C / C++ / MFC

Re: Extract information from a List class (Win32 API question)

7-Nov-06 2:49

Leprechaun78 wrote:
...the ListBox class.

Where is this class defined? How would WindowDump even know that an application was usng such a class, let alone have access to it?

Leprechaun78 wrote:
...the class (List), handle, process, styles etc.

I've not heard of a class having a handle and a style. These sound like window properties.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Leprechaun787-Nov-06 3:55

Leprechaun78

7-Nov-06 3:55

My terminology is probably incorrect, I don't have a lot of experience of programming in Windows (or anything else!), apologies for that. I thought a window was an instance of a class?

WindowDump uses GetClassName to extract the class name. This is an example of the output:

Class: List
Title:
ID: 0
hWnd: 0x00010d9a
Styles: WS_CHILD
Control Styles:
Dimension: (208,329) 95 x 125
State: Visible Enabled

If the class was a list box WindowDump would retrieve the contents using

SendMessage(hWnd, LB_GETTEXT, iPos, (LPARAM)szLine)

I'm wondering if there is a similar way to access the contents of a custom class?

Re: Extract information from a List class (Win32 API question)

David Crow7-Nov-06 4:03

Re: Extract information from a List class (Win32 API question)

7-Nov-06 4:03

Leprechaun78 wrote:
My terminology is probably incorrect...

It sounds as though you are confusing a Windows class (e.g., BUTTON, EDIT, LISTBOX, STATIC, COMBOBOX) with a C++ class.

Leprechaun78 wrote:
I'm wondering if there is a similar way to access the contents of a custom class?

Yes, but the target control would need to respond to the message for you to get anything from it.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Leprechaun788-Nov-06 2:16

Leprechaun78

8-Nov-06 2:16

Ok, I'll investigate ways of checking the properties of a C++ class. My thinking is that the application is passing the information to the operating system for it to display, so I want the operating system to output that information somewhere other than the screen (i.e. a text file). Do you think this is possible?

Re: Extract information from a List class (Win32 API question)

David Crow8-Nov-06 2:47

Re: Extract information from a List class (Win32 API question)

8-Nov-06 2:47

Leprechaun78 wrote:
Do you think this is possible?

Most things are, but that does not necessarily mean they are easy. While intercepting video output is likely doable, it would certainly not be trivial.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Leprechaun788-Nov-06 3:15

Leprechaun78

8-Nov-06 3:15

I'll keep investigating. Thanks for your thoughts Smile | :)

puzzled by the following calss defination

cy163@hotmail.com6-Nov-06 3:31

cy163@hotmail.com

6-Nov-06 3:31

I saw the puzzling class defination in the reference--
http://msdn2.microsoft.com/en-us/library/efk30beh(VS.80).aspx[^]

My question comes from the below line

***********************
CPrimeTest() : m_pCalcNext( new CEvent( FALSE, FALSE ) ) , m_pCalcFinished( new CEvent( FALSE, FALSE ) ) , m_pTerminateThread( new CEvent( FALSE, FALSE ) ) , m_iCurrentPrime( 0 ). If so, why not put them in the body of the class defination.
*******************************

-- How to explain it.

-- Can we treat 'm_pCalcNext', 'm_pCalcFinished' 'm_pTerminateThread' and 'm_iCurrentPrime' as four member variables of public type of the class

