BN_DOUBLECLICKED - C / C++ / MFC Discussion Boards

Jörgen Sigvardsson3-Dec-05 14:20

3-Dec-05 14:20

You cannot create child controls in the constructor, because the window is not created yet. You see, the CFormView object is nothing but a wrapper around a HWND (window handle). You will have much better luck if you create the child controls in OnInitialUpdate() (that is a virtual method which you can override, and is found in the classwizard).

All MFC window/control* classes are only wrappers around window handles, they are not windows themselves. They merely present a C++-friendly interface (some may disagree with this) to the messaging protocols which the window supports.

--
Pictures[^] from my Japan trip.

-- modified at 8:56 Sunday 4th December, 2005

Re: Using CFormView in SDI app

Gary R. Wheeler4-Dec-05 2:53

Gary R. Wheeler

4-Dec-05 2:53

Jörgen Sigvardsson wrote:
They merely present a C++-friendly interface (some may disagree with this)

Aw, don't spoil his fun, Jörgen Big Grin | :-D

Software Zen: delete this;

Re: Using CFormView in SDI app

RoyceF4-Dec-05 6:24

RoyceF

4-Dec-05 6:24

Yes, I understand all that. It is the creation of the CFormview window that I am having trouble with. How and when do I create it? Must it be a child of a CFrameWnd? Can it be a child of another CFormView?

How to list the connected USB devices or COM port

BaySeagull3-Dec-05 1:34

BaySeagull

3-Dec-05 1:34

Hi, everyone! Big Grin | :-D

My current project is an application to control the 3-axis table for the optical microscope. The each stepping motor can be controlled by the serial communication port using the ASCII text format.

Now, I would like to know which COM port is connected or not.
Is there any method to list the connected USB or COM port?

BaySeagull

How to generate a bmp file

Ming Luo3-Dec-05 0:10

Ming Luo

3-Dec-05 0:10

Hi all:
I am writing a program which is a opengl like library. Finally I need to generate a bmp file to display the result. Does anybody know how to make a bmp file from c++ please???
Thanks a lot

Asura

Re: How to generate a bmp file

BaySeagull3-Dec-05 1:16

BaySeagull

3-Dec-05 1:16

Well, I guess a lot of examples you can get through the internet.

Anyway, the followings are my humble example.

<br />
<br />
BITMAPFILEHEADER bfh;<br />
BITMAPINFOHEADER bih;<br />
char* pBuffer; // please provide the bitmap.<br />
<br />
<br />
			bfh.bfType = ((WORD) ('M' << 8) | 'B');; <br />
			bfh.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + lBuffer; <br />
			bfh.bfReserved1 = 0; <br />
			bfh.bfReserved2 = 0; <br />
			bfh.bfOffBits = sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER); <br />
<br />
			bih.biSize = sizeof(BITMAPINFOHEADER);<br />
			bih.biWidth = pvih->bmiHeader.biWidth;<br />
			bih.biHeight = pvih->bmiHeader.biHeight;<br />
			bih.biPlanes = pvih->bmiHeader.biPlanes;<br />
			bih.biBitCount = pvih->bmiHeader.biBitCount;<br />
			bih.biCompression = BI_RGB;<br />
			bih.biSizeImage = 0; <br />
			bih.biXPelsPerMeter = 0;<br />
			bih.biYPelsPerMeter = 0;<br />
			bih.biClrUsed = 0;<br />
			bih.biClrImportant = 0;<br />
<br />
			CFileDialog dlg(FALSE, _T("bmp"), NULL,<br />
				OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,<br />
				"BMP (*.bmp)|*.bmp|All Files (*.*)|*.*||");<br />
				<br />
			if(dlg.DoModal()==IDOK)<br />
			{<br />
				CFile file(dlg.GetPathName(), CFile::modeCreate|CFile::modeWrite);<br />
				file.Write(&bfh, sizeof(BITMAPFILEHEADER));<br />
				file.Write(&bih, sizeof(BITMAPINFOHEADER));<br />
				file.Write(pBuffer, lBuffer);<br />
				file.Close();<br />
			}	<br />

BaySeagull

Saving a Bitmap from Window Enviornment

Jeeva Mary Varghese2-Dec-05 22:15

Jeeva Mary Varghese

2-Dec-05 22:15

Hai,
Please tell me that how to save a picture from client enviornment(CFormView) as Bitmap.

regards,
Jeeva

BN_DOUBLECLICKED

LeeeNN2-Dec-05 20:02

LeeeNN

2-Dec-05 20:02

Hi, suprise! BN_DOUBLECLICKED wouldn't work! I want a button when single click do one thing, and when double clicked do another thing. but it never hit OnButtonDoubleclicked().
I search on Web, some one said, should change the button style to BS_NOTIFY, then I did check this style on property page. It made no difference.

