Re: STACKS AND QUES - C / C++ / MFC Discussion Boards

abc87615-Apr-04 9:52

15-Apr-04 9:52

I am connecting to a remote SQL Server in my software. Its all working fine.. but on some PCs it gives exception and connection is not made. What are strict requirements for connecting to a remote SQL Server. My SQL Server uses SQL Server based authentication.. I heard that Win XP machine cant conenct to SQL Server if there is no password of Win XP machine.. plz tell me strict requiremnts

Thanks

Muhammad Shoaib Khan
http://geocities.com/lansolution

VB client for a C++ api

Jim Crafton15-Apr-04 9:48

Jim Crafton

15-Apr-04 9:48

I have been given a rather unfortunate assignment at work:

I have to look into what it would take to put a COM wrapper around a small multi-threaded C++ API that I wrote. It seems a client is interested in the API if it can support VB. I have the option of telling my boss it's impossible and that he should tell them to toss off. My assumptions are that they are using VB6.

I've done ATL before but never in wrapping a multithreaded API that had to work in VB. Any suggestions? Besides the obvious that all the com objects need to be dual interface (IDispatch), is there any thing funky I need to do to handle the fact that the lib uses multiple threads internally?

Basically the VB client would do nothing more than

- create the app instance (the app would house my library)
- init the app (App.Init or something like that)
- run it (App.Run)
- respond to events

The VB client has no need to work in multiple threads, or be aware of their presence.

Any suggestions would be *most* appreciated!

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Re: VB client for a C++ api

Gary R. Wheeler15-Apr-04 11:58

Gary R. Wheeler

15-Apr-04 11:58

Jim Crafton wrote:
The VB client has no need to work in multiple threads, or be aware of their presence.

You will need to be careful how your events are passed to the VB client. It may expect or require that callbacks to it are on the GUI thread.

It's probably not the right way to do it when using COM (all that apartment stuff comes to mind), but I've used the 'hidden window and user-defined messages' trick to handle this. In the GUI thread, create a hidden window. Your event handler, which is called on an unknown thread, uses ::PostMessage and the window's handle to drop a message into the hidden window. The hidden window, running on the GUI thread, processes the user-defined message and handles the event. If the event has information, you can use the WPARAM and LPARAM arguments for small things, or pass pointers to objects allocated from the heap. If you do the latter, you need to ensure that the hidden window has a WM_DESTROY handler that will run the message pump dry via PeekMessage and delete the arguments.

The event handler and the GUI thread are decoupled in this case, which can be useful. The event handler doesn't block (except briefly during the PostMessage call). Events are maintained in order by the hidden window message queue.

Software Zen: delete this;

WinApp::OnIdle

_-:: PhOeNiX ::-_15-Apr-04 9:44

_-:: PhOeNiX ::-_

15-Apr-04 9:44

I've tried to make an Idle time processing in an MDI project, but even if there are no messeges for the window the lCount doesn't go higher then 1... => I've tried to see what's going on in the thCore, but I couldn't figure'it out.

Any tip would be appreciated.
10x

..:: a l i e n ::..

Re: WinApp::OnIdle

PJ Arends15-Apr-04 11:53

PJ Arends

15-Apr-04 11:53

CWinApp::OnIdle will return FALSE when it is done. If you want to insert idle processing after that, you have to get your override to return TRUE. If it returns TRUE, OnIdle() will be called with an increased lCount.

Sonork 100.11743 Chicken Little

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STACKS AND QUES

PDALE15-Apr-04 8:04

PDALE

15-Apr-04 8:04

Can anyone assist with a template or code for stacks and ques?? I have been thrown into a class with little foundation, so any help is appreciated. OMG | :OMG:

Hi_Pdale Here

Re: STACKS AND QUES

toxcct15-Apr-04 8:16

toxcct

15-Apr-04 8:16

these are the standard C++ container :

#include <list>
#include <vector>
#include <queue>

all these are from the std:: namespace.

you can also read The C++ language from Bjarne Stroustrup for more infos.

