C / C++ / MFC Discussion Boards

Re: CImage::StretchBlt does not work!?

schaereran@gmx.net5-Jun-03 0:36

schaereran@gmx.net

5-Jun-03 0:36

very cool! now it works! thanx a lot!

How do i create a random number?

Redeemer-dk3-Jun-03 9:36

Redeemer-dk

3-Jun-03 9:36

Is there a function for retreiving a random integer lying in the range from one integer to another? I'm using Win32...

THanks in advance.

Re: How do i create a random number?

C^hris L^osinger3-Jun-03 9:53

C^hris L^osinger

3-Jun-03 9:53

see rand() and srand(..)

srand(-1);
int v = (rand() % (low + high)) + low;

To vote with no response is to follow the way of the coward.

Re: How do i create a random number?

Dean Goodman3-Jun-03 11:38

Dean Goodman

3-Jun-03 11:38

Check out this page -- shows a better way to get your random numbers. When you use modular arithmetic, you focus on the low-order bits that aren't as "random" as the high-order ones.

The page shows many examples of how to get a random number (int or floating point) in a given range.

--Dean

Re: How do i create a random number?

David Crow3-Jun-03 10:21

David Crow

3-Jun-03 10:21

No, but you can get a pseudo-random number with srand() and rand().

Re: How do i create a random number?

RedZenBird3-Jun-03 10:49

RedZenBird

3-Jun-03 10:49

See article by:

Stephen K. Park and Keith W. Miller.
RANDOM NUMBER GENERATORS: GOOD ONES ARE HARD TO FIND.
Communications of the ACM, New York, NY.,October 1988 p.1192

Just trying to keep the forces of entropy at bay

Re: How do i create a random number?

Anders Molin3-Jun-03 12:14

Anders Molin

3-Jun-03 12:14

#define GetRandom(min, max) ((rand() % (int)(((max) + 1) - (min))) + (min)) //get a random number between min and max

Remember something like srand(GetTickCount()); first...

- Anders

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

EnableMenuItem does not work

Shay Harel3-Jun-03 9:25

Shay Harel

3-Jun-03 9:25

I have an application with a menu that I want to disable one command in it.

I write:

<br />
CMenu *pmenu;<br />
pmenu=CMaimFrame::GetMenu();<br />
pMenu->EnableMenuItem (ID_FILE_OPEN,MF_BYCOMMAND|MF_GRAYED);<br />

But the item will not go gray !!!

Shay

Re: EnableMenuItem does not work

valikac3-Jun-03 9:34

valikac

3-Jun-03 9:34

Include MF_DISABLED. See if that does it.

EnableMenuItem (ID_FILE_OPEN, MF_BYPOSITION|MF_DISABLED|MF_GRAYED)

Kuphryn

Re: EnableMenuItem does not work

Shay Harel3-Jun-03 9:48

Shay Harel

3-Jun-03 9:48

Not working.
I have a strange feeling that it's not pointing to my menu,
If I type

<br />
CMeny *pmenu=GetMenu();<br />
pmenu->DestroyMenu();<br />

Nothing happened .....

Re: EnableMenuItem does not work

Mike Upton4-Jun-03 0:22

Mike Upton

4-Jun-03 0:22

Since you're using an MFC app, you should probably be using command update handlers to deal with enabling/disabling menu items.

See Mike Dunn's C++ FAQ section 7.1[^] for more information.

"We are the knights who say Ni" _{(The Knights Who Say Ni)}

activex including a dll/lib

Anonymous3-Jun-03 9:10

Anonymous

3-Jun-03 9:10

Hi all

I am trying to create an activeX control which includes a dll.

At the linking stage of compilation, it gives a dllmain already defined.

exact error is:
Linking...
mfcs42.lib(dllmodul.obj) : error LNK2005: _DllMain@12 already defined in MSVCRT.lib(dllmain.obj)
mfcs42.lib(dllmodul.obj) : warning LNK4006: _DllMain@12 already defined in MSVCRT.lib(dllmain.obj); second definition ignored
Creating library Release/ShpEditAFX.lib and object Release/ShpEditAFX.exp
Release/ShpEditAFX.ocx : fatal error LNK1169: one or more multiply defined symbols found

Can anyone help me with it please? I appreciate your help.

