Re: STL list / iterator question - C / C++ / MFC Discussion Boards

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Yes, it is possible

Jake Palmer24-Jul-01 7:42

Jake Palmer

24-Jul-01 7:42

Alright, I got that working Blush | :O

Sorry, and thanks anyway. Roll eyes | :rolleyes:

STL list / iterator question

24-Jul-01 6:57

I have a list class list<cmyclass> from which I have declared a typedef for the iterator. list<cmyclass>::iterator myIterator;

problem is, i cannot seem to cast myIterator to anything, not even to a variable of type CMyclass*. I need to cast the iterator to a DWORD so that I can store it in an MFC LVITEM struct for later use. I have no problem whatsoever if I use a vector instead of a list! I can happily cast away my vector iterator to a DWORD or LPARAM or even a CMyclass*.

Whats the deal? Cry | :((

Thanks in advance, BTW i am using VC 6.0 sp 5 and I have applied the latest dinkumware patches to my STL.

Re: STL list / iterator question

Not Active24-Jul-01 7:19

Not Active

24-Jul-01 7:19

I have used a STL list in the manner you discribe.

Perhaps a snippet of the code would allow us to see what you are doing and why it isn't working for you.

Re: STL list / iterator question

markkuk24-Jul-01 12:12

markkuk

24-Jul-01 12:12

Vector iterators are often ordinary pointers, but you can't trust on that. There's absolutely no guarantee that an iterator will fit in a DWORD or a void*.

Re: STL list / iterator question

25-Jul-01 4:48

The *address* of the iterator should fit nicely into a DWORD, or for that matter a void*. Of course, you have to cast away the type.

Re: STL list / iterator question

Joaquín M López Muñoz24-Jul-01 12:51

Joaquín M López Muñoz

24-Jul-01 12:51

you can follow this scheme:

* use vector instead of list
* store the index instead of an iterator (this will fit in a DWORD)
* add a constructor to myIterator taking as argument the index, like this

myIterator(DWORD index):
  list::iterator(begin()+index)
{}

I hope you get the point, just fill in the details. Good luck

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: STL list / iterator question

25-Jul-01 4:47

Thanks but this approach will not work for me. I am currently using a vector and I need to use a list instead. Primarily because I am deleting and inserting (and moving) elements of my container. Iterators become invalid in a vector if you insert anywhere but the end. A list will meet my needs, If I can find a way to store the address of the iterator in my LVITEM struct.

Re: STL list / iterator question

CodeGuy25-Jul-01 5:50

CodeGuy

25-Jul-01 5:50

If you have a vector<t>, then a derefenced vector<t>::iterator is T.

BUT ...
If you have a list<t>, then a dereferenced list<t>::iterator is not T, but rather an object that would look like the following:
class ListNode
{
T* pNextObj;
T data;
...
}

So this is a safety thing on the part of the list implementors to keep you straight -- if you casted to change type, you could not get back the original object again (because this is internal to each STL implementation).

However, given the following code, this would work:
list<int> l;
l.push_back(1);
DWORD dw = (DWORD)(&l.begin());

Then if I want to print the list entry,
typedef list<int>::iterator ListIntIter;
ListIntIter* pi = (ListIntIter*)dw;
cout << **pi << endl;

Alternatively, you can store the index of the iterator and then use STL's 'advance' algorithm.

One more note: I actually consider all of this slightly dangerous, because while you can hold an address to a list element, remember that the size and order of the list could change if you are performing other list operations in the meantime. If you are holding onto iterators because you always want to keep track of, say, the 3rd element, then remember that although the iterator itself will not change in a list, its overall position in the list may still shift. In this case, if you are always wanting the nth element, I would use 'advance' or switch back to a random access container like vector or deque.

Opening a window in a console application

Adi Shavit24-Jul-01 6:54

Adi Shavit

24-Jul-01 6:54

Hi,

I'm trying to open a dialog window in a console application (Using MFC in a shared DLL).
I'm just interested in window to draw on. No dialog items and so on.
Also, I cannot use resources as this will be a utility class for displaying images in console applications.
Using some old code as reference, I managed to do it in a C-style win32 way using a messgage handler with switch/case and threads and using DialogBoxIndirectParam().

I was wondering how I can do it in a more OO way using CWnd message handler mapping, to automatically handle any drwing or other window events.

How do I get the window to show? How do I initialize it?

Thanks a lot,
Adi

PS,

While on the subject, if I have a class with resources.
How can I use this class (as a linked library) in other application, without manually adding its resources to the new project?

Thanks.

How do I add a custom mimize button?

