDlgItem(IDC_STATIC_DATE);
if(NULL != pWnd)
{
	pWnd->Invalidate();
	pWnd->UpdateWindow();
}

Best Wishes,
-David Delaune

Deepak.Prahlad15-Sep-09 4:55

15-Sep-09 4:55

Randor wrote:
Invalidating the CStatic window

Hi David,

That has no effect. Cry | :((

Thanks
Deepak

Randor 15-Sep-09 5:42

Randor

15-Sep-09 5:42

Sorry... I somehow misunderstood what your trouble was. D'Oh! | :doh:

Now I understand your problem. The parent needs to redraw what was under the child something like this:

CWnd *pWnd = GetDlgItem(IDC_STATIC_DATE);
if(NULL != pWnd)
{
	RECT r;
	pWnd->GetWindowRect(&r);
	ScreenToClient(&r);
	InvalidateRect(&r);
}

Best Wishes,
-David Delaune

Deepak.Prahlad15-Sep-09 23:25

15-Sep-09 23:25

Hi David,

It is working nicely now.
But I could not set text colour for the Check boxes and Radio buttons. IT shows up as black always regardless of SetTextColor(). Is there any other thing I have to do in CtlColor method for it? Also how to control the colour of Tab control ?

Thank You
Deepak

Randor 16-Sep-09 1:50

Randor

16-Sep-09 1:50

Hi Deepak,

This tells me that your Windows theme is overriding the colors. You can disable the theme for an individual control using the SetWindowTheme Function[^]. Lets use your checkbox as an example:

case IDC_YOUR_CHECKBOX:
{
	RECT r;
	pWnd->GetClientRect(&r);
	pDC->BitBlt(0, 0, r.right - r.left, r.bottom - r.top, pWnd->GetDC(), r.left, r.top, SRCCOPY);
	pDC->SetBkMode(TRANSPARENT);
	hbr = ((HBRUSH)GetStockObject(NULL_BRUSH));
	pDC->SetTextColor(RGB(255, 0, 0));
	SetWindowTheme(pWnd->m_hWnd, L"", L"");
	break;
}

We have disabled the theme on this control. It might not be what you want, maybe it will be ugly in your eyes. Smile | :)

Best Wishes,
-David Delaune

Deepak.Prahlad16-Sep-09 2:21

16-Sep-09 2:21

Compiler complained that

Error	1	error LNK2001: unresolved external symbol __imp__SetWindowTheme@12	LoggerDlg.obj
Error	2	fatal error LNK1120: 1 unresolved externals	C:\Documents and Settings\deepak.p\Desktop\Logger Working\Logger 13-Sep-2009

From the documentation you provided it says to include "uxtheme.h" but it din't solved the compile error.

Do we need any other includes ?

Randor 16-Sep-09 2:57

Randor

16-Sep-09 2:57

Add:

#include "uxtheme.h"
#pragma comment(lib, "uxtheme.lib")

Or you can add the uxtheme.lib into the project linker settings.

Best Wishes,
-David Delaune

Deepak.Prahlad22-Sep-09 23:25

Can we access session cookies from C++/VC++ code?

22-Sep-09 23:25

Dear David,

Sorry for the late reply. I was on leave due to some health problems Sigh | :sigh:

I tried your suggestion for the check boxes. But it shows some strange behaviors. Okay I will go with the black letters. But can you please tell me how to change the Tab controls color and button colors?

Thanks in advance
Deepak

sarat14-Sep-09 6:08

Re: Can we access session cookies from C++/VC++ code?

14-Sep-09 6:08

Can we access session cookies from C++/VC++ code.
How to do that?
I need to store data in session cookies when I open any web based client, and I need to access the cookies from VC++ code, I need help in that whether we can
Do that? Please somebody can let me know how to do that if there is any solution.

Thank you in advance.

David Crow14-Sep-09 7:05

Re: Can we access session cookies from C++/VC++ code? [modified]

14-Sep-09 7:05

Are you wanting to do it via a BHO, or are you just wanting to open the .txt file?

sarat16-Sep-09 6:54

Re: Can we access session cookies from C++/VC++ code?

16-Sep-09 6:54

I am hosting web browser on a dialog( which is MFC dialog) and navigating to a link ( link ->which is a client to a database of articles)
when I open an article in the browser which I hosted on MFC dialog I will save the article id ( somehow I will get it ) in a session cookie.
Later on I need to access the session cookie from MFC code.
how to do that any idea please?

I am using CWebBrowser2 calss object as web browser, and useing CWebBrowser2 ::Navigate2 interface method to navigate to the specified link.

modified on Wednesday, September 16, 2009 1:01 PM

David Crow16-Sep-09 6:59

Re: Can we access session cookies from C++/VC++ code?

16-Sep-09 6:59

sarat wrote:
...I will save the article id ( somehow I will get it ) in a session cookie.
Later on I need to access the session cookie from MFC code.
how to do that any idea please?

If you have code for creating a cookie, why can't you access it?

sarat16-Sep-09 8:16

Re: Can we access session cookies from C++/VC++ code?

16-Sep-09 8:16

I create cookeies thru .aspx page and post it to local machine with another .aspx page. the code is in aspx now i need to access the cookies from MFC code

David Crow16-Sep-09 8:19

Re: Can we access session cookies from C++/VC++ code?

16-Sep-09 8:19

See here.

sarat22-Sep-09 23:52