Any one can help?

Thank you in advance. Confused | :confused:

Re: BN_DOUBLECLICKED

Branislav2-Dec-05 23:31

Branislav

2-Dec-05 23:31

http://www.codeproject.com/buttonctrl/doubleclick.asp[^]

Re: BN_DOUBLECLICKED

LeeeNN3-Dec-05 6:34

LeeeNN

3-Dec-05 6:34

Yes I went there before. I don't like the way to check double click. and I tried to check Notify option in property page, OnDoulbleClick() still could not be called. I still think there should be a better to do it. otherwise Wizzard should remove DoubleClicked notification from CButton.
MSDN says BS_USERBUTTON can get BN_DOUBLECLICKED notification. how to create BS_USERBUTTON?
Roll eyes | :rolleyes:

Re: BN_DOUBLECLICKED

Branislav4-Dec-05 20:51

Branislav

4-Dec-05 20:51

Did you select Notify in Puch Button Properties - Styles dialog box?

Re: BN_DOUBLECLICKED

Owner drawn4-Dec-05 22:23

Owner drawn

4-Dec-05 22:23

Try to subclass the button and handle the double click

<marquee direction="up" height="30" scrolldelay="1" step="1" scrollamount="1" hspace="0" vspace="0">
--Owner Drawn
--Nothing special
--Defeat is temporary but surrender is permanent
--Never say quits
--Jesus is Lord

LNK2001 error

QuickDeveloper2-Dec-05 18:20

QuickDeveloper

2-Dec-05 18:20

I am converting an appln to unicode.

I use the code as follows

HtmlHelp(pWnd->GetSafeHwnd(), strHelpPath+="::/Popuptext.txt",
HH_DISPLAY_TEXT_POPUP, (DWORD)&popup);

but it throws up the following error

ExportDlg.obj : error LNK2001: unresolved external symbol _HtmlHelpW@16
ImportDlg.obj : error LNK2001: unresolved external symbol _HtmlHelpW@16
ReleaseUMinSize/ImportExport.dll : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.

when i include HtmlHelp.lib it says

LINK : warning LNK4098: defaultlib "LIBCMT" conflicts with use of other libs; use /NODEFAULTLIB:library

i have the htmlhelp.lib in current directory

what do i need to remove this error??

thanx in advance

warning LNK4098

sunit52-Dec-05 18:49

sunit5

2-Dec-05 18:49

actually u r linking with incompatible libraries for example
if you compiled one file to use one kind of run-time library and another file to use another kind (for example, single-threaded versus multithreaded) and tried to link them, you’ll get this warning.

You should compile all source files to use the same run-time library.
-- modified at 0:51 Saturday 3rd December, 2005

how to display a transparent gif picture

blackeye20042-Dec-05 15:57

blackeye2004

2-Dec-05 15:57

how to display a transparent gif picture

Can C++ DLL developed with Visual Studio .NET 2003 be used by Delphi, Borland C++ etc

FFKONG2-Dec-05 14:22

FFKONG

2-Dec-05 14:22

Can a C++ DLL developed with Microsoft Visual Studio .NET 2003 be used by Delphi, Borland C++ and other object-oriented languages? I am hoping to write a C++ DLL with ADO and CAsynSocket capability wrapped in some classes. Would there be any problem with Delphi, VB.NET, Borland C++ etc., e.g. name mangling due to different compiler vendors, if I export the classes in the C++ DLL? Can the Delphi, VB.NET, Borland C++ access and those exported classes? Thanks.

Re: Can C++ DLL developed with Visual Studio .NET 2003 be used by Delphi, Borland C++ etc

Jörgen Sigvardsson2-Dec-05 14:53

Jörgen Sigvardsson

2-Dec-05 14:53

If you want cross platform/language, without giving into .NET, I advise you to go the COM route, as that's the only common denominator between the languages you mention (AFAIK).

--
Pictures[^] from my Japan trip.

Re: Can C++ DLL developed with Visual Studio .NET 2003 be used by Delphi, Borland C++ etc

FFKONG2-Dec-05 16:50

FFKONG

2-Dec-05 16:50

So meaning that in this case I should wrap the C++ classes in a COM instead of a C++ DLL? Can Delphi, Borland C++ and other OOP languages use COM? What about a C DLL developed with Microsoft Visual Studio .NET? Can Delphi, Borland C++, VB .NET use the C DLL without any issue? Thank you very much.

Re: Can C++ DLL developed with Visual Studio .NