Re: Code to find cameras and scanners - C / C++ / MFC Discussion Boards

Re: Silly question about repaint

valikac2-Jun-03 6:46

valikac

2-Jun-03 6:46

One solution is Invalidate().

Kuphryn

Re: Silly question about repaint

David Crow2-Jun-03 6:49

David Crow

2-Jun-03 6:49

I've got the same thing with one of my SDI apps, but it works fine. What styles are you using to create the dialog with?

Re: Silly question about repaint

doctorpi2-Jun-03 7:00

doctorpi

2-Jun-03 7:00

Hi David
My styles are

Style : Child
Border : None

Nothing more checked in this dialog.

Hi Kuphryn
Where I have to put the Invalidate() meantime I am in the modal dialog?

Bsst Regards

Re: Silly question about repaint

David Crow2-Jun-03 7:02

David Crow

2-Jun-03 7:02

Just for grins, change the style to Popup and see what happens.

Re: Silly question about repaint

doctorpi2-Jun-03 7:09

doctorpi

2-Jun-03 7:09

Hi guys
I've discovered part of the problem.
I'm using CLabel class and when is repainted when the modal dialog is open the values are centered instead that left aligned amd made me thing that I had a repaint problem.
I don't know where could be the problem. I'll try to find.
Thanks
Dr.Pi

Re: Silly question about repaint

David Crow2-Jun-03 7:19

David Crow

2-Jun-03 7:19

It sounds like you are using a CListView. If that is the case, you can change the alignment (e.g., LVCFMT__LEFT) when you are adding the columns.

Code to find cameras and scanners

jleno2-Jun-03 5:55

jleno

2-Jun-03 5:55

I'm searching for an example of how to detect all the cameras and scanners attached to a PC (preferably serial and USB but I'll settle for USB only) I've tried using the STI and WIA apis, and those work, but there are two problems. One, they each support only a couple of OS versions, and I'd like something that works 98 through XP. Two, they only detect devices that export a TWAIN interface.

I want to get the name of each device. I did find some code that walks the USB bus, but there didn't seem to be a way to distinguish among returned devices.

Is there a good way to accomplish this that would work for Win 98 and on? Thanks.

Re: Code to find cameras and scanners

Ryan_Roberts2-Jun-03 6:15

Ryan_Roberts

2-Jun-03 6:15

You can use directshow to enumerate AV capture devices(If their drivers are WDM complient.)

Have a look at the AMCap sample in the DirectShow SDK.

http://www.microsoft.com/Developer/PRODINFO/directx/dxm/help/ds/appdev/Enumerate_Access_Hardware_Devices.htm#amcap_enumeration[^]

Ryan

"Everybody has a right to be stupid, but
some people abuse the privilege."

Uncle Joe Stalin

Re: Code to find cameras and scanners

Andrew Walker2-Jun-03 13:42

Andrew Walker

2-Jun-03 13:42

Ryan S Roberts wrote:
You can use directshow to enumerate AV capture devices(If their drivers are WDM complient.)

It also finds VFW Devices

CPropertySheet

K. Shaffer2-Jun-03 5:54

K. Shaffer

2-Jun-03 5:54

I am trying to overide some functions in CPropertySheet. I created a CPropertySheet derived class and added it to my project. when I do this in the main program, everything is cool:

//in main.cpp
CMyPropertySheet m_sheet(IDS_CODE);
m_sheet.AddPage(&entry);
m_sheet.AddPage(&approach);

But if I delare the object in the header, like this I get errors:

//in main.h
CMyPropertySheet* m_sheet;
//in main.cpp
m_sheet = new CMyPropertySheet(IDS_CODE);
m_sheet.AddPage(&entry);
m_sheet.AddPage(&approach);

Errors I get are:
error C2228: left of '.AddPage' must have class/struct/union type

I am assuming that the error is in the way I am trying to declare the CMyPropertySheet object, but I cant think of any other way. What am I doing wrong?

Kevin Shaffer
kshaff03@msn.com

Re: CPropertySheet

Joan M2-Jun-03 6:02

Joan M

2-Jun-03 6:02

in the first way you use directly an object, and in the second method you use a pointer to an object...

Then your problem should be solved by changing m_sheet.AddPage(&entry); for m_sheet->AddPage(&entry);

it's an usual mistake...

take a look at the error: error C2228: left of '.AddPage' must have class/struct/union type if what is in the left of the member (method, function or variable) is a class, a union or a struct you will need the "." elsewhere you'll need the "->".

hope this helps.

Re: CPropertySheet

K. Shaffer2-Jun-03 6:12

K. Shaffer

2-Jun-03 6:12

Got it, thanks!

I learned all of my object-oriented programming in Java, still trying to work out all the subtle differences. Thanks.

Kevin Shaffer
kshaff03@msn.com

Re: CPropertySheet

Joan M2-Jun-03 6:14

Joan M

2-Jun-03 6:14

That happens to all of us... subtle differences are evil! Wink | ;)

you are welcome!

Visual Studio 6 IDE

⁷³Zeppelin2-Jun-03 5:46

⁷³Zeppelin

2-Jun-03 5:46

This question concerns the VS 6.0 IDE environment.
I am working on a rather large project. One convenient thing is that
a separate (console) project contains several classes that we wish to
use in the larger project. Therefore we are looking for a way to (easily)
import these (console) classes into the larger project (SolverGUI).
Can I create the new project (call it SolverGUI) using the MFC appwizard and then go to Project-Insert Project into Workspace and insert the console project into the SolverGUI project? This is possible, I know, but after doing that, can I use the classes in SolverConsole in SolverGUI? Is it as simple as declaring the header files in SolverGUI where I want to use the console classes, or do I have to add new classes to SolverGUI to use them?
ie: Is communication between projects possible?

