C / C++ / MFC

FirstPrevNext

Re: Static Binding & Dynamic Binding :: C++ Christian Graus31-Dec-01 10:42 Christian Graus 31-Dec-01 10:42  <small><b>kuphryn wrote: </b></small><i>Lastly, I too want to implement dynimic binding if it is possible to declare *one* object of either the base class or the derived class. The following is *not correct*: ------------------------ classBase *cDynamic = new classDerived ------------------------ In other words, *virtual* would be great if there is a way to use it without having to declare two seperate classes like the example from Deitel & Deitel.</i> There is no reason you cannot do this, I did it extensively in a paint package I wrote. I created a virtual base class called CTool, or something, and then created derived classes like CToolFill, CToolRectangle, etc. My Mainframe had a member CTool*, and when I changed tools I would delete it, and make it a new CToolFill, or whatever tool was selected. Christian After all, there's nothing wrong with an elite as long as I'm allowed to be part of it!! - Mike Burston Oct 23, 2001 <Center><A href = "http://www.sonork.com" target = "_Blank">Sonork</A> ID 100.10002:MeanManOz</Center><Center>I live in <U><B>Bob's HungOut</B></U> now</center> Re: Static Binding & Dynamic Binding :: C++ valikac31-Dec-01 11:56 valikac 31-Dec-01 11:56  My original concern was not with the use of virtual function. I basically feared resource loss and performance reduction because using virtual function requires declaration of multiple classes, including one base and at least one derived. null_pointer made a good point at GameDev forums that a pointer takes up very little resource. I believe he implied that even thought virtual requires declaration of multiple class objects, doing so through pointer takes up few resources. I see the big picture is sometimes "virtual" is a necessity. It is not an option in some cases where the program has no way of knowing which function you are implying. So the question came down to the performance of static binding and dynamic binding. If there is no performance difference, then I think it is better to just use dynamic binding with inheritance. Kuphryn Re: Static Binding & Dynamic Binding :: C++ 2-Jan-02 7:56 2-Jan-02 7:56  With this: classDerived cDerived = new classDerived; classBase *cBase = &cDerived; You are creating only one object (with new). The other is a pointer variable that points to the already created object. Besides that, the following: classBase *cDynamic = new classDerived works fine. Is the same idea than before, but having one object and one pointer instead of two pointers, and is the way that is usually used. Re: Static Binding & Dynamic Binding :: C++ valikac2-Jan-02 14:22 valikac 2-Jan-02 14:22  Okay. Thanks Kuphryn Graph Sonu Kapoor31-Dec-01 5:09 Sonu Kapoor 31-Dec-01 5:09  Hi guys, how can draw graphs in vc++ like pie chart or something else ? Is there a class for that stuff ??? regards Sonu Re: Graph Ravi Bhavnani31-Dec-01 5:13 Ravi Bhavnani 31-Dec-01 5:13  Yes. http://www.codeproject.com/miscctrl/#Charting Controls. /ravi "There is always one more bug..." http://www.ravib.com ravib@ravib.com CHtmlView 31-Dec-01 4:36 31-Dec-01 4:36  Is it possible to get the HTML-Code from the Site wich is shown in CHtmlView and to use it in the program (extracting Links etc.) or to change the shown Site dynamically out of the Mfc-program. shojo is back Re: CHtmlView Philip Patrick1-Jan-02 2:49 Philip Patrick 1-Jan-02 2:49  There are many ways to do it. If you want to have a simple text with ALL code on the page, you can use the TextRange of tag. But if you are processing the HTML, I mean extracting links, images, tables, etc., I suggest to use MSHTML library, it has good interfaces that do parsing for you. Too