C / C++ / MFC

FirstPrevNext

Message Pump Mechanism 10-Mar-01 4:48 10-Mar-01 4:48  QUESTION on message pumping: I have posted this a while back. But I hope to confirm my understanding is correct: QUESTION 1: What generates the BN_CLICKED message when a user click a mouse button over a button? Is the following description correct? 1. The user clicks a mouse button. 2. The mouse driver puts an item into the system input queue. 3. A system thread, which handles user input, retrieves this item and, using coordinates recorded by the driver, determines to which window this message should be posted. Mouse messages are always sent to the window under the cursor (unless another window has captured mouse input). Given the window handle the system detemines the thread to which this window belongs and posts WM_LBUTTONDOWN and WM_LBUTTONUP messages to the message queue of this thread. Note, the message is posted to only one message queue since the system knowns to which thread the window belongs. 4. The application object, derived from CWinApp, will pickup the message from its thread message queue. Then route this message to the appropriate controls/windows. 5. Button window procedure receives WM_LBUTTONUP message and do the following: (i) update the display of the button (depressed state and then the release state.) //QUESTION: SendMessage( ) OR PostMessage( )?? (ii) sends WM_COMMAND/BN_CLICKED notification to "the parent window" or a "particular" control. (iii) posts WM_COMMAND/BN_CLICKED notification to the application/thread message queue 6. Message map can be "expanded" to a subroutine that searches the message map upon reciept of a message/notification, then route the message to "appropriate" message handler in response a mapped message. (This brings up the issue of message routing. ie. Things like searching the view class maps, then the document class, then the frame windows, then the app...) QUESTION 2: Quote from MSDN: [OPEN QUOTE] "This message is sent when the user selects a command item from a menu, when a control sends a notification message to its parent window, or when an accelerator keystroke is translated. WM_COMMAND wNotifyCode = HIWORD(wParam); (EXAMPLE: BN_CLICKED??) wID = LOWORD(wParam); hwndCtl = (HWND) lParam; (WHY DO U NEED HANDLE WHEN CONTROL IDENTIFIER IS PROVIDED - wID ??) " [CLOSE QUOTE] (1) When a button is clicked, is a WM_MESSAGE sent (or posts) to its parent window? or to its parent window's message queue? or to its parent's window procedure? (2) Which parent? Immediate or top level in the hierachy? (3) When a button is clicked, is a WM_MESSAGE (with BN_CLICKED as wParam) sent or is a BN_CLICKED messages sent? (4) Does "notification" messages and "messages" refer to the same thing? Thanks. Re: Message Pump Mechanism Tim Deveaux10-Mar-01 6:33 Tim Deveaux 10-Mar-01 6:33  I guess the reason your message has gone unanswered is that its tough to answer - here's just a couple of thoughts... First, there's a mix of win32 messaging architecture and MFC here - MFC has a way cool way of allowing you to map command messages to classes that you wouldn't ordiarily expect to get them (i.e. have no hwnd), and this mech is the stuff of DiLascia-like articles in itself, but I would think we should get the win32 stuff nailed down first. Second, a recommendation - I've been struggling lately with a messaging problem that has me baffled - I picked up Jeffrey Richters book 'Advanced Windows' to check out his chapter on Windows Messaging and Asychronous Input - I think now I better read the whole book! You might want to check it out. There's so much to look at here - just hard to do all at once. HTH Check sign ... Hadi Rezaee10-Mar-01 0:56 Hadi Rezaee 10-Mar-01 0:56  <<< In the name of GOD >>> Hi all. I want to set Check Sign inside text in menu. My program is in dialog based mode. void CTestglobalDlg::OnUpdateKhar(CCmdUI* pCmdUI) { pCmdUI->SetCheck(TRUE); } So, please say to me, how can i set dynamicaly check sign ... Hadi Rezaie Re: Check sign ... Christian Graus10-Mar-01 1:57 Christian Graus 10-Mar-01 1:57  <<< In the name of GOD >>> There is an article on Codeproject on doing this in a dialog app, I remember seeing it. Christian The content of this post is not necessarily the opinion of my yadda yadda yadda. To understand