Thanks
Yogi

Event like CEvent

act_x3-Jun-03 8:52

act_x

3-Jun-03 8:52

Hi
I needed the functionality for the CEvent object in MFC . I am working in a non MFC environment and needed a similar synchronization object.
Basically I want to have a request , Wait and response type of mechanism .

I want to be able to use the WaitforSingleObject call to wait for a duration on a event object .

How do I go about it. Is there a non MFC event class or object available ?

Re: Event like CEvent

Anonymous3-Jun-03 9:14

Anonymous

3-Jun-03 9:14

You can use a HANDLE, in conjunction with the API Calls, ::CreateEvent(), ::ResetEvent(), ::SetEvent(). Close it with a call to ::CloseHandle().

Re: Event like CEvent

Peter Weyzen3-Jun-03 11:54

Peter Weyzen

3-Jun-03 11:54

you can always write your own, or do something like this -- which is pretty close to what I use:

<br />
class MyEvent <br />
{<br />
  HANDLE m_EventHandle;<br />
<br />
public:<br />
  MyEvent( BOOL ManualReset = TRUE, BOOL InitialState = FALSE, LPCSTR Name = NULL )<br />
  {<br />
    m_EventHandle = CreateEvent( NULL, ManualReset, InitialState, Name );<br />
  }<br />
<br />
  virtual ~MyEvent()<br />
  {<br />
    CloseHandle( m_EventHandle );<br />
  }<br />
<br />
  HANDLE GetHandle()<br />
  {<br />
    return m_EventHandle;<br />
  }<br />
<br />
  BOOL Wait( DWORD Time = INFINITE )<br />
  {<br />
    return WaitForSingleObject( GetHandle(), Time ) != WAIT_TIMEOUT;<br />
  }<br />
 <br />
  void Reset()<br />
  {<br />
    ResetEvent( GetHandle() )<br />
  }<br />
<br />
  void Set()<br />
  {<br />
    SetEvent( GetHandle() );<br />
  }<br />
<br />
  BOOL IsSet()<br />
  {<br />
    return (WaitForSingleObject( GetHandle(), 0 ) != WAIT_TIMEOUT );<br />
  }<br />
};<br />

How's that?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br />
Peter Weyzen<br />
Staff Engineer<br />
Santa Cruz Networks

Error in Subclass ......help me

_skidrow_vn_3-Jun-03 8:24

_skidrow_vn_

3-Jun-03 8:24

My problem only shows in Windows98SE not in WindowsXPpro (I tested it both in 98SE and XPpro)
When i compile this code in Windows98SE by VC6
it's okay but when I debug >> F5
It shows Error Message look like this

First-chance exception in SkidRow2.exe (GDI32.DLL): 0xC0000005: Access Violation.

Whenever SubclassButtonProc is called, that Err msg show again....... more and more
finally, graphic interface of my Button is disorder
This error cause my code but I dont know how to fix it........ I dont know where is it? where the error in my code?
could you help me to find it
thank you

