Re: Memory Device context+Createcompatible Bitmap related query - C / C++ / MFC Discussion Boards

Re: Which message window receives after all when it open?

gUrM33T1-Apr-04 16:44

gUrM33T

1-Apr-04 16:44

i guess PeekMessage can be used for this purpose.

Gurmeet S. Kochar

If you believe in God, it's because of the Devil

Databases and threads

islheg1-Apr-04 3:09

islheg

1-Apr-04 3:09

I developed an database application using VC++ and Micorsoft Access driver as the ODBC source. There are 2 threads in the application both accessing the same table. The first thread writes data in the table and the second thread reads and deletes data from the table. Here is a snapshot of the code of the second thread:

while (!attackRecSet->IsEOF())
{
.
.
.
.
.
.
try
{
attackRecSet->Delete();
attackRecSet->MoveNext();
} //try
catch(CDBException *e)
{
MessageBox(NULL, e->m_strError, "Error", MB_OK);
e->Delete();
} //catch
} //while

An error message occurs because of the delete function and the thread stops working. the error message is:

" Could not update; currently locked by user 'admin' on machine ISLAM_COMPUTER'. "

and when I press OK the following message occurs for ever (it reoccurs if I press the OK button):

" Invalid cursor position; no keyset defined. "

If I commented the delete function the thread will work perfectly. I searched the MSDN for an explanation but with no use. Could anyone tell where could I find an explanation for this error.

Islam Hegazy

islam

Re: Databases and threads

Prakash Nadar1-Apr-04 4:45

Prakash Nadar

1-Apr-04 4:45

You need to use syncronization objects like Mutex or CriticalSection to ensure that only one thread works with the database system.

MSN Messenger.
prakashnadar@msn.com

"If history isn't good, just burn it." - Sidhuism.

Entering new lines in edit box

satcat1-Apr-04 3:02

satcat

1-Apr-04 3:02

Hi all!

In my aplication I have an edit box (1) where the user can add text that will appear in other edit box (2). In (2) each text is concatenated with prior one, but when I try to concatenate "\n" so the next text appear in a new line, I get a strange character between two texts instead of a new line. The edit box (2) is a read-only one and Want_Return mode is selected. How could I concatenate the texts so each one appears in new lines?

Thank you in advance.

Re: Entering new lines in edit box

David Crow1-Apr-04 3:24

David Crow

1-Apr-04 3:24

satcat wrote:
...I get a strange character between two texts instead of a new line.

Are you using the ES_MULTILINE style?

satcat wrote:
How could I concatenate the texts so each one appears in new lines?

Use \r\n instead.

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

Re: Entering new lines in edit box

basementman1-Apr-04 5:02

basementman

1-Apr-04 5:02

You need to use ES_MULTILINE style and should append "\r\n", rather than just the line feed.

onwards and upwards...

Memory Device context+Createcompatible Bitmap related query

JHAKAS1-Apr-04 1:59

JHAKAS

1-Apr-04 1:59

In a function i am doing following things

Function starts

	<br />
	// m_Analyser is object of class CAnalyser and having a member <br />
        // CBitmap i.e. CBitmap  m_WFRBitmap;<br />
	// GetWFRBitmap() returns that Bitmap i.e.<br />
        // CBitmap *GetWFRBitmap() { return &m_WFRBitmap; }<br />
	CBitmap *pWFRBitmap = pDoc->m_Analyzer.GetWFRBitmap();<br />
	pWFRBitmap->CreateCompatibleBitmap(&ClientDC, 860, 1100);<br />
	ClientDC.SetMapMode(MM_LOENGLISH);<br />
<br />
	CDC MemDC;<br />
	MemDC.CreateCompatibleDC(&ClientDC);<br />
	MemDC.SelectObject(pWFRBitmap);<br />
	MemDC.SetMapMode(MM_TEXT);<br />
	//**********<br />
	//	Draw to the Memory device context<br />
	//*************<br />
	MemDC.SetMapMode(MM_LOENGLISH);<br />

Function ENds

1.0 What exactly will happen. To the bitmap in CAnalyser and MemDC. Will the content of MemDC will be written to CBitmap which is attached to MemDC.

2.0 What will happen if every thing remains same and i make CDC MemDC global?

3.0 I want to make another function in CAnalyser like SetBitmap and want to assign the content of the CDC MemDC (global) to assigned to that CBitmap member of CAnalyser m_WFRBitmap so that i can draw the bitmap again whenever my screen get redrawn instead of carrying out complete drawing process again and again.
How to do this?

Rose | [Rose]

Leave your mark wherever you go

Re: Memory Device context+Createcompatible Bitmap related query

John R. Shaw1-Apr-04 9:36

John R. Shaw

1-Apr-04 9:36

1.0 Yes! Because MemDC contains your bitmap and therefore is draw on your bitmap. Before calling CreateCompatibleBitmap() make sure that the bitmap does not already exist or you will have problems. DO NOT for get to restore the origanal bitmap to the MemDC after drawing to it.