recursion, we must first understand recursion. Check sign ... Hadi Rezaee10-Mar-01 0:53 Hadi Rezaee 10-Mar-01 0:53  <<< In the name of GOD >>> Hi all. I want to set Check Sign inside text in menu. My program is in dialog based mode. void CTestglobalDlg::OnUpdateKhar(CCmdUI* pCmdUI) { pCmdUI->SetCheck(TRUE); } So, please say to me, how can i set dynamicaly check sign ... Hadi Rezaie Check sign ... Hadi Rezaee10-Mar-01 0:51 Hadi Rezaee 10-Mar-01 0:51  <<< In the name of GOD >>> Hi all. I want to set Check Sign inside text in menu. My program is in dialog based mode. void CTestglobalDlg::OnUpdateKhar(CCmdUI* pCmdUI) { pCmdUI->SetCheck(TRUE); } So, please say to me, how can i set dynamicaly check sign ... Hadi Rezaie audio problems Ruth Farmery9-Mar-01 20:55 Ruth Farmery 9-Mar-01 20:55  i am writing an audio codec as part of a larger project. it involves playing etc of wave and mp3 files. i am using a class that simplifies the use of idirectsound for wave and xaudio.lib for the mp3s. in the test file (dialog based) i have written my class works fine but when added to a console application it won't play anything or it is not outputting sound can anyone shed any light on this matter? can dsound.lib be used in a console based app or only dialog based? thanks ruth Linking resource problem 9-Mar-01 20:49 9-Mar-01 20:49  Hi, I am trying to compile and link a workspace for a dll which has only resource files. Before it used to complie and link.. I changed a a bitmap file by just replaing it with a new one with the same name.. After that whenever i try to build, i get the following errors: "CVTRES : fatal error CVT1106: cannot write to file" "res32.res : fatal error LNK1123: failure during conversion to COFF: file invalid or corrupt" I cleaned and tried to rebuild all, also tried restarting the machine. Still the same error is being displayed.. can anybody suggest me to avoid this error? The recent bitmap opens perfectly in mapaint or vc editor.. Regards, Nayan Re: Linking resource problem l a u r e n10-Mar-01 1:00 l a u r e n 10-Mar-01 1:00  have you tried deleting the output directory completely (ie, debug or release) ? --- "every year we invent better idiot proof systems and every year they invent better idiots" Re: Linking resource problem Tim Deveaux10-Mar-01 13:26 Tim Deveaux 10-Mar-01 13:26  The linker seems to be invoking the coversion utility to convert an OMF object file to COFF format. This is default behavior. I found this note in the MSDN regarding ".Lib Files as Linker Input": "LINK cannot link a library of 32-bit OMF objects created by the 16-bit version of LIB. To use an OMF library, you must first use the 16-bit LIB (not provided in Visual C++ for Windows NT) to extract the objects. You can then either link the OMF objects or use the 32-bit LIB to convert them to COFF and put them into a library. You can also use the EDITBIN.EXE tool to convert an OMF object to COFF. " Not sure if this is the prob, but worth a look. URGENTLY Need Help #realJSOP9-Mar-01 3:53 #realJSOP 9-Mar-01 3:53  1) VC6 (no service packs applied I don't think - installed from MSDN January 2001 Enterpise CD's) 2) Windows 2000/SP1 3) Our app is an MFC MDI app with MFC is staticaly linked. I'm trying to embed a CPropertySheetEx in a dialog box. In Debug mode, it works fine, but in release it doesn't. 4) This code works on Windows 98 AND Windows NT 4 (SP5-6a) in both release and Debug modes. 5) It fails when I call the Create function in CPropertySheetEx, but since I'm in release mode, I can't trace into the code. 6) Do I have to install a VC6 service pack to fix this? If anyone can provide any hints, tips, experiences or other helpful tidbits, I'd love to hear about it. Send mail here: john.simmons@brooks.af.mil Many thanks in advance. Re: URGENTLY Need Help l a u r e n9-Mar-01 20:42 l a u r e n 9-Mar-01 20:42  hey john i would strongly recommend applying service pack 4 at least (prolly 5 if you can get it) ... if the problem still persists it might be something more fundamental --- "every year we invent better idiot proof systems and every year they invent better idiots" Re: URGENTLY Need Help #realJSOP12-Mar-01 2:34 #realJSOP 12-Mar-01 2:34  Applied service pack 4 after leaving the original message. No change. We had to deliver a laptop (wint Win2K