big thing to discuss, so here is the link that talks about MSHTML on MSDN Web site: MSHTML reference Philip Patrick "Two beer or not two beer?" <shakesbeer> Web-site: www.saintopatrick.com call a function from more then 1 project Aviv Halperin31-Dec-01 4:23 Aviv Halperin 31-Dec-01 4:23  I'm trying to call a function from more then 1 project . I do the following: in one project i wrote: int ChosenPort; extern int GetPort(){return ChosenPort;} from another i try to call the function: int ChosenPort; ChosenPort=GetPort(); I get a linking error: error LNK2001: unresolved external symbol _GetPort please help me if you can. Thanks heaps. Aviv. avivhal Re: call a function from more then 1 project Chris Losinger31-Dec-01 4:32 Chris Losinger 31-Dec-01 4:32  you have many options. here are a few: 1. copy the source files (and any appropriate header files) from the project where "GetPort" currently lives into the new project. pro: it's easy. con: duplication of source code. 2. put the files for GetPort into a new static library project and have each of your projects link to that library. pro: source for GetPort is in one place. con: takes a few minutes to set up. 3. put the files for GetPort into a new DLL project and have each of your projects use that DLL. pro: source for GetPort is in one place. con: takes a few minutes to set up; you have to ship a DLL. i always go for option 2. -c Smaller Animals Software, Inc. Loading function from an exe... Rickard Andersson2031-Dec-01 3:08 Rickard Andersson20 31-Dec-01 3:08  I can't load a function from my apps exe from one of my apps DLs: (This code is from one article here on CodeProject I think...) // I think it just to do the same when loading a function from a DLL.. but noup static HINSTANCE hinstDLL; typedef BOOL (CALLBACK *inshook)(); inshook instkbhook; hinstDLL = LoadLibrary((LPCTSTR) "hodll.dll"); instkbhook = (inshook)GetProcAddress(hinstDLL, "installhook"); instkbhook(); The error is that Explorer crash... how to load a function from my exe? It's a global function ------------------------------ ©0d3 ©®4©k3® - That's me! ------------------------------ Re: Loading function from an exe... BlackSmith31-Dec-01 5:33 BlackSmith 31-Dec-01 5:33  1. Did you put the DLL same dir as the EXE ( If the explorer crashes you must be useing WinMe or earlier...)? Did you exported it right? DLL: extern "C" { void myFunc(void) { /*Function body*/ } }/*extern "C" closing clauses*/ 3. Check 'LoadLibrary()' and 'GetProcAddress()' return value If it's 'NULL' The DLL/Function isn't found Good Luck --BlackSmith-- "With the help of all mighty", 2001, Me. MFC Extention DLL - Exporting classes..... BlackSmith31-Dec-01 2:49 BlackSmith 31-Dec-01 2:49  The MSDN suggested: The DLL: ******** #ifndef _INCLUDED_MYCLASS_H_ #define _INCLUDED_MYCLASS_H_ #undef AFX_DATA #define AFX_DATA __declspec(dllexport) class CMyClass : public CObject { DECLARE_MESSAGE_MAP() //Class definition... // // }; #undef AFX_DATA #define AFX_DATA #endif//_INCLUDED_MYCLASS_H_ ************************************************************ In the my app: ************** #ifndef _INCLUDED_MYCLASS_H_ #define _INCLUDED_MYCLASS_H_ #undef AFX_DATA #define AFX_DATA __declspec(dllimport) class CMyClass : public CObject { DECLARE_MESSAGE_MAP() //Class definition... // // }; #undef AFX_DATA #define AFX_DATA #endif//_INCLUDED_MYCLASS_H_ The DLL compiles fine, but my app gets unresoulved external about all used methods. I assume, this for not writing "class AFX_EXT_CLASS MyClass..." but when I do (DLL or my app) I get: "error C2487: 'messageMap' : member of dll interface class may not be declared with dll interface" What todo? Please be specific... 