MyProject(65KB)
=========================================================

<br />
//////////////////////////////////////////////////////////////////////////////////////////<br />
// GetWindowRect() => left,top,right,bottom tinh theo he toa do cua SCREEN<br />
// GetClientRect() => luon cho ra ket qua 0,0,width,height<br />
//////////////////////////////////////////////////////////////////////////////////////////<br />
LRESULT CALLBACK SubclassButtonProc(HWND hWndButton, UINT Msg, WPARAM wParam, LPARAM lParam)<br />
{<br />
	//return 0;<br />
<br />
	static INT	fLButtonDown;<br />
	static INT	fMouseIn;<br />
	static INT	fDrawMouseOut;<br />
	HDC			hDC;<br />
<br />
	RECT		rect;	<br />
	POINT		pt;<br />
<br />
	GetCursorPos(&pt);<br />
	GetWindowRect(hWndButton, &rect);	<br />
<br />
	switch(Msg)<br />
	{<br />
		case WM_LBUTTONDBLCLK:		<br />
			fMouseIn=1;						<br />
			goto Work;<br />
		case WM_MOUSEMOVE:<br />
			// dang SetCapture()<br />
			if (!PtInRect(&rect,pt))<br />
			{<br />
				fMouseIn=0;<br />
				<br />
				if (!fDrawMouseOut)<br />
				{<br />
					InvalidateRect(hWndButton, NULL, TRUE);<br />
					fDrawMouseOut=1;<br />
				}<br />
				return FALSE;<br />
			}<br />
			else<br />
				fDrawMouseOut=0;<br />
				<br />
			<br />
			// khong bi SetCapture()<br />
			if (!fMouseIn)<br />
			{	<br />
				<br />
				fMouseIn=1;<br />
				InvalidateRect(hWndButton, NULL, TRUE);<br />
//*				<br />
				TRACKMOUSEEVENT tme;<br />
				tme.cbSize		=sizeof(tme);<br />
				tme.dwFlags		=TME_LEAVE;<br />
				tme.dwHoverTime	=HOVER_DEFAULT;<br />
				tme.hwndTrack	=hWndButton;<br />
				_TrackMouseEvent(&tme);<br />
//*/<br />
				return FALSE;<br />
			}<br />
			return FALSE;<br />
		case WM_MOUSELEAVE:					<br />
			if(fMouseIn) <br />
			{<br />
				fMouseIn=0;				<br />
<br />
				InvalidateRect(hWndButton, NULL, TRUE);<br />
				return FALSE;<br />
			}<br />
			InvalidateRect(hWndButton, NULL, TRUE);<br />
			return FALSE;<br />
Work:<br />
		case WM_LBUTTONDOWN:<br />
			SetCapture(hWndButton);<br />
///*<br />
			{<br />
				HDC hdc;<br />
				CHAR buffer[100];<br />
				static i;<br />
				hdc=GetDC(hWnd);<br />
				i++;<br />
				sprintf(buffer,"down %d time(s)",i);<br />
				TextOut(hdc,0,60,buffer, strlen(buffer));<br />
				ReleaseDC(hWnd,hdc);<br />
			}<br />
//*/<br />
			fLButtonDown=1;<br />
			InvalidateRect(hWndButton, NULL, TRUE);<br />
			return FALSE;<br />
		<br />
		case WM_LBUTTONUP:<br />
			{	<br />
				HDC hdc;<br />
				CHAR buffer[100];<br />
				static i;<br />
				hdc=GetDC(hWnd);<br />
				i++;<br />
<br />
				if (!PtInRect(&rect,pt))<br />
				{<br />
					sprintf(buffer,"up %d time(s) --- x=%d y=%d out left=%d top=%d right=%d bottom=%d"<br />
					,i,pt.x,pt.y,rect.left,rect.top,rect.right,rect.bottom);<br />
					fLButtonDown=0;<br />
					ReleaseCapture();<br />
					return FALSE;<br />
				}<br />
				else<br />
				{<br />
					sprintf(buffer,"up %d time(s) --- x=%d y=%d in left=%d top=%d right=%d bottom=%d"<br />
					,i,pt.x,pt.y,rect.left,rect.top,rect.right,rect.bottom);<br />
				}<br />
<br />
<br />
				TextOut(hdc,0,90,buffer, strlen(buffer));<br />
				ReleaseDC(hWnd,hdc);<br />
			}<br />
			fLButtonDown=0;			<br />
			ReleaseCapture();<br />
			InvalidateRect(hWndButton, NULL, TRUE);<br />
	<br />
			// user push button<br />
			if (TRUE)			<br />
			{<br />
				//////////////////////////////////////////////////////<br />
				//TO DO: EVENT, WHAT USER WANT WHEN CLICK BUTTON<br />
				//////////////////////////////////////////////////////<br />
				//MessageBox(NULL,"EVENT","",MB_OK);<br />
				HDC hdc;<br />
				CHAR buffer[100];<br />
				static i;<br />
				hdc=GetDC(hWnd);<br />
				i++;<br />
				sprintf(buffer,"push %d time(s)",i);<br />
				TextOut(hdc,0,0,buffer, strlen(buffer));<br />