Tommy H D Svensson24-Jul-01 6:27

Tommy H D Svensson

24-Jul-01 6:27

Hi everone,

Can I override some function(s) to customize the minimize button, that is the WM_MINIMIZEBOX?

Is it also possible to add a new button in the title bar?

Re: How do I add a custom mimize button?

Tomasz Sowinski24-Jul-01 7:37

Tomasz Sowinski

24-Jul-01 7:37

You'll have to handle WM_NCPAINT. DrawFrameControl can help in button drawing. This was discussed once in MSJ, search your VC++ help for ShadeCap.

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

TransparentBlt , Win95 ( not supported + problems )

Leon24-Jul-01 6:25

Leon

24-Jul-01 6:25

Hi ,

As far as I understand function TransparentBlt isn't supported in Win95
and some versions of NT. Not just that : it needs msimg32.dll and as I've
heard causes some memory and resources related problems.

What I need is function

BOOL MyTransparentBlt (
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
);

That will work under Win95 and won't cause problems. I need
just this only function ( source ) - don't want to deal
with "msimg32.dll"

I'll appreciate Your help,
Thank You Smile | :)

Re: TransparentBlt , Win95 ( not supported + problems )

24-Jul-01 10:32

This is what U need
void MyTransparentBlt( HDC hdcDest, int nXDest, int nYDest, int nWidth,
int nHeight, HDC hBmpDC/*, HBITMAP hBitmap*/, int nXSrc, int nYSrc,
COLORREF colorTransparent, HPALETTE hPal)
{
HDC hdcMask = ::CreateCompatibleDC( hdcDest );
HDC hdcTmp = ::CreateCompatibleDC( hdcDest );
HBITMAP bmMask = ::CreateBitmap( nWidth, nHeight, 1, 1, NULL );
HBITMAP hOldMaskBitmap = (HBITMAP)::SelectObject( hdcMask, bmMask );
HBITMAP hTmpBmp = CreateCompatibleBitmap(hdcDest, nWidth, nHeight);
HBITMAP hOldTmpBmp = (HBITMAP)::SelectObject(hdcTmp, hTmpBmp);

::BitBlt(hdcTmp, 0,0,nWidth, nHeight, hBmpDC, nXSrc, nYSrc, SRCCOPY );

::SetBkColor( hdcTmp, colorTransparent );

::SetTextColor( hBmpDC, RGB( 0, 0, 0 ) );
::BitBlt( hdcMask, 0, 0, nWidth, nHeight, hdcTmp, 0, 0, SRCCOPY );
HDC hdcOffScr = ::CreateCompatibleDC(hdcDest);
::SetBkMode(hdcOffScr, TRANSPARENT);
HBITMAP hbmOffScr = ::CreateBitmap(nWidth, nHeight,
(BYTE)GetDeviceCaps(hdcDest, PLANES),
(BYTE)GetDeviceCaps(hdcDest, BITSPIXEL),
NULL);
HBITMAP hbmOldOffScr = (HBITMAP)::SelectObject(hdcOffScr, hbmOffScr);
::BitBlt(hdcOffScr, 0, 0, nWidth, nHeight, hdcDest, nXDest, nYDest, SRCCOPY);
::SetBkColor( hBmpDC, RGB( 0, 0, 0 ) );
::SetTextColor( hBmpDC, RGB( 0xff, 0xff, 0xff ));
COLORREF crOldBackColor = ::GetBkColor( hdcDest );
COLORREF crOldTextColor = ::GetTextColor( hdcDest );
::SetBkColor( hdcOffScr, RGB( 0xff, 0xff, 0xff ) );
::SetTextColor( hdcOffScr, RGB( 0, 0, 0 ) );
::BitBlt( hdcOffScr, 0, 0, nWidth, nHeight, hBmpDC, 0, 0, SRCINVERT );
::BitBlt( hdcOffScr, 0, 0, nWidth, nHeight, hdcMask, 0, 0, SRCAND );
::BitBlt( hdcOffScr, 0, 0, nWidth, nHeight, hBmpDC, 0, 0, SRCINVERT );
::SetBkColor( hdcOffScr, crOldBackColor );
::SetTextColor( hdcOffScr, crOldTextColor );
::SetBkMode(hdcDest, TRANSPARENT);

::BitBlt(hdcDest, nXDest, nYDest, nWidth, nHeight, hdcOffScr, 0, 0, SRCCOPY);
if ( hOldMaskBitmap )
::SelectObject( hdcMask, hOldMaskBitmap );
if ( hbmOldOffScr )
::SelectObject( hdcOffScr, hbmOldOffScr );
if ( hOldTmpBmp )
::SelectObject( hdcTmp, hOldTmpBmp );