10X! --BlackSmith-- "With the help of all mighty", 2001, Me. Re: MFC Extention DLL - Exporting classes..... Nnamdi Onyeyiri31-Dec-01 7:18 Nnamdi Onyeyiri 31-Dec-01 7:18  I use the AFX_EXT_CLASS and it exports the class fine. ================================================== The Eclypse menu from resource redrawing? Kuniva31-Dec-01 2:40 Kuniva 31-Dec-01 2:40  I have an MFC dialog application and in its properties i assign it a menu. I thought "wow this is easy, i just make a menu and stick it on the dialog, i dont even have to write any code for it". But then i wanted to disable an item and found a problem. this is what i have: void CMyDlg::OnUpdateMyItem(CCmdUI* pCmdUI) { pCmdUI->Enable(FALSE); } This disables the menuitem BUT! it doesn't show it disabled. It's like it does it in the background without redrawing the menu. Can anyone tell me how to work with the pointer and all so its updated correctly?? Thanks (PS: i tried CMyDlg::DrawMenuBar(); , no effect) Kuniva Re: menu from resource redrawing? 567890123431-Dec-01 4:37 5678901234 31-Dec-01 4:37  You cannot use ON_UPDATE_COMMAND_UI in dialog. You should directly enable/disable menu items using CMenu class or use some tricks described in http://www.codeguru.com/dialog/index.shtml, CommandUI section. Re: menu from resource redrawing? Michael Dunn31-Dec-01 7:09 Michael Dunn 31-Dec-01 7:09  UPDATE_COMMAND_UI doesn't work automagically in dialogs. You need to add a handler for the MFC message WM_KICKIDLE, and in that handler, call: UpdateDialogControls(this, FALSE); --Mike-- My really out-of-date homepage Buffy's on. Gotta go, bye! Sonork - 100.10414 AcidHelm Big fan of Alyson Hannigan. How do i add the handler? Kuniva1-Jan-02 3:37 Kuniva 1-Jan-02 3:37  I tried to add the handler by clicking right on my dialog class and slecting Add Message Handler, but i cant seem to define "WM_KICKIDLE". How do i add a handler for a custom message like that? Happy Newyearrrrrrrrrrrrrrrr!!!!!!!!!!!!!!!!!!!!! :p Kuniva - Also a big Buffy fan, but mostly for Eliza Dushku (Faith) TextWidth and GDI+ (Anders is learning GDI+ part 3) Anders Molin31-Dec-01 1:51 Anders Molin 31-Dec-01 1:51  With the good old GDI I have always used GetTextExtentPoint32() to get the width of a text string on the current DC. Now I'm am playing around with Gdiplus::Graphics.DrawString(), but I can't find any function that tell me how many pixels my string is going to be (text width) Any ideas? - Anders Money talks, but all mine ever says is "Goodbye!" Re: TextWidth and GDI+ (Anders is learning GDI+ part 3) Andreas Hallberg31-Dec-01 3:51 Andreas Hallberg 31-Dec-01 3:51  You may have some success with the overloaded methods: Gdiplus::Graphics::MeasureString(...) OR Gdiplus::Graphics::MeasureDriverString(...) /Andreas Re: TextWidth and GDI+ (Anders is learning GDI+ part 3) Anders Molin1-Jan-02 3:35 Anders Molin 1-Jan-02 3:35  Thanks a lot - Anders Money talks, but all mine ever says is "Goodbye!" OO concept query sysdeamon31-Dec-01 1:38 sysdeamon 31-Dec-01 1:38  Hi, i am new to C++ & Object Oriented concepts. I came across the 'inheritence' chapter in my C++ book & have the following question. Can a template class be used as a base class ? thankyou all for replying. sysdeamon Re: OO concept query Aaron Schaefer31-Dec-01 4:17 Aaron Schaefer 31-Dec-01 4:17  Yes!! Re: OO concept query Alvaro Mendez31-Dec-01 5:56 Alvaro Mendez 31-Dec-01 5:56  I agree! Re: OO concept query Michael Dunn31-Dec-01 7:11 Michael Dunn 31-Dec-01 7:11  Yes, for example: class CKewlControl : public CWindowImpl<CKewlControl, CStatic> --Mike-- My really out-of-date homepage Buffy's on. Gotta go, bye! Sonork - 100.10414 AcidHelm Big fan of Alyson Hannigan.

Last Visit: 31-Dec-99 18:00     Last Update: 12-May-24 0:01 Refresh ᐊ Prev1...17632176331763417635176361763717638176391764017641 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.