<br />
<br />
CPrimeTest { <br />
public: <br />
	<br />
	{ <br />
		// Create a thread that will calculate the prime numbers <br />
		CWinThread* pThread; <br />
		pThread = ::AfxBeginThread( PrimeCalcProc, this, 0, 0, CREATE_SUSPENDED, NULL); <br />
		pThread->m_bAutoDelete = FALSE; <br />
		pThread->ResumeThread(); <br />
		// Calcuate the first 10 prime numbers in the series on the thread <br />
		for( UINT i = 0; i < 10; i++ ) <br />
		{ <br />
			// Signal the thread to do the next work item <br />
			m_pCalcNext->SetEvent(); <br />
			// Wait for the thread to complete the current task <br />
			::WaitForSingleObject( m_pCalcFinished->m_hObject, INFINITE ); <br />
			// Print the result <br />
			TRACE( "The value of m_iCurrentPrime is: %d\n", m_iCurrentPrime ); <br />
		} <br />
		// Notify the worker thread to exit and wait for it to complete m_pTerminateThread->SetEvent(); <br />
		::WaitForSingleObject( pThread->m_hThread, INFINITE ); <br />
		delete pThread; } <br />
	<br />
	~CPrimeTest() <br />
	{ <br />
		delete m_pCalcNext; <br />
		delete m_pCalcFinished; <br />
		delete m_pTerminateThread; <br />
	} <br />
private: <br />
	// Determines whether the given number is a prime number static <br />
	BOOL IsPrime( INT ThisPrime ) <br />
	{ <br />
		if( ThisPrime < 2 ) return FALSE; <br />
		for( INT n = 2; n < ThisPrime; n++ ) <br />
		{ <br />
			if( ThisPrime % n == 0 ) <br />
				<br />
				return FALSE; <br />
		} <br />
		return TRUE; <br />
	} <br />
	// Calculates the next prime number in the series static <br />
	INT NextPrime( INT ThisPrime ) <br />
	{ while( TRUE ) <br />
	{ if( IsPrime( ++ThisPrime ) ) <br />
	{ return ThisPrime; } } } <br />
	// Worker thread responsible for calculating the next prime <br />
	// number in the series <br />
	static UINT __cdecl PrimeCalcProc( LPVOID lpParameter ) <br />
	{ CPrimeTest* pThis = static_cast<CPrimeTest*>( lpParameter ); <br />
	VERIFY( pThis != NULL ); VERIFY( pThis->m_pCalcNext != NULL ); <br />
	VERIFY( pThis->m_pCalcFinished != NULL ); <br />
	VERIFY( pThis->m_pTerminateThread != NULL ); <br />
	// Create a CMultiLock object to wait on the various events <br />
	// WAIT_OBJECT_0 refers to the first event in the array, WAIT_OBJECT_0+1 refers to the second <br />
	CSyncObject* pWaitObjects[] = { pThis->m_pCalcNext, pThis->m_pTerminateThread }; <br />
	CMultiLock MultiLock( pWaitObjects, 2L ); <br />
	while( MultiLock.Lock( INFINITE, FALSE ) == WAIT_OBJECT_0 ) <br />
	{ <br />
		// Calculate next prime <br />
		pThis->m_iCurrentPrime = NextPrime( pThis->m_iCurrentPrime ); <br />
		// Notify main thread calculation is complete <br />
		pThis->m_pCalcFinished->SetEvent(); <br />
	} <br />
	// Terminate the thread <br />
	::AfxEndThread( 0, FALSE ); <br />
	return 0L; <br />
	} CEvent* m_pCalcNext; <br />
	// notifies worker thread to calculate next prime <br />
	CEvent* m_pCalcFinished; <br />
	// notifies main thread current calculation is complete <br />
	CEvent* m_pTerminateThread; <br />
	// notifies worker thread to terminate INT m_iCurrentPrime; <br />
	// current calculated prime number <br />
};<br />
<br />
<br />
<br />
<br />

Cedric Moonen6-Nov-06 3:37

Cedric Moonen

6-Nov-06 3:37

cy163@hotmail.com wrote:
Can we treat 'm_pCalcNext', 'm_pCalcFinished' 'm_pTerminateThread' and 'm_iCurrentPrime' as four member variables of public type of the class

Why public ? They are private pointers which are instancied in the constructor (at the line you don't understand). Each of this pointers is a pointer to a CEvent class, and a CEvent class require two parameters for its constructor (I didn't look in detail, but it seems by seing the line you posted).

In fact this part of the line: m_pCalcNext( new CEvent( FALSE, FALSE ) ) is more or less equal to m_pCalcNext = new CEvent(FALSE,FALSE); in the body of the constructor.

So what do you don't understand exactly ?

Cédric Moonen
Software developer

Charting control [Updated - v1.1]

led mike6-Nov-06 4:24

led mike

6-Nov-06 4:24

Cedric Moonen wrote:
is more or less equal to

I'm not sure that I agree with your analysis.

m_pCalcNext( new CEvent(FALSE,FALSE))

is calling a constructor of whatever class m_pCalcNext is. The code posted is using the C++ Initialization List to call constructor of non-pointer member variables, and the same for the others.

led mike

Cedric Moonen6-Nov-06 4:38

Cedric Moonen

6-Nov-06 4:38

led mike wrote:
is calling a constructor of whatever class m_pCalcNext is

m_pCalcNext is a pointer to a CEvent object.

So this line: m_pCalcNext( new CEvent(FALSE,FALSE))creates a new instance of the CEvent class, the same way as m_pCalcNext = new CEvent(FALSE,FALSE);

The difference is that here it is in the initialization list and not in the constructor body (that's why I said more or less).

Cédric Moonen
Software developer

Charting control [Updated - v1.1]

led mike6-Nov-06 4:54

led mike

6-Nov-06 4:54

Cedric Moonen wrote:
m_pCalcNext is a pointer to a CEvent object.