::DeleteObject( hTmpBmp );
::DeleteObject( bmMask );
::DeleteObject( hbmOffScr );
::DeleteDC( hdcOffScr );
::DeleteDC( hdcTmp );

::DeleteDC( hdcMask );
}

but with more effort you could do your self(msdn etc), like I did it is a lot more fun !!

good luck,
Dror

Re: TransparentBlt , Win95 ( not supported + problems )

Christian Graus24-Jul-01 13:04

Christian Graus

24-Jul-01 13:04

I've not tested the code someone else just offered, but I notice it failed to allow for a differering source and destination size. I don't even have the code here, but the Sept issue of WDJ will have an article from me on doing exactly what you want, and also alphablend under W95. Basically to change the code below you just need to do a stretchblt to change the source bitmap to the dimensions of the destination.

Christian

#include "std_disclaimer.h"

The careful application of terror is also a form of communication.

Eagles may soar, but weasels don't get sucked into jet engines.

What would be magical about the Control ID of a radio Button?

tm24-Jul-01 6:09

24-Jul-01 6:09

It seems that when I dynamically create my radio button (i.e at run time) the text gets displayed if I choose certain UID number and not the other ones.
m_RadioButtonArray[nDex].Create("paradi",
WS_GROUP | WS_VISIBLE | WS_CHILD | BS_AUTORADIOBUTTON , ctrlRect,this, 2013 );

Note that on this screen I am also dynamically creating other edit controls that their GUI ID ranges from 1999 to 2011 !!!!

Paradise is where I am.
Voltaire

converting decimal to hexadecimal

24-Jul-01 6:07

anyone knows how to convert an int variable from decimal to hex?? I am using VC++ and MFC, but am looking for a simple function to do it.
please reply to me at asengupt@uiuc.edu
Thanks!
ananya
(student)

Re: converting decimal to hexadecimal

Not Active24-Jul-01 7:24

Not Active

24-Jul-01 7:24

If you want to print it use something like printf, or use _ltoa or _ultoa.

Dialog problem

24-Jul-01 5:56

i've created a Dialog app using the MFC wizard. now, i want to add to the dialog a tool-bar and a status-bar. so i added this code to onInitDialog():

UINT indicators [3] =
{
ID_PAN1,
ID_PAN2,
ID_PAN3
};

if (!m_status.Create(this))
{
TRACE0("Failed to create toolbar\n");
return -1; // fail to create
}
m_status.SetIndicators(indicators, 3);

if (!toolbar.Create(this, TBSTYLE_FLAT, WS_CHILD | WS_VISIBLE | CBRS_TOP
| CBRS_GRIPPER | CBRS_TOOLTIPS | CBRS_FLYBY | CBRS_SIZE_DYNAMIC) ||
!toolbar.LoadToolBar(IDR_TOOLBAR1))
{
TRACE0("Failed to create toolbar\n");
return -1; // fail to create
}

i think its ok, but when i execute the app, i dont see neither the statusbar nor the toolbar

Pliz jelp. thanks

Re: Dialog problem

24-Jul-01 7:27

MFC sample DLGCBAR32 does exactly that.

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

this sample doesnf help me!

24-Jul-01 10:55

another idea?

Re: this sample doesnf help me!

Carlos Antollini24-Jul-01 11:10

Carlos Antollini

24-Jul-01 11:10

Why the sample don't help?
The sample that said Tomasz is very good.
Try to explain that you don't understand....
Regards

Carlos Antollini.

ID??

24-Jul-01 5:12

hi

almost every control has a parameter ID in its Create() function...(CButton for example)

what is that parameter and what should i pass to the function?
i've tried to put any number and it worlks, but it looks wrong to me

thanks

Re: ID??

Christian Graus24-Jul-01 13:06

Christian Graus

24-Jul-01 13:06

The ID is defined in resource.h and then passed in by name. This is so there is no double up, where two controls have the same ID.

Christian

#include "std_disclaimer.h"

The careful application of terror is also a form of communication.

Eagles may soar, but weasels don't get sucked into jet engines.

Serialize : How can I know if the loading from the file success ???

24-Jul-01 5:04

I want to use in serialize and CArchive for save and load from file
But I don't know how can I check if the loading success ?
Who can help me ? Confused | :confused:

Re: Serialize : How can I know if the loading from the file success ???

C~~MFC6.0~~VS.NETUser24-Jul-01 5:20

C~~MFC6.0~~VS.NETUser

24-Jul-01 5:20

Try using...

if(ArchiveObj.isLoading())
{
     //do if CArchive::isLoading() returns true
     //Loading Data...
}
else
{
     //do if CArchive::isLoading() returns false
     //Storing Data...
}

Hope it works...

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