TOXCCT >>> GEII power

Re: STACKS AND QUES

Jim Crafton15-Apr-04 10:15

Jim Crafton

15-Apr-04 10:15

If you just want a way to store a collection an easy place to get started is indeed std::vector or std::list. If you *specifically* are looking for a stack/queue behaviour, then take a look at std::deque

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Re: STACKS AND QUES

Jim Crafton15-Apr-04 10:17

Jim Crafton

15-Apr-04 10:17

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclang98/html/DEQUE_DEQUE.asp[^]

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Maskededit control

C++NewBe15-Apr-04 7:49

C++NewBe

15-Apr-04 7:49

I am having a tough time getting maskededit control to display any Alphanumeric text in C++. I have used maskededit control in VB with no problem. I need some help.....

Re: Maskededit control

David Crow15-Apr-04 10:14

David Crow

15-Apr-04 10:14

C++NewBe wrote:
I am having a tough time getting maskededit control...

Which one? VC++ does not have a built-in one (i.e., comctl32.dll).

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Maskededit control

C++NewBe15-Apr-04 10:19

C++NewBe

15-Apr-04 10:19

Yes it does not but you can insert it in the project using "Insert ActiveX Control" and select "Microsoft Masked Edit Control, version 6.0".

Re: Maskededit control

David Crow15-Apr-04 10:33

David Crow

15-Apr-04 10:33

Of course. It's not quite built-in as it is an external ActiveX control, but a masked edit control nonetheless. What specific problem are you having with it? You indicated that alphanumeric text was troubling you. Does that imply that alpha-only and numeric-only are working fine? I'm just trying to narrow down if it's a specific usage of the control that's the problem, or the control as a whole. What mask/format are you trying to use?

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Maskededit control

C++NewBe15-Apr-04 10:42

C++NewBe

15-Apr-04 10:42

Whether I use a mask for numeric or no mask for just plain string, I am not able to display anything at all in the control.

I created a simple project with just the dialog and the control and I am still unable to display any string.

Serialize

Demian Panello15-Apr-04 5:48

Demian Panello

15-Apr-04 5:48

I'm having troubles to serialize my object.
I have a class called: CDecDatabase that have a member of type CObArray of CSistema object, (an array of CSistema objects).
CSistema object have 3 arrays CObArray, (arrays of objects CP1, CP2 y CP3).
All the object have a Serialize function.

First I invoke CDecDatabase::Serialize(), then, this function call Serialize() of the array of CSistema and this function call the methods Serialize() for the other arrays of CP1 CP2 and CP3 objects.

Something I have saved but this is not all the data.
I don't know if I'm serialize the objects in the right order.

Thank you.

Demian.

Multi threading

dreamerzz15-Apr-04 5:13

dreamerzz

15-Apr-04 5:13

Hi,

Currently i am working on single document interface MFC to create a small update program to the database to change the values store in the fields.

However, in order to let the program run "automatically", i have to used thread. But I know nuts about threading.

I have attached the main part of the updating of the program below. pls kindly help..I have read up on books about C++ on the thread function. the book says, to create and start, i have to use AfxBeginThread and have some arguements inside. and a function UINT MyThreadFunction(LPVOID pParam).

Really need help on this as its very urgent to me... Thanks a million.

<br />
void CUpdateView::OnUpdatedb() <br />
{<br />
	// TODO: Add your control notification handler code here<br />
<br />
	double propa_update = 0.814;<br />
	double resp_update = 0.205;<br />
	double link_update = 1.19;<br />
<br />
	//get a pointer to the recordset<br />
	CUpdateDoc* pDoc = GetDocument();<br />
	UseRecordset* pUseRecordset	= &pDoc->m_UseRecordset;<br />
<br />
	do<br />
	{<br />
		//Allows the current record to be edited<br />
		pUseRecordset->Edit();<br />
			<br />
		//increment in the values from the database<br />
		pUseRecordset->m_propatime = pUseRecordset->m_propatime*propa_update;<br />
		pUseRecordset->m_respondtime = pUseRecordset->m_respondtime*resp_update;<br />
		pUseRecordset->m_link = pUseRecordset->m_link*link_update;<br />
		<br />
		//Saves the current changes to the database<br />
		pUseRecordset->Update();<br />
<br />
		//Reruns the current SQL query to refresh the recordset<br />
		pUseRecordset->Requery();<br />
<br />
		//Update the form<br />
		UpdateData(true);<br />
	}while(check_exit!=0);<br />
}<br />
<br />
void CUpdateView::OnExit() <br />
{<br />
	check_exit=0;<br />
	OnExit();<br />
}

Re: Multi threading

David Crow15-Apr-04 7:16

David Crow

15-Apr-04 7:16

Sounds like you need a worker thread (i.e., a thread with no message pump). If so, read this article. When it comes time to update the database, create the thread and put your update code in this thread. You might want to periodically post a message back to the main thread indicating progress.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Multi threading

dreamerzz15-Apr-04 20:38

dreamerzz

15-Apr-04 20:38

Hi,

I have read the article that you gave me and have tried implementing the methods into my program.. however, that are still one error which i hope u could help me..