				ReleaseDC(hWnd,hdc);<br />
			}				<br />
			return FALSE;<br />
		case WM_PAINT:<br />
			/////////////////////////////////////////////////////////////			<br />
			// WM_PAINT hanlder<br />
			// WM_MOUSELMOVE, WM_MOUSELEAVE inform ------> <br />
			// WM_PAINT handler process these notify messages<br />
			// InvaliateRect(), BeginPaint().....<br />
			/////////////////////////////////////////////////////////////<br />
			INT			SaveBkMode;<br />
			COLORREF	SaveTextColor;					<br />
			HDC			hMemDC;<br />
			HFONT		hSaveFont;<br />
			HBITMAP		hbmImage, hbmSave;<br />
			CHAR		szCaption[30];<br />
			CHAR		cIndex;<br />
			WORD		xImage, yImage, xText, yText;<br />
			SIZE		size;<br />
			PAINTSTRUCT	ps;<br />
			RECT		rect;	<br />
<br />
			GetClientRect(hWndButton, &rect);	// use GetWindowRect >> NO RESULT<br />
			hDC=BeginPaint(hWndButton, &ps);<br />
<br />
				HDC hdc;<br />
				CHAR buffer[100];<br />
				static i;<br />
				hdc=GetDC(hWnd);<br />
				i++;<br />
				sprintf(buffer,"redraw %d time(s)",i);<br />
				TextOut(hdc,0,30,buffer, strlen(buffer));<br />
				ReleaseDC(hWnd,hdc);<br />
<br />
			hSaveFont=(HFONT)SelectObject(hDC, hFontCaption);<br />
			GetWindowText(hWndButton, szCaption, strlen(szCaption));<br />
			hbmImage=LoadBitmap(hInst, MAKEINTRESOURCE(IDB_BITMAP1));<br />
			<br />
			cIndex=0;<br />
			<br />
			hMemDC=CreateCompatibleDC(NULL);<br />
<br />
			BITMAP bm;<br />
			GetObject(hbmImage, sizeof(bm), &bm);<br />
			<br />
			GetTextExtentPoint32(hDC, szCaption, lstrlen(szCaption), &size); <br />
			xImage=rect.left+((rect.right-rect.left)-(bm.bmWidth + size.cx +4))/2;<br />
			yImage=rect.top+((rect.bottom-rect.top)-bm.bmHeight)/2;<br />
			xText=xImage+bm.bmWidth+4;<br />
			yText=rect.top+((rect.bottom-rect.top)-size.cy)/2;<br />
			SaveBkMode=SetBkMode(hDC, TRANSPARENT);<br />
			SaveTextColor=SetTextColor(hDC, RGB(0,0,0));<br />
			<br />
			hbmSave=(HBITMAP)SelectObject(hMemDC, hbmImage);<br />
			if (!fMouseIn)		// mouse out button<br />
			{<br />
				WINDOW::DrawGradientRect(hDC, rect, WCOLOR1, WCOLOR3, 0);<br />
				TransparentBlt(hDC, xImage,yImage,bm.bmWidth, bm.bmHeight, hMemDC, 0,0, bm.bmWidth, bm.bmHeight,RGB(255,255,255));<br />
				TextOut(hDC, xText, yText, szCaption, strlen(szCaption));<br />
			}<br />
			else				// mouse in button<br />
			{<br />
				WINDOW::DrawGradientRect(hDC, rect, WCOLOR1,WCOLOR2, 0);<br />
				TransparentBlt(hDC, xImage,yImage,bm.bmWidth, bm.bmHeight, hMemDC, 0,0, bm.bmWidth, bm.bmHeight,RGB(255,255,255));<br />
				TextOut(hDC, xText, yText, szCaption, strlen(szCaption));<br />
			}<br />
<br />
			// push button slowly then OKAY<br />
			// push button quickly then ERROR, ???????????????????????			<br />
			if (fLButtonDown && fMouseIn)	// Lbutton down<br />
			{<br />
				// redraw Background<br />
				WINDOW::DrawGradientRect(hDC, rect, WCOLOR1, WCOLOR2, 0);<br />
				rect.left	+=2;<br />
				rect.top	+=2;				<br />
				TransparentBlt(hDC, xImage+2, yImage+2,bm.bmWidth, bm.bmHeight, hMemDC, 0,0, bm.bmWidth, bm.bmHeight,RGB(255,255,255));<br />
				TextOut(hDC, xText+2, yText+2, szCaption, strlen(szCaption));<br />
				rect.left	-=2;<br />
				rect.top	-=2;				<br />
<br />
				DrawEdge(hDC, &rect, EDGE_SUNKEN, BF_RECT);	<br />
			}<br />
			else				// Lbutton up<br />
			{<br />
				DrawEdge(hDC, &rect, EDGE_RAISED, BF_RECT);	<br />
			}<br />
<br />
			// free all<br />
			SetTextColor(hDC, SaveTextColor);<br />
			SetBkMode(hDC, SaveBkMode);<br />
			SelectObject(hMemDC, hbmSave);<br />
			DeleteDC(hMemDC);<br />
			SelectObject(hDC, hSaveFont);<br />
			DeleteObject(hSaveFont);<br />
			DeleteObject(hbmSave);			<br />
			EndPaint(hWndButton, &ps);<br />
			return TRUE;<br />
		default: <br />
			return CallWindowProc(OriButtonProc, hWndButton, Msg, wParam, lParam);			<br />
	}	<br />
}