installed) with the application on it and were running through all the dialogs. This dialog crashed the app. Since we had to deliver the machine on Friday, and in anticipation of not getting an answer in team through this forum, we re-wrote the dialog to not use tabs (took about an hour). I am still curious as to why this wouldn't work on Win2k, but works everywhere else. Since there's a moderate amount of source code involved, maybe I could post this as an article and let everybody else have a stab at it too. Re: URGENTLY Need Help Tim Deveaux10-Mar-01 12:54 Tim Deveaux 10-Mar-01 12:54  > but since I'm in release mode, I can't trace into the code. Go to the project settings for the Release build. In the C++ (General Category) select Program Database for Debug Info. Next, in the Link tab (also General) check the Generate Debug Info box. You may not be able to see things as well in the watch window, but at least you'll be able to see code and call stack. This is a great help for dealing with the effects of optimizations, uninitialized vars etc. Re: URGENTLY Need Help #realJSOP12-Mar-01 2:37 #realJSOP 12-Mar-01 2:37  Thanks - I'll try that. Re: URGENTLY Need Help #realJSOP12-Mar-01 9:56 #realJSOP 12-Mar-01 9:56  Well, I wrote a little test app that includes only the code necessary to build a dialog box with an embedded property sheet, and ran it on three windows 2000 systems. It worked on every one of them. This leads me to the conclusion that it's something else in the app that's crashing when the dialog box in question is being initialized. "Good thing" - It wasn't my dialog box code that was causing the problem "Bad thing" - I still don't know what the problem actually is yet. Grrrr... Difference between ADO and ADODB 8-Mar-01 22:11 8-Mar-01 22:11  What is the difference between ADO and ADODB? Thanks. Difference between ADO and ADODB 8-Mar-01 22:11 8-Mar-01 22:11  What is the difference between ADO and ADODB? Thanks. Difference between ADO and ADODB 8-Mar-01 22:11 8-Mar-01 22:11  What is the difference between ADO and ADODB? Thanks. Difference between ADO and ADODB 8-Mar-01 22:10 8-Mar-01 22:10  What is the difference between ADO and ADODB? Thanks. Process Infomation 8-Mar-01 20:13 8-Mar-01 20:13  Hi,guys There's a question troubled me for a long while,that is How can I know a process is RUNNING or NOT RESPONDING in my program,using Visual c++? anyone can supply useful info is appriciate Re: Process Infomation l a u r e n8-Mar-01 21:06 l a u r e n 8-Mar-01 21:06  thought i posted an answer to this when you originally posted the question --- "every year we invent better idiot proof systems and every year they invent better idiots" Re: Process Infomation Tim Deveaux10-Mar-01 13:07 Tim Deveaux 10-Mar-01 13:07  You might check out the docs for SendMessageTimeout. Looks to me like this might be the method Task Manager uses to send an initial WM_CLOSE to a process' main window. All you're really checking for here is if the message pump is pumping - if the app is just dutifully computing the first 23 gazillion digits of e, it will appear hung. Button Coordinates in ClientRect 8-Mar-01 17:46 8-Mar-01 17:46  This is probably really easy .. but here goes I have a CButton object in my dialog application and I have the x,y,x2,y2 coordinates of the actual dialog application but need to find out what the x,y coordinates of the top/left of the button object. How is this done? Thanks in advance, Re: Button Coordinates in ClientRect Christian Graus8-Mar-01 18:05 Christian Graus 8-Mar-01 18:05  If you have a variable to the button CRect rc; m_myButton.GetWindowRect(&rc); otherwise CRect rc; GetDlgItem(IDC_MYBUTTON)->GetWindowRect(&rc); I believe this comes in co-ordinates relative to the dialog, in which case ClientToScreen will five you screen co-ords. If I am wrong, ScreenToClient gives you client co-ords. Christian The content of this post is not necessarily the opinion of my yadda yadda yadda. To understand recursion, we must first understand recursion.

Last Visit: 31-Dec-99 18:00     Last Update: 8-Jun-24 15:20 Refresh ᐊ Prev1...18427184281842918430184311843218433184341843518436 Next ᐅ

General    News    Suggestion    Question    Bug    Answer    Joke    Praise    Rant    Admin   

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