C / C++ / MFC

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#pragma once and #ifndef -Dy4-Jul-02 0:35 -Dy 4-Jul-02 0:35  Is there a difference between #pragma once and #ifndef _THISDEF_ #define _THISDEF_ // class declaration ... #endif ? I've always defaulted to using the #pragma once but have noticed that others tend not to use it and favour the #ifndef instead, why is this? Am I missing something very simple? Dylan Kenneally London, UK Re: #pragma once and #ifndef Alan Chambers4-Jul-02 1:16 Alan Chambers 4-Jul-02 1:16  Good point. The #ifndef statement is only included in VC++ for backwards compatibility on older compilers and (according to MSDN) the #if !defined statement is supposed to be used instead (though it gives no reason as to why? surely the #ifndef code would be more portable because of this?). The #pragma statments are platform independent compiler directives, but I'm not sure of the difference between that and #ifndef or #if !defined, if there is any at all. I would like to know for sure though . Alan. "When I left you I was but the learner, now I am the master" - Darth Vader Re: #pragma once and #ifndef Alexandru Savescu4-Jul-02 8:51 Alexandru Savescu 4-Jul-02 8:51  There is a difference between #ifndef and #if !defined. You can have some operations in the latter case. For instance: // in header.h #define A #define B // in anotherheader.h // you can use #if !defined A AND !defined B #include "header.h" #else #include "secondheader.h" #endif Best regards, Alexandru Savescu Re: #pragma once and #ifndef markkuk4-Jul-02 1:21 markkuk 4-Jul-02 1:21  The #ifndef block is portable, #pragma is non-portable by definition. Re: #pragma once and #ifndef Michael Dunn4-Jul-02 7:32 Michael Dunn 4-Jul-02 7:32  The #ifndef version has a nice advantage in that you can test whether a header has been included by checking #ifdef _THISDEF_. You can't do that with the #pragma version. And, as has been mentioned, the #ifndef way works on every compiler (for those who have to worry about portability). --Mike-- Just released - RightClick-Encrypt - Adds fast & easy file encryption to Explorer My really out-of-date homepage Sonork-100.19012 Acid_Helm OnUpdate(CCmdUI* pCmdUI) isnt called John Oliver3-Jul-02 23:47 John Oliver 3-Jul-02 23:47  Hello I have two CDialog based classes, both with toolbars, using the technique used in the MSDN MFC sample dlgcbr32 which describes how to use toolbars and status bars in dialogs by overriding these particular control classes I created the first class a few years ago and it works. I cannot get the toolbar button states to update in the 2nd class which I recently created, although the class is similar to the first. I cannot get OnUpdateButtonX(CCmdUI* pCmdUI) to be called - CDlgToolBar::OnIdleUpdateCmdUI isn't being called. Can anybody tell me what methods or messages need to be present for OnIdleUpdateCmdUI to get called. Thanks, John Re: OnUpdate(CCmdUI* pCmdUI) isnt called Michael Dunn4-Jul-02 7:34 Michael Dunn 4-Jul-02 7:34  Handle the WM_KICKIDLE message (#include "afxpriv.h" to get the definition) and call UpdateDialogControls(this, FALSE); --Mike-- Just released - RightClick-Encrypt - Adds fast & easy file encryption to Explorer My really out-of-date homepage Sonork-100.19012 Acid_Helm Re: OnUpdate(CCmdUI* pCmdUI) isnt called John Oliver5-Jul-02 0:07 John Oliver 5-Jul-02 0:07  Thanks, I've tried it but no luck. The OnKickIdle method isn't called. I'll keep trying but in case anybody has spare time here's a checklist of what's going on: -Toolbar has same resource ID as menu. The buttons have same IDs as menu items. Menu items are updated Okay but toolbar isn't -Class has CDlgTool member, which is derived from CToolbar and has OnIdleUpdateCmdUI method, which isn't called -Dlg shown non-modally m_calcDlg=new CCalcDlg(this); m_calcDlg->Setup(m_report,m_UBuckling); m_calcDlg->Create(); m_calcDlg->ShowWindow(SW_SHOWNORMAL); After this I swear I'll never write a CDialog based app. ever again! bye, John MAKEWPARAM ??? Alek3-Jul-02 23:09 Alek 3-Jul-02 23:09  I need my program to send a message which I define. as below: #define WM_MYMSG WM_USER+100; WPARAM wp; wp = MAKEWPARAM((WORD)0x200, (WORD)0x450); ::PostMessage(NULL, WM_MYMEG, wp, 0); I code a .dll to get this message and then to do something. The problem is, in the program, I get the correct wp value, but when I post the message to the .dll file, it get the wrong value. I use hook function to get this message. It get the message but the WPARAM parameter is wrong. Does anyone could give me some suggestion ? Thanks a lot. Re: MAKEWPARAM ??? 