C / C++ / MFC

Re: How to clear CFrameWnd

19-Jun-03 0:14

I wanted to post the comment about win98 here hoping that someone would reply. Its better to post questions here than to email because there is a chance that someone else will see your post and have an answer...

John

How to clear CFrameWnd

Shay Harel18-Jun-03 8:21

Shay Harel

18-Jun-03 8:21

Hi,

I have a window that inherits from CFrameWnd.
I did some drawings inside and I want to clear the window and start from a clean one,

How do I do it ?

Shay

Maximilien18-Jun-03 8:49

Maximilien

18-Jun-03 8:49

I'm not sure what you want to do.

how/where do you paint ? You could "empty" the the view with a FillRect on the entire view area.

Maximilien Lincourt
For success one must aquire one's self

Re: How to clear CFrameWnd

Shay Harel18-Jun-03 9:12

Shay Harel

18-Jun-03 9:12

I already found it:

this->Invalidate (true).

But I have another one:

I created a tool bar on my FrameWand but when I scroll it, the tool bar scroll with it how can I make it stay there ????

Thanks

Shay

Possible reason why a fileread fails?

georgiek5018-Jun-03 8:10

georgiek50

18-Jun-03 8:10

I have a little function which reads from a file:

int Read(int iFile, char *szData, size_t iBytes)
{	
        int iReadThis = 0;

	while (iBytes > 0)
	{
		iReadThis = read(iFile, szData, iBytes);

		szData += iReadThis;

		iBytes -= iReadThis;

		// End of File?
		if ( iReadThis == 0 )
			return 1;
	}

	return 0;
}

and I am trying to read through an entire file, say 1 MB at a time or 4 bytes at a time; In either case, I can not read through the whole file because the functions returns 1 at some point and it's not the end of the file either (checked the position of the file pointer). What could be the reason for this and what is a workaround for it?

Re: Possible reason why a fileread fails?

AlexO18-Jun-03 8:18

AlexO

18-Jun-03 8:18

1. check for error
georgiek50 wrote:
if ( iReadThis == 0 )
{ //use ::ferror here to check if it is an error
return 1;
}

it is also helpful in debug to put "@err,hr" into watch window, that way you can observe system error.
2. Where did iBytes come from?
3. how did you allocate szData?

Re: Possible reason why a fileread fails?

georgiek5018-Jun-03 14:17

georgiek50

18-Jun-03 14:17

Error return 0, iBytes come from a while loop say 64 at a time or more or less until eof is reached and szData is allocated with new and deleted each time after processing is done. The only way I have found around this is to seek 1 byte ahead every time this occurs but this is does not seem practical enough. Are there any "special" bytes in a file that when read would cause a read to just not respond, or return 0?

Question about Kodak CImgEdit Control

MarcoNedwig18-Jun-03 7:08

MarcoNedwig

18-Jun-03 7:08

I'm using the Active X Control CImgEdit in one of my apllications to display .pcx files. My problem is that during runtime the control gets more and more memory until the application collapses.
I use :
m_CtrlImageEdit.SetImage ("<filename>.pcx");
m_CtrlImageEdit.Display();

I havent't found a method to "unset" the image assigned to the control.
So every new file assigned to the control and is displayed gets new memory.

So does everyone know a solution to remove the images set by SetImage Method or another way to avoid this memory problem?

Getting Started in Visual C++.NET

Nino_118-Jun-03 6:11

Nino_1

18-Jun-03 6:11

Hello All CPians,

I am working towards getting a start on the VC++.NET side of VS.NET.

I realize this is not an easy language to start with, I was wondering how to get started. Should I just get a book on VC++.NET and go to town? What do you guys recommend??

Thanks In Advance

Tony

valikac18-Jun-03 6:47

valikac

18-Jun-03 6:47

I highly recommend that you master C++ before going into windows programming.

Kuphryn

Nino_118-Jun-03 15:48

Nino_1

18-Jun-03 15:48

kuphryn wrote:
master C++ before going into windows programming

Sounds Good! where do you recommend I start with C++ programming?

Borland C++? or which one.

Thanks

Tony

valikac19-Jun-03 6:41

valikac

19-Jun-03 6:41

I recommend Visual C++ under windows platform and Borland Kylix under Linux. As for fundamental book, I recommend C++ How to Program by Deitel&Deitel.