Ahhh , didn't look at the link... my bad. Here is one for GWB.... "I was wrong" ... hear that GWB it's not that hard to do you [bleep][bleep][bleep][bleep].

led mike

Entrypoint problem in my project

toxcct6-Nov-06 5:03

toxcct

6-Nov-06 5:03

Use the <pre></pre> tag to format your code Suspicious | :suss:

You don't know where to start ? ask a good friend

[VisualCalc 3.0][Flags Beginner's Guide]

Raghavendra Pise6-Nov-06 3:12

Raghavendra Pise

6-Nov-06 3:12

Please anyone tell me which Entry point(Link->output->Entrypoint) should i use to create a _MBCS(Preproccessor defintion) Project?

Re: Entrypoint problem in my project

Mark Salsbery6-Nov-06 6:55

Mark Salsbery

6-Nov-06 6:55

WinMain() ?

SetDiBitsToDevice()

Waldermort6-Nov-06 3:06

Waldermort

6-Nov-06 3:06

I making a call to SetDIBitsToDevice() specifying a smaller width and height than the actual DIB section. The trouble is the image is always drawn bottom up. ie the bottom edge of the image is locked to the bottom of the specified rectangle. Could somebody please tell me how to draw the image correctly from the top down?

Re: SetDiBitsToDevice()

C^hris L^osinger6-Nov-06 3:19

C^hris L^osinger

6-Nov-06 3:19

with most DIB funcitons, you can just give a negative value for DIB height, to flip the output.

it's worth a try..

image processing | blogging

Re: SetDiBitsToDevice()

Waldermort6-Nov-06 3:35

Waldermort

6-Nov-06 3:35

I tried, without success Frown | :(

, I also tried modifying the other params and creating the DIB with a negative height, but so far nothing has worked.

Here is the function call.

SIZE size = { _x2 - _x1, _y2 - _y1 };
//  SIZE size = GetSize();
    POINT SrcOrigin = {0,0};
    ::SetDIBitsToDevice(
        hdc, 
        _x1, _y1, 
        size.cx, size.cy,
        SrcOrigin.x, SrcOrigin.y,
        SrcOrigin.y, size.cy - SrcOrigin.y, 
        m_ppvBits, m_DIBinfo, 
        m_iColorDataType );

If I swap the commented line, it works fine, but it draws the full sized bitmap which is not what I want.

Re: SetDiBitsToDevice()

Waldermort6-Nov-06 4:11

Waldermort

6-Nov-06 4:11

No matter, I managed to get it working correctly.

SIZE size = GetSize();
POINT SrcOrigin = {0,size.cy - (_y2-_y1) };
::SetDIBitsToDevice(
    hdc, 
    _x1, _y1, 
    _x2-_x1, _y2-_y1,
    SrcOrigin.x, SrcOrigin.y,
    0, size.cy, 
    m_ppvBits, m_DIBinfo, 
    m_iColorDataType );

seems I had some of the paramaters a little messed up.

how to call a function a scheduled time?

Banks K6-Nov-06 3:03

Banks K

6-Nov-06 3:03

now i am able to execute a exe at scheduled time.

but i have to call a function at scheduled time.

suppose a service starts and at scheduled time, can i call a function of that service which is allready running by using task scheduler.

if any have idea please share with me.

thanks & regards
bankey

benjymous6-Nov-06 3:24

benjymous

6-Nov-06 3:24

It sounds like you want two exes

A) Your service
B) A helper app that sends a message to (A) and tells it to perform its function

The two can talk using inter process communication[^]

--
Help me! I'm turning into a grapefruit!
Buzzwords!

David Crow6-Nov-06 3:59

6-Nov-06 3:59

Banks K wrote:
but i have to call a function at scheduled time.

Set up a timer via SetTimer(). As each WM_TIMER message is received, check the current time with the scheduled time. If they match, call the function.

Banks K wrote:
...can i call a function of that service which is allready running by using task scheduler.

No.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

led mike6-Nov-06 4:27

led mike

6-Nov-06 4:27

Banks K wrote:
at scheduled time, can i call a function of that service which is allready running by using task scheduler.

I don't understand. A "service which is allready running" would be a process. One process cannot "call functions" in another process. Please be specific when asking questions so we have any clue how to answer.

led mike

prasad_som6-Nov-06 19:05

prasad_som

6-Nov-06 19:05

Banks K wrote:
suppose a service starts and at scheduled time, can i call a function of that service which is allready running

For this you need to have interfaces exposed on that service.

Banks K wrote:
by using task scheduler.

AFIK, taskscheduled runs only executables at scheduled time. You can access interfaces exposed by service in an executables, call required functions and schedule that exe using task schedular.

Prasad
Notifier using ATL | Operator new[],delete[][^]