proper format of ,,for loop in C++.NET

mr20033-Jun-03 7:57

mr2003

3-Jun-03 7:57

Hi,
I would like to know what is the proper format of a for-loop is in VC++.NET

Ehsan Behboudi

Re: proper format of ,,for loop in C++.NET

Maximilien3-Jun-03 8:03

Maximilien

3-Jun-03 8:03

I think that the variable definition in the for statement will local to the for body.
(saw this in a post here not too long ago )

for ( int i = 0; i<100; i++ )
{
 // do something.
}

or are you talking about something different ?

Maximilien Lincourt
For success one must aquire one's self

Setting string variables

beginningStudent3-Jun-03 6:43

beginningStudent

3-Jun-03 6:43

Please help beginning student. How do you set variables of type char or of type string such that they can be used in an If/Then Statement and While loop? I have tried declaring the variables as a string

#include <iostream.h>
#include <string>

void newLine();
void main()
{string firstName, lastName, recordName;
}

and I get an error.

Thanks for your help. Smile | :)

Re: Setting string variables

valikac3-Jun-03 7:43

valikac

3-Jun-03 7:43

Make sure you have included the right header.

#include <string>
using std::string;

Kuphryn

Re: Setting string variables

Anonymous3-Jun-03 7:45

Anonymous

3-Jun-03 7:45

I use character arrays, I've never used string types before.

To set a string you can use strcpy(), or can initialize it like
char szFirstName[30] = "SavageKen";

Re: Setting string variables

jhwurmbach3-Jun-03 8:13

jhwurmbach

3-Jun-03 8:13

After making sure you did
#include < string >
you need to make sure to access them with std::string,
or you can use
using std::string;
and from then on simply write string, or as a third (closly related) possibility you can add
using namespace std;
and omit writing any std:: at the expense of some rare problems with names used twice.

My opinions may have changed, but not the fact that I am right.

Splitter

sulaxan3-Jun-03 6:32

sulaxan

3-Jun-03 6:32

my requirement is....... to have 'T' shape splitter windows..........
>
> like this......
>
> -------------------
> | | |
> | 1st | 2nd |
> | view | view |
> |------------------
> | 3rd |
> | View |
> -------------------
>
> that's the look it shud look like........
>
> i'll have Tree control in 1st view.
> i've to replace the 2nd view based on selection of the branch items in
tree
> control......
>
> 3rd view is constant...... only 2nd view is dynamic......
> m trying different options..... but failed to reach the destination so
> far.....
> if u 've some class for splitter to do like this.... can u plz. send
> me......
>
> thanks and regards
> Adi Narayana

Re: Splitter

Anonymous3-Jun-03 10:47

Anonymous

3-Jun-03 10:47

See if you can use this framework

http://www.codeproject.com/dialog/visualfx.asp

Re: Splitter

sulaxan3-Jun-03 18:46

sulaxan

3-Jun-03 18:46

thanks yaar..... for immediate reply.....

i m working on it now..... hope it'll work for me ...

regards
Adi

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