Kuphryn

Background color of Dialog

Nino_122-Jun-03 11:11

Nino_1

22-Jun-03 11:11

Many Thanks !!!!!!

Tony

ToolTip Problem

Kyudos18-Jun-03 6:05

Kyudos

18-Jun-03 6:05

I'm trying to get tooltips working on my dialog. I have a toolbar on the dialog which fires tooltip notifications and the tooltips display fine, but tooltips 'inside' frames don't fire the notification and I don't get tooltips.

Anyone know why not?

Dan

act_x18-Jun-03 5:58

act_x

18-Jun-03 5:58

How can I change the background color of a dialog ?

Re: Background color of Dialog

Harsha Gopal18-Jun-03 6:22

Harsha Gopal

18-Jun-03 6:22

You can go to the WM_PAINT (OnPaint()) of the dialog and add the following code

CRect rect;
CBrush brush(RGB(100, 0, 0));
dc.GetWindow()->GetWindowRect(&rect);
ScreenToClient(&rect);
dc.FillRect(&rect, &brush);

dc is CPaint dc(this);

Harsha
----------------------------------
http://www.ece.arizona.edu/~hpg
----------------------------------

Re: Background color of Dialog

kochhar18-Jun-03 12:38

kochhar

18-Jun-03 12:38

One way is to override OnCtlColor(), as follows:

(1) In your message map, add:

<br />
   	ON_WM_CTLCOLOR()<br />

(2) Then, add the following function to your Dialog class:
(replace CMyDialog with whatever is the proper name in your case)

<br />
HBRUSH CMyDialog::OnCtlColor(CDC *pDC,CWnd *pWnd,UINT nCtlColor)<br />
{<br />
	HBRUSH hbr = CDialog::OnCtlColor(pDC,pWnd,nCtlColor);<br />
<br />
	if(nCtlColor == CTLCOLOR_DLG)<br />
	{<br />
		// Dialog background color (Blue)<br />
		hbr = CreateSolidBrush(RGB(0,0,255));<br />
		return hbr;<br />
	}<br />
<br />
	return hbr;<br />
}<br />

You can use this method to change the color of pretty much any
element of your dialog.

HELP: source code of TIFF viewer, thanks

Anonymous18-Jun-03 5:50

Anonymous

18-Jun-03 5:50

Hi, I am going to write a tiff file viewer, but I don't know the format of the
tiff file. Here I ask my questions,

(1). I googled the format of tiff and didn't find any help information, anyone
can show me an URL to learn the tiff format?
(2) can somebody show me the source code of tiff viewer? How is a tiff file
compressed and displayed?

(3). WHAT I WANT TO DO IS: to display the result of a window moving(1024*768)
on a very large picture(8192*4096). My goal is to MINIMIZE the data to be
transfered over ethernet at each display frame.
Say, I want to have my viewer display 1024*768 pixels at a time, my mouse
move smoothly to change the position of the window. Thus intuitively, at each
time I only need a small ammount of new pixels to be loaded in the viewer,
because the other part should overlap with the former frame. Is ther any
clever method to minimize the data transfer?? (If it were bmp file, I can
expect this is doable.)

---------------------------
| |-------| moving |
| |Window | --> |
| |-------| |
| whole pic |
|-------------------------|

ZoogieZork18-Jun-03 6:20

ZoogieZork

18-Jun-03 6:20

Anonymous wrote:
anyone
can show me an URL to learn the tiff format?

TIFF format spec (Rev. 6):
http://partners.adobe.com/asn/developer/pdfs/tn/TIFF6.pdf[^]

- Mike

ZoogieZork18-Jun-03 6:24

ZoogieZork

18-Jun-03 6:24

Forgot to mention, there's also libtiff[^], which is free and may be helpful.

- Mike

John M. Drescher18-Jun-03 6:57

18-Jun-03 6:57

Yes. You do not want to implement TIFF from scratch unless you have 6 months extra time on your hands...

John

John M. Drescher18-Jun-03 7:03

18-Jun-03 7:03

Any reason why you are using TIFF? Most developers stay away from TIFF because of the problems with the Unisys patent of LZW.

John

Anonymous18-Jun-03 7:19

Anonymous

18-Jun-03 7:19

Because my advisor(in University) want to write a demo software to implement the senario I described above. We have lots of big tiff file(>22MB) on hands.

John M. Drescher18-Jun-03 7:21

18-Jun-03 7:21

I work in a university and understand...

John