<br />
void CUpdateView::OnUpdatedb() <br />
{<br />
        // TODO: Add your control notification handler code here<br />
        running = true;<br />
        AfxBeginThread(run, this);<br />
<br />
}<br />
<br />
UINT CUpdateView::run(LPVOID p)<br />
{<br />
	CUpdateView* pView = (CUpdateView*)p;<br />
	pView->run();<br />
<br />
	double propa_update = 0.814;<br />
	double resp_update = 0.205;<br />
	double link_update = 1.19;<br />
<br />
	do<br />
	{<br />
		//get a pointer to the recordset<br />
		CUpdateDoc* pDoc = GetDocument();		UseRecordset* pUseRecordset	= &pDoc->m_UseRecordset;<br />
<br />
		//Allows the current record to be edited<br />
		pUseRecordset->Edit();<br />
			<br />
		//increment in the values from the database<br />
		pUseRecordset->m_propatime = pUseRecordset->m_propatime*propa_update;<br />
		pUseRecordset->m_respondtime = pUseRecordset->m_respondtime*resp_update;<br />
		pUseRecordset->m_link = pUseRecordset->m_link*link_update;<br />
		<br />
		//Saves the current changes to the database<br />
		pUseRecordset->Update();<br />
<br />
		//Reruns the current SQL query to refresh the recordset<br />
		pUseRecordset->Requery();<br />
	}while(check_exit!=0);<br />
<br />
	return 0;<br />
}<br />
<br />
void CUpdateView::OnExit() <br />
{<br />
	running = false;<br />
}

The part that i have it bold is giving mi the error..

the error message is :

'CUpdateView::GetDocument' : illegal call of non-static member function
This problem is it because i have the UINT CUpdateView::run(LPVOID p) declare as static?

see declaration of 'GetDocument'
My declaration is CUpdateDoc* GetDocument(); in CUpdateView Class

Re: Multi threading

David Crow19-Apr-04 2:28

David Crow

19-Apr-04 2:28

See if this helps:

//get a pointer to the recordset
CUpdateDoc* pDoc = pView->GetDocument();

Keep in mind that what you have will not work if the primary thread is also accessing the document or the recordset.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Multi threading

dreamerzz20-Apr-04 2:14

dreamerzz

20-Apr-04 2:14

Hi,

Thanks for ur help.

dReaMerzZ

Visual Basic-like editor for VC++ 6.0?

AAntix15-Apr-04 4:55

AAntix

15-Apr-04 4:55

I can remember a tool a couple years back that provided a dialog editor similar to VB, where control colors, etc could be easily changed, but it was for VC++. Does anyone remember the exact product?

Jim
QTExtender - The OFFICIAL addon for QuoteTracker.

Re: Visual Basic-like editor for VC++ 6.0?

toxcct15-Apr-04 6:54

toxcct

15-Apr-04 6:54

wasn't it the "Borland C++" one ?

TOXCCT >>> GEII power

Re: Visual Basic-like editor for VC++ 6.0?

David Crow15-Apr-04 7:13

David Crow

15-Apr-04 7:13

Yes, Borland had a very nice one called Resource Editor. Whether it's the one in question remains to be seen.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Visual Basic-like editor for VC++ 6.0?

AAntix15-Apr-04 7:21

AAntix

15-Apr-04 7:21

No, I don't believe it was Borland.

The interface was identical to VB's, with the obvious exception it generated the appropriate gui code on the backend.

Jim
QTExtender - The OFFICIAL addon for QuoteTracker.

Re: Visual Basic-like editor for VC++ 6.0?

Prakash Nadar15-Apr-04 17:55

Prakash Nadar

15-Apr-04 17:55

I think VS.NET has that feature.

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