Re: Setting string variables - C / C++ / MFC Discussion Boards

act_x3-Jun-03 8:52

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

Edit box

will13833-Jun-03 6:12

will1383

3-Jun-03 6:12

I'm currently making something similar to a telnet-type window and I'm using a multi-line edit box to display the information I need.

My question is this:

I need the edit box to scroll, to I'm using the ES_AUTOVSCROLL style. Only thing is, I need to set the number of visible lines based on the window size in order for the scrolling to work automatically. I have not been able to find any information on how to set the max number of lines in a multi-line edit box. Does anyone know how to do this?

Any comments or suggestions are greatly appreciated.

Thanks!

Re: Edit box

valikac3-Jun-03 7:45

valikac

3-Jun-03 7:45

Why does the design utilize an editbox and not an editview?

Kuphryn

Re: Edit box

will13833-Jun-03 8:48

will1383

3-Jun-03 8:48

Becuase I'm not using MFC Frown | :(

Stuck with what i got. Is there and edit view that's usable without mfc? I'm looking now.

Re: Edit box

basementman9-Jun-03 6:27

basementman

9-Jun-03 6:27

Just create the edit control of a size that fits the number of lines that you wish to display. Then, make sure that the ES_AUTOVSCROLL style is set. Problem solved. You also may want to set a fixed-pitch font and handle the background color to make it appear like a console window.

Updating window when drawing

Rage3-Jun-03 6:09

Rage

3-Jun-03 6:09

In my MDI app, I'm trying to draw an ellipse in my CView (In OnDraw() more exactly), but my view does not get updated unless I move or scroll or does something ot the window. Invalidate() and RedrawWindow() just make my app loop, since they call OnDraw which ... you know Big Grin | :-D

so how do you get the view updated once something has been put in the pDC ? Confused | :confused:

Thanks...

~RaGE();

Re: Updating window when drawing

valikac3-Jun-03 7:48

valikac

3-Jun-03 7:48

Try other updating CWnd member functions including UpdateWindow().

Kuphryn

Re: Updating window when drawing

Maximilien3-Jun-03 8:05

Maximilien

3-Jun-03 8:05

well, if I understood correctly, he tried putting those in the OnDraw which will callback the OnDraw and will crash the software ...

The problem (I think) is that he draws in the OnDraw, but issues the drawing somewhere else (ie. from a menu or the mouse handler) which might not Invalidat the view, and will not draw.

Maximilien Lincourt
For success one must aquire one's self

Multimedia timers

act_x3-Jun-03 5:31

act_x

3-Jun-03 5:31

I wanted to use the Multimedia timers and have implemented based on reference in the MSDN site
I Included mmsytem.h

still i get the following linker errors

Linking...<br />
error LNK2001: unresolved external symbol __imp__timeSetEvent@20<br />
error LNK2001: unresolved external symbol __imp__timeBeginPeriod@4 error LNK2001: unresolved external symbol __imp__timeGetDevCaps@8

I was unable to figure out the problem !

Re: Multimedia timers

Rage3-Jun-03 5:40

Rage

3-Jun-03 5:40

Did you add winmm.lib to the library your are linking to ?

~RaGE();

Re: Multimedia timers

act_x3-Jun-03 5:57

act_x

3-Jun-03 5:57

thanks

Interprocess communication

doctorpi3-Jun-03 5:13

doctorpi

3-Jun-03 5:13

Hi guys
I'm trying to implement a solution to communicate 2 app through a global system message
In the app1 I do in InitInstance

msgApp=RegisterWindowMessage("DATABASE_UPDATED");

and then when is necessary I do

PostMessage(theApp.msgApp,1,1) wParam and lParam it doesn't matter.

What I have to write to manage DATABASE_UPDATE message in app2 and where?

Both app are SDI app.
Best Regards
Dr. Pi

Re: Interprocess communication

Rage3-Jun-03 5:24

Rage

3-Jun-03 5:24

With MFC :

With a simple message (#define MYMESSAGE WM_USER+1) :

Go into the your MainFrame.cpp, and add :

BEGIN_MESSAGE_MAP(CMainFrame, CFrameWnd)
	//{{AFX_MSG_MAP(CMainFrame)
	ON_WM_CREATE()
	ON_WM_SIZE()
        ON_MESSAGE(MYMESSAGE,memberFxn)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

Prototype , in MainFrame.cpp :

// Generated message map functions
protected:
//{{AFX_MSG(CMainFrame)
afx_msg LRESULT memberFxn(WPARAM, LPARAM);
//}}AFX_MSG
DECLARE_MESSAGE_MAP()

With registered message :

Same with :

ON_REGISTERED_MESSAGE( msgApp, memberFxn )

and

afx_msg LRESULT memberFxn(WPARAM, LPARAM);

~RaGE();

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.