2.0 & 3.0 The only reason for making MemDC global is so you will not have to call CreateCompatibleDC() more than once. You will still need to clean it up after evey usage though. That is call SelectObject(pOldBitmap) after drawing to bitmap or using MemDC to blit the image to the client area.

Lookup CDC::CreateCompatibleDC() in the MSDN library (there is sample code there)

INTP

How to detect that background under child window is changed?

vgrigor1-Apr-04 0:48

vgrigor

1-Apr-04 0:48

How to detect that background under child window is changed?

Problem is following:

I use owner-drown CStatic ( rectanule) as
surround rectangle, but fill the background under it.
In CDialog:: OnEraseBackground,
I call that CStatic::OnEraseBackground.

At first time all controls appears,
but next, if I move some window around that CStatic:

controls are under backgrounf - do not know that background is filled and
not redraw self - so thay are hide under filling.

How for child windows to know that background is changed ?

I use a collection of controls that placed within filled CStatic rectangle,
so I can command
Invalidate(0);
UpdateWindow(); for each.

But this is not helps.

How to renew controls when background owner-drawn change
(in CStatic::OnEraseBackground ) ?

Helps if I command to renew full CDialog, but it happens at too much cost of renewing all controls , not within desired rectangle,
but result need as in that case.

How to achieve it ?

thanks you.

How to obtain interface ip from destination ip ?

VF1-Apr-04 0:04

1-Apr-04 0:04

I have server with several network card. I need to route messages (in my server software) from one of them to another. And I need to include my server machine ip in the messages. How to obtain interface ip from destination ip ?
Thank you in advance.

Re: How to obtain interface ip from destination ip ?

Antony M Kancidrowski1-Apr-04 1:17

Antony M Kancidrowski

1-Apr-04 1:17

If you use winsock and ping (echo request) the destination the echo reply will have the IP of your i/f in its destination address of the tcp packet. Smile | :)

Ant.

Re: How to obtain interface ip from destination ip ?

Mike Dimmick1-Apr-04 1:49

Mike Dimmick

1-Apr-04 1:49

I think you want GetBestInterface, from the IP Helper API. You can then use GetIpAddrTable to determine the set of IP addresses for that interface.

If you're designing this protocol, though, I recommend that you don't include the IP address in the message. Your protocol won't work across Network Address Translation (for example, from a private to a public network), and it won't work on IPv6 networks. The client should already know which server it's connecting to.

If the server needs to know the IP address of the client, you should pass a sockaddr_in structure to accept (for TCP connections), or use recvfrom for UDP-based protocols. Use sockaddr_in6 for an IPv6 socket.

Stability. What an interesting concept. -- Chris Maunder

set cursor of SDI

MeWithNoName1-Apr-04 0:04

MeWithNoName

1-Apr-04 0:04

Hi all,

I just want to change the mouse cursor of the entire SDI to special (custom) cursor.
I tried a lot of thing, but it doesnt work. Any ideas?

Thanks,

Paul

Re: set cursor of SDI

Milton Karimbekallil1-Apr-04 0:39

Milton Karimbekallil

1-Apr-04 0:39

Hi
1)Override OnSetCursor of CView
2)Add ::SetCursor(AfxGetApp()->LoadStandardCursor(IDC_WAIT));
3)Remove the base class call CView::OnSetCursor
4)Add return TRUE;

rgds ...mil10

vector math on different pc processors (amd, intel)

Mediate31-Mar-04 23:33

Mediate

31-Mar-04 23:33

Hi,

I'm interested in porting some mac c++ code to PC. I use al lot of heavy vector math. There are, probably, libraries for this. But how do you use them all, so you don't have to create new applications or new code for every processor? (p3, p4, athlon, athlon xp, etc.)

Does anyone know if there are templates, macros or something for this?
I just looked at OptiVec (http://www.optivec.com/), does anyone have some experience with this?

Great to hear something, some pointers/url/etc,

Best Regards,

Aram

Re: vector math on different pc processors (amd, intel)

Antony M Kancidrowski1-Apr-04 1:31

Antony M Kancidrowski

1-Apr-04 1:31

I can't understand how C++ vector math can be different under different processors.

Ant.

Re: vector math on different pc processors (amd, intel)

Alexander ^M.,1-Apr-04 3:37

Alexander ^M.,

1-Apr-04 3:37

The only difference could be when you use SIMD instructions.

Don't try it, just do it! Wink | ;-)

Re: vector math on different pc processors (amd, intel)

Mediate1-Apr-04 23:18

Mediate

1-Apr-04 23:18

OK, I'll put it like this.

I'm using SIMD instructions, are there some libaries which will convert my high-level code to the proper (processor dependent) low-level machine code, in order to get the fastest vector math possible on every PC processor?

Or do I need to build this in my self, checking which processor and then applying the right optimized vector code for that one?

what about www.optivec.com, could this be where I am looking for?

thanks!

subst programatically

bruno leclerc31-Mar-04 22:30

bruno leclerc

31-Mar-04 22:30

Hi,
Does someone knows how to make a subst programmaticaly in c++ under WNT4 ?
Thanks

Re: subst programatically

David Crow1-Apr-04 3:27

David Crow

1-Apr-04 3:27