C / C++ / MFC

17-Oct-01 16:32

I've got a class to create a window in Win32, and one to create a bitmap button. When I resize the window, I've tried calling MoveWindow or SetWindowPos, both cause the buttons to flicker terribly. I know the problem is here because I killed all drawing in the window, so the background is never drawn at all. Can anyone suggest if there is anything I can do to make my buttons move nicely without flicker ?

Christian

As I learn the innermost secrets of the around me, they reward me in many ways to keep quiet.

Men with pierced ears are better prepared for marriage. They've experienced pain and bought Jewellery.

kumar_p317-Oct-01 16:51

kumar_p3

17-Oct-01 16:51

Hi,

U need to use LockWindowUpdate(which temporarily stops
the WM_PAINT mesgs) and after ur
moving is completed, call UnlockWindowUpdate
to again continue drawing.

Hope it helps....

Michael Dunn17-Oct-01 19:55

Michael Dunn

17-Oct-01 19:55

It sounds like your WM_ERASEBKGND handler repaints the entire background. If that's the case, it's painting over the buttons, which in turn have to be repainted, and thus you get flicker.
First thing I'd try is, in your WM_ERASEBKGND handler, only repaint the necessary portion (by calling GetUpdateRect()) so you won't always paint over all your buttons.

--Mike--
http://home.inreach.com/mdunn/
"....." -- Silent Bob
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your

with

and

Christian Graus17-Oct-01 20:01

17-Oct-01 20:01

Would this be the case even if I set the PaintStruct's erase member to FALSE ? I did that and also stopped my own code from drawing a rectangle over the area, so that the Window background was whatever was under it on creation ( because it was never drawn ), but it still flickers on resize. The above suggestion did not help either, although I was glad to learn the function existed, it did not solve the problem.

Christian

As I learn the innermost secrets of the around me, they reward me in many ways to keep quiet.

Men with pierced ears are better prepared for marriage. They've experienced pain and bought Jewellery.

Michael Dunn17-Oct-01 20:33

Michael Dunn

17-Oct-01 20:33

*scratches head* hmmm, so when you do nothing in WM_ERASEBKGND the flicker goes away?

--Mike--
http://home.inreach.com/mdunn/
"....." -- Silent Bob
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Christian Graus17-Oct-01 20:41

17-Oct-01 20:41

No, the flicker always remains. The buttons are owner drawn bitmap buttons and it's obvious when I have a lot that they are all being drawn grey and then the owner drawing code draws the bitmaps over them afterward, so the ones at the end of the list are noticably blank before each draw during the sizing process.

Christian

As I learn the innermost secrets of the around me, they reward me in many ways to keep quiet.

Men with pierced ears are better prepared for marriage. They've experienced pain and bought Jewellery.

overloaded insertion operator

Michael Dunn17-Oct-01 21:25

Michael Dunn

17-Oct-01 21:25

OK, so your WM_ERASEBKGND handler is out of the picture. Something is invalidating your buttons, maybe it's a WM_WINDOWPOSCHANGED, WM_SIZE, or similar handler in your button class?

--Mike--
http://home.inreach.com/mdunn/
"....." -- Silent Bob
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17-Oct-01 16:19

How would I use the overloaded insertion operator to input a string of a user defined class?

Re: overloaded insertion operator

kumar_p317-Oct-01 17:03

kumar_p3

17-Oct-01 17:03

istream& operator>>(istream& in)
{
//Write ur code
in>>string ;
// Some code
...
return in;
}

//Assuming that the fn is a member of the class.
if not then the following
if the class's name is 'A'
class A
{
..
friend istream& operator(istream& in, A &a) ;
..
};

istream& operator(istream& in, A &a)
{
...
}

Hope this helps

Variable argument lists

#realJSOP17-Oct-01 13:23

#realJSOP

17-Oct-01 13:23

I have a function which accepts a variable number of integer arguments like so:

void MyFunc(int nVal, ...);

I want to grab the first one, and pass the rest to a similarly defined function. How do I do that?

To hell with those thin-skinned pillow-biters. - Me, 10/03/2001

Re: Variable argument lists

Christian Graus17-Oct-01 16:26

Re: Variable argument lists

17-Oct-01 16:26

My understanding is if you use va_arg, va_start & va_end, one parameter is stripped from the list at a time as you parse them. If this is so, then you could strip the first one ( as you will obviously need to ) and then pass the resultant list along.

Of course, I could just be full of it....

Christian

As I learn the innermost secrets of the around me, they reward me in many ways to keep quiet.

Men with pierced ears are better prepared for marriage. They've experienced pain and bought Jewellery.

#realJSOP18-Oct-01 2:41

#realJSOP

18-Oct-01 2:41

I tried that. No workee.

Smile | :)

If I had the code I was playing with at work, I culd provide an example of what I've already tried.

Essentially, I passed 1,2,3,4,5 as parameters to the 1st function, used va_start to get the first parameter, and passed the list to the next function, and so on.

Func1 got 1 as the 1st param
Func2 got 2 as the first param
Func3 got 96 as the first param
Func4 got -20

By then I stopped because I knew something was seriously hosed up.

If I can't do this, I have to resort to passing a string or array of values.