4-Jul-02 23:23 4-Jul-02 23:23  Do you call .dll in your main app?If in this way,do you change the module state in your .dll? device context question 3-Jul-02 22:32 3-Jul-02 22:32  Hello, I am new to MFC and the device context stuff. I have read some sample codes and write a simple program. It has a dialog with a button and a groupbox. When the button is pressed, an image is drawn to the groupbox by retrieving its hDC. This works fine but I don't know how to keep the image visible after refresh. How to handle this (like AutoRedraw in VB?) in VC? As a related question, I have tried to modified the program so that the dialog is a pop up window rather than the main window. I want to display the image as soon as the dialog is visible. I have tried to put the drawing code in OnInitDialog() and DoModal(), but got no luck. I guess it is the same refresh problem as above, but I am not sure. Will this problem be solved when the above refresh problem is solved? Or I need some more special handling? Thanks in advance. Re: device context question 4-Jul-02 9:19 4-Jul-02 9:19  Try to use Invalidate(TRUE) in the OnInitDialog() Version info managing 56789012343-Jul-02 22:29 5678901234 3-Jul-02 22:29  I have a large project which contains some number of VC exe and Dll projects. Threre are number of versions of this project. However, currently I don't manage Version resource and each project contains default FILEVERSION and ProductVersion 1, 0, 0, 1, empty CompanyName etc. Anybody have idea how can I manage version information (except of opening each project and setting these values manually)? Thank you. help me in MFC HoldMe3-Jul-02 22:13 HoldMe 3-Jul-02 22:13  I want to create one Class : have 2 button (starttime and stoptime) and 2 statictext (display start time and stop time) when I click to starttime button it get current time and display to statictext and stoptime button too. please help me, how to write it or send me your source. Thanks autologin with Win2000 Jerome Conus3-Jul-02 20:13 Jerome Conus 3-Jul-02 20:13  Hi !! Does anyone know how I can avoid the login window with Windows2000 ? I would like to automatically log into a specific user account without having to enter the password each time I boot win2000. Thanks for your help ! Jérôme Re: autologin with Win2000 benjymous3-Jul-02 23:20 benjymous 3-Jul-02 23:20  TweakUI[^] has an option for this (along with many other handy options) -- Help me! I'm turning into a grapefruit! Re: autologin with Win2000 Mike Nordell4-Jul-02 6:19 Mike Nordell 4-Jul-02 6:19  Have you looked at Q97597 ? Re: autologin with Win2000 Michael Dunn4-Jul-02 7:38 Michael Dunn 4-Jul-02 7:38  Open the Users control panel, it's the very first option there (uncheck "users must enter a password") --Mike-- Just released - RightClick-Encrypt - Adds fast & easy file encryption to Explorer My really out-of-date homepage Sonork-100.19012 Acid_Helm Shrinking a WAV (audio formats)? 