Re: Visual Studio 6 IDE

Roger Allen3-Jun-03 2:47

Roger Allen

3-Jun-03 2:47

Sounds like you need to wrap the common classes between the console/GUI app into a library or DLL. You can then build this and get your console/GUI versions to link to the lib/dll. This should also keep both projects upto date with the common code base, as changing one, changes the other.

Inserting a project into the current workspace only lets you switch between them. You can set build dependencies so that everything gets built in the right order etc.

Roger Allen
Sonork 100.10016

Were you different as a kid? Did you ever say "Ooohhh, shiny red" even once? - Paul Watson 11-February-2003

Re: Visual Studio 6 IDE

⁷³Zeppelin3-Jun-03 14:56

⁷³Zeppelin

3-Jun-03 14:56

That clarifies things greatly. I think I will take this approach.

Thank you.

missing storage class or type identifier

mr20032-Jun-03 5:24

mr2003

2-Jun-03 5:24

i keep getting this error,, how can I fix it?

I have the follwing function defined as public in the View class.

Void LoadBitmap (CString file);

and I get an error saying : missing storage-class or type specifiers

help me out Frown | :(

Ehsan Behboudi

Re: missing storage class or type identifier

Joaquín M López Muñoz2-Jun-03 5:26

Joaquín M López Muñoz

2-Jun-03 5:26

Could it be that you've got to write void instead of Void?

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: missing storage class or type identifier

mr20032-Jun-03 6:49

mr2003

2-Jun-03 6:49

you are THE MAN,,,,

Ehsan Behboudi

Jumping child windows during scroll

pankajdaga2-Jun-03 5:21

pankajdaga

2-Jun-03 5:21

Hi all,

I have a particular UI problem that I am seeking help with. I have a parent window that can be zoomed and scrolled. The parent window has a few child windows. When I scroll the parent window I have to recalculate the new position of the child windows and the I call ::MoveWindow on them. However, there is a slight jump in the child windows during scroll and the movement does not look fluid. Is there any way to eliminate this jumping behavior?

I tried the DeferWindowPos API and did not get any noticable improvement Frown | :(

Thanks for any help you might give me.

Pankaj

Without struggle, there is no progress

Re: Jumping child windows during scroll

basementman2-Jun-03 7:35

basementman

2-Jun-03 7:35

What I have done in the past is to hide the windows, move them, then show them. Only one flicker.

// hide windows
for (...)
{
pWnd->ShowWindow(SW_HIDE);
pWnd->MoveWindow(...);
}

for (...)
pWnd->ShowWindow(SW_SHOW);

Re: Jumping child windows during scroll

Roger Allen3-Jun-03 2:55

Roger Allen

3-Jun-03 2:55

Try modifying you OnEraseBkGnd as follows:

BOOL CSomeView::OnEraseBkgnd(CDC* pDC) 
{
	CRect	clip;
	static int dont_erase_indexes[] =
	{
	// add control id's here to stop them flickering during a re-draw
	IDC_TITLE_PROMPT,
	IDC_TITLE,
	IDC_TRAY,
	IDC_ASSAY
	};

	pDC->SaveDC();
	for (int i = 0; i < sizeof(dont_erase_indexes[) / sizeof(int); i++)
	{
		// only exclude the visible windows
		CWnd *pWnd = GetDlgItem(dont_erase_indexes[[i]);
		if (pWnd && pWnd->IsWindowVisible())
		{
			pWnd->GetWindowRect(&clip);		// get rect of the control
			ScreenToClient(&clip);
			pDC->ExcludeClipRect(&clip);
		}
	}
	pDC->GetClipBox(&clip);
	pDC->FillSolidRect(clip, GetSysColor(COLOR_BTNFACE));
	pDC->RestoreDC(-1);
	return FALSE;
}

I usually fins when a window is re-drawn this solves many flicker problems

Roger Allen
Sonork 100.10016

Were you different as a kid? Did you ever say "Ooohhh, shiny red" even once? - Paul Watson 11-February-2003

MFC MDI with an edit box on toolbar

mahoni_5012-Jun-03 5:19

mahoni_501

2-Jun-03 5:19

I am working on an MFC MDI project. I used internet explorer rebar as the toolbar option at the beginning of the project.

I added an edit box on the toolbar. Now, I want to get the text entered in this editbox but I could not find how I can do it.

Can anybody help me ?

Thanx...

Difference in VC++ 6.0 and C++.NET

mr20032-Jun-03 4:48

mr2003

2-Jun-03 4:48

Hi,

I used to program in VC++ 6.0 about two years ago, and I'm back in programming except I am using .net
Is there any change in functions and classes between them?

Ehsan Behboudi

Re: Difference in VC++ 6.0 and C++.NET

Navin2-Jun-03 5:11

Navin

2-Jun-03 5:11

Most of VC.NET is backwards compatible with VC 6.0.

However, they have tried to make it more standards-compliant. You will get warnings about some code that is non-standard and deprecated. For example, they deprecate the use of "old" IOStreams. So if you have code that does this:

#include <iostream.h>

...
cout << "Hey there!";

You will get a warning. You should replace it with the "new" IOStream headers:

#include <iostream>

...
std::cout << "Hey there!";

Also, it is possible (via the Preferences dialog) to force "for" loops to conform to the C++ standard (finally!), for example, you can get this standards-compliant code to compile (in VC 6 it would not):

for(int i = 0; i < somenum; i++)
...

for(int i = 0; i < someothernum; i++)
...

"When a man sits with a pretty girl for an hour, it seems like a minute. But let him sit on a hot stove for a minute and it's longer than any hour. That's relativity." - Albert Einstein

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