To hell with those thin-skinned pillow-biters. - Me, 10/03/2001

Undeclared identifer message

Sam C17-Oct-01 12:29

Sam C

17-Oct-01 12:29

Hi,

Why does the following code generate a compile error of C2065 in VC 6++

//Beginning of function
CStdioFile myFile; <-Why do I have to do this to avoid the compile error C2065 (Undeclared identifier)

TRY
{
  CStdioFile myFile((LPCTSTR)m_FilePath, CFile::modeRead | CFile:: typeText);
}
CATCH (CFileException, err)
{
   MessageBox("Can't open file",...);
   //Other lines to set focus to another control
}
END_CATCH

//ASSERT(myFile.m_pStream!=NULL) <- Asserts here
Maui.File.SeekToBegin();  <-Asserts here due to Null reference

To get the asserts I had to put a variable declaration of CStdioFile myFile at the top of the function. This is because of the error I get with "Undelcared identifier". I don't get it isn't it already being declared in the TRY...CATCH block? And why is it when I make a forward declaration it still asserts at the following two lines after END_CATCH?

Really confused Confused | :confused:

Please help.

Sam C
----
Systems Manager
Hospitality Marketing Associates

Tomasz Sowinski17-Oct-01 12:33

Tomasz Sowinski

17-Oct-01 12:33

If you want to access myFile, it must be declared outside try/catch. And you should just use myFile in try/catch - currently you're creating another variable with identical name - and assert fires, because myFile visible outside of try/catch block is different than myFile you're playing with inside.

BTW: why don't you use plain try/catch instead of MFC macros?

Tomasz Sowinski -- http://www.shooltz.com

Sam C17-Oct-01 12:39

Sam C

17-Oct-01 12:39

At first I did have try catch set up the old fashioned way.

try
{
   CStdioFile myFile(...)
}
catch(CFileException *err)
{
   TRACE("PROBLEM OCCURED");
   err->Delete();
}

...

But I was thinking that may have been part of my problem Smile | :)

MFC confuses me (as you can already tell). So basically I have to go back and Declare it outside and call the OPEN member function from within the try/catch block.

Also is it bad to use MFC macros for MFC exceptions? I have never heard of a problem with this?

Thanks for your quick response.

Sam C
----
Systems Manager
Hospitality Marketing Associates

Fazlul Kabir17-Oct-01 12:36

Fazlul Kabir

17-Oct-01 12:36

This has something to do with "scope" of the TRY block, i.e. TRY{...}. It's fine to use the variable inside the scope, i.e. inside the braces, but not outside of it (which you were doing in your ASSERT statement).

Hope this helps.

// Fazlul

Get RadVC today! Play RAD in VC++
http://www.capitolsoft.com

Sam C17-Oct-01 12:42

Sam C

17-Oct-01 12:42

So if I only wanted to check basically the "OPEN" function of the class I have declared I have to encapsulate the rest of the code within the try block? So for example:

...
try
{
Open(...)
//Rest of fuctions and command
}
catch (...)
{
}

And I can't do this?

try
{
   Open(...);
}
Catch (...)
{
}

REST OF FUCTION CODE HERE USING CStdioFile

I find that peculiar and thanks for informing me of the try/catch scope, I did not know that it had it's own scope.

Sam C
----
Systems Manager
Hospitality Marketing Associates

Fazlul Kabir17-Oct-01 12:47

Fazlul Kabir

17-Oct-01 12:47

You're right. This scope thingy is related to braces and has nothing to do with TRY-CATCH. You can get similar error with the following code:

{
    int n = 0;
}
n = 5;

Hope this helps.

// Fazlul

Get RadVC today! Play RAD in VC++
http://www.capitolsoft.com

Converting ...

Hadi Rezaee17-Oct-01 12:23

17-Oct-01 12:23

How can i convert BMP file to JPEG file ?

My month article: Game programming by DirectX by Lan Mader.
Please visit in: www.geocities.com/hadi_rezaie/index.html

Hadi Rezaie

Christian Graus17-Oct-01 16:26

17-Oct-01 16:26

It's in the FAQ.

Christian

As I learn the innermost secrets of the around me, they reward me in many ways to keep quiet.

Men with pierced ears are better prepared for marriage. They've experienced pain and bought Jewellery.

Hadi Rezaee18-Oct-01 12:25

18-Oct-01 12:25

Hi,
Can you tell me, where is FAQ in this website ?
Please write URL address.

My month article: Game programming by DirectX by Lan Mader.
Please visit in: www.geocities.com/hadi_rezaie/index.html

Hadi Rezaie

Christian Graus18-Oct-01 12:28

18-Oct-01 12:28

The link is at the top of the lounge. There are three in a row, from memory - Demographics, Top 10 posters, Mike Dunn's C++ FAQ.

Christian

As I learn the innermost secrets of the around me, they reward me in many ways to keep quiet.

Men with pierced ears are better prepared for marriage. They've experienced pain and bought Jewellery.

Hadi Rezaee18-Oct-01 12:53

18-Oct-01 12:53

I found it ...
Thanks ...

My month article: Game programming by DirectX by Lan Mader.
Please visit in: www.geocities.com/hadi_rezaie/index.html

Hadi Rezaie

ADO question 1 ...

Hadi Rezaee17-Oct-01 12:20