3-Jul-02 19:03 3-Jul-02 19:03  Hi, my application plays a WAV file to sign some action. The file is 12KB and plays ca. 1 second sound. I'd like to include more sounds and reduce the size of the executable. For example for graphics I switched over to compressed TGA files and drastically (!) reduced file size. Question: Can I shrink the size of my WAVs? Perhaps WAV format do provide various (compressed) formats; and which tool should I use? For playing the sound I use this code snippet (IDR_WAVE_PING is my file linked to the resource): PlaySound(MAKEINTRESOURCE(IDR_WAVE_PING),AfxGetInstanceHandle(), SND_ASYNC + SND_RESOURCE + SND_NODEFAULT); Thanks for feedback! PS: I don't use MP3 or OGG yet, because I don't want to ship 3rd party DLLs with my exe. I'd like to have a "stand-alone" executable (at the moment). If there are any alternatives I should have a look at, please tell me. Re: Shrinking a WAV (audio formats)? Christian Graus3-Jul-02 19:38 Christian Graus 3-Jul-02 19:38  The code to play a single mp3 is here on CP, in a skinnable app example. Christian I am completely intolerant of stupidity. Stupidity is, of course, anything that doesn't conform to my way of thinking. - Jamie Hale - 29/05/2002 Re: Shrinking a WAV (audio formats)? Larry Antram3-Jul-02 20:04 Larry Antram 3-Jul-02 20:04  Including MP3 support in software pretty much requires using either Windows Media Player or paying royalties. The way that is fairly easy (and cheap) is to simply use Windows Media Player: 1. Run Visual C++ 6 and open your project 2. Select "Project" > "Add to Project" > "Components and Controls" .. then from the "Component and Controls Gallery" dialog select "Registered ActiveX Controls" then "Windows MediaPlayer", then click "Insert". 3. Then in your program: CMediaPlayer2 wmp; wmp.Create( ... ); wmp.Open( FILENAME ); wmp.Play(); -OR- Add the control to a dialog and map it to a variable and do something like: m_wmp.Open( FILENAME ); m_wmp.Play(); Viola... instant support for MP3, WMA, and all the other Windows Media Player (WMP) formats... WMP has a big fat runtime at Microsoft that you can redistribute for free for systems that don't have it. If you want something else such as everything in one EXE then you essentially have to pay royalties. For example, this company makes (what I assume) is a fairly nice royalty-based SDK: http://www.xaudio.com -- they offer both static and dynamic link libraries Regards, Larry Antram Stardust Software "I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones." -- Albert Einstein Re: Shrinking a WAV (audio formats)? Mike Nordell4-Jul-02 16:46 Mike Nordell 4-Jul-02 16:46  Larry Antram wrote: Including MP3 support in software pretty much requires using either Windows Media Player or paying royalties. What? Nonsense! There are a number of free (as in GPL) MP3 players out there. If one really cares about freedom (of patents and that crap) one should go for Ogg Vorbis (www.xiph.org). It's tried-and-proven by f.ex. the game Serious Sam, not to mention all the media players that also supports it. Well, not Microsoft of course, but that's to expect: It's free, therefore it must be communism, anti-american, cancer and the plague. All-in-one solution to both keep your money and piss MS off. It can't get much better! Re: Shrinking a WAV (audio formats)? Larry Antram4-Jul-02 17:18 Larry Antram 4-Jul-02 17:18  What I said is not nonsense. MPEG Layer-3 algorithms are patented -- and as such -- a license and royalty payments are required to use them in software. See: http://www.mp3licensing.com/help/developer.html Regards, Larry Antram Stardust Software "Why are we here? What is the purpose of life? A lot of people say it's meaningless. Nonsense. There's no use having a cosmos, no use having a universe, if you don't have an audience. The universe, needing an audience, created us. We are the meaning of life." -- Ray Bradbury [Interview, April 18, 2002] Re: Shrinking a WAV (audio formats)? 5-Jul-02 7:21 5-Jul-02 7:21  Mike Nordell wrote: There are a number of free (as in GPL) MP3 players out there. GPL is not possible in (my) commercial software, since I'm not allowed to provide the source (which GPL asks for). Also I would prefer OGG over MP3, no patent payment required. Re: Shrinking a WAV (audio formats)? Mike Nordell6-Jul-02 6:42 Mike Nordell 6-Jul-02 6:42  So, why don't you use OGG then? There's no DLL involved (unless, of course, you opt to actually compile it to a DLL).

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