C / C++ / MFC

29-Mar-03 5:33

Why does the colour black get displayed transparently in a CListCtrl given an associated imagelist.
How do I preserve the black colour .. ?

Thanks in advance.

Gary R. Wheeler29-Mar-03 5:49

Gary R. Wheeler

29-Mar-03 5:49

Depending upon how you create the image list, the color black can be used as a mask value. Pixels in the bitmaps that are the mask color are displayed as transparent.

The easiest way to handle transparency with an image list is to use icons, rather than ordinary bitmaps.

Software Zen: delete this;

JamesLaing29-Mar-03 5:57

29-Mar-03 5:57

Thanks Gary for the reply.

So, how do I specify a different mask colour other than black so that the black can be preserved.
The imagelist that I am using works just fine with the rest of the application and yes it is constructed from a bitmap.

Thanks.

RobJones29-Mar-03 6:46

RobJones

29-Mar-03 6:46

What I do is color the "Transparent" part of the bitmap to a purple/pinkish color and set the mask to that color.. like this..

CImageList imageList;
CBitmap bitmap;

bitmap.LoadBitmap(IDB_TOOLBAR);
imageList.Create(26, 26, ILC_COLORDDB|ILC_MASK, 0, 0);
imageList.Add(&bitmap, RGB(255,0,255)); // PURPLE COLOR

Rob..

Whoever said nothing's impossible never tried slamming a revolving door!

JamesLaing29-Mar-03 8:47

29-Mar-03 8:47

Thanks for the reply.

Thanks for the suggestion, but my problem does not involve transparent areas of the source bitmap but the default drawing of any black pixels transparently.

I already have an Imagelist defined for use in the application and I use a temporary DC to draw to prior to using the TransparentBlt function for transparent rendering.

My question is how do I honour the black pixels in the bitmaps when providing an ImageList for a CListCtrl using the .SetImageList function. When the images are displayed in the list, the black pixels are rendered transparently.
How do I prevent or circumvent this ?

Thanks in advance.

Gary R. Wheeler29-Mar-03 13:40

Gary R. Wheeler

29-Mar-03 13:40

If you choose another color as the mask color (purple = RGB(255,0,255) in the example earlier in the thread), then that color is treated as transparent, and black is just another color in the bitmap. This is the standard behavior regarding the list control and imagelists.

You mentioned using TransparentBlt. From the MSDN:

BOOL TransparentBlt(
  HDC hdcDest,        // handle to destination DC
  int nXOriginDest,   // x-coord of destination upper-left corner
  int nYOriginDest,   // y-coord of destination upper-left corner
  int nWidthDest,     // width of destination rectangle
  int hHeightDest,    // height of destination rectangle
  HDC hdcSrc,         // handle to source DC
  int nXOriginSrc,    // x-coord of source upper-left corner
  int nYOriginSrc,    // y-coord of source upper-left corner
  int nWidthSrc,      // width of source rectangle
  int nHeightSrc,     // height of source rectangle
  UINT crTransparent  // color to make transparent
);

<listing>Parameters
...
crTransparent 
[in] The RGB color in the source bitmap to treat as transparent.</listing>

In this case, you would need to pass cdTransparent as whatever color you were using as the transparency color (again, RGB(255,0,255) from the example).

Software Zen: delete this;

JamesLaing29-Mar-03 23:33

Opening Recordset Using CRecordset

29-Mar-03 23:33

Thats great, now I understand.
Thanks very much for the help.

Cheers.

jayesh Bang29-Mar-03 4:50

jayesh Bang

29-Mar-03 4:50

I am try to open a table using Open() method of CRecordset
If I gave * in Query then it running well.But if I gave a perticuler Column Name then Open() method giving Error
'Invalid Descriptor Index'
Is there some one who can help me ?

N'Joy

Re: Opening Recordset Using CRecordset

RaajaOfSelf29-Mar-03 5:52

RaajaOfSelf

29-Mar-03 5:52

Please give the exact code

winpcap

summo29-Mar-03 2:10

summo

29-Mar-03 2:10

Using winpcap
I want the Filter string for "pcap_compile" function that can capture all the traffic passing through the network when applied to the filter funtion "pcap_setfilter".
Please refer any material or helping document that shows which strings are allowed and which are not like I am trying "tcp and udp" but this string fails. Confused | :confused:

Reply me soon

Re: winpcap

Bartosz Bien29-Mar-03 11:10

Bartosz Bien

29-Mar-03 11:10

Check http://www.mail-archive.com/winpcap-users@winpcap.polito.it/msg00790.html.

I hate when someone says "soon" Wink | ;)

Regards,
BB

ShellExecute and IE

tinkywinky29-Mar-03 1:51

tinkywinky

29-Mar-03 1:51

Hello, I have two little questions :

in my progr I use ShellExecute to open an internet link, and each time I call ShellExecute the page is opened in the same IE window.. how to open a new window ?

And the second (stupid!) one, how to add a ActiveX control on a dialog in VS .NET (like an IE control...) ? I didn't find the option like in VC++ 6..

Tkanks!

valikac29-Mar-03 6:13

valikac

29-Mar-03 6:13

Interesting. Consider CreateProcess().

Kuphryn

Anders Molin29-Mar-03 6:55

Anders Molin

29-Mar-03 6:55

tinkywinky wrote:
in my progr I use ShellExecute to open an internet link, and each time I call ShellExecute the page is opened in the same IE window.. how to open a new window ?

That's actually an options in IE where people can select if pages should recycle windows or open in a new one...

Tools->Internet Options->Advanced
Under browsing there's a checkbox called "Reuse Windows for Launching Shortcuts". If you wanna force it try createprocess as already sugested...

- Anders

Money talks, but all mine ever says is "Goodbye!"

Stephane Rodriguez.30-Mar-03 8:44

Stephane Rodriguez.

30-Mar-03 8:44

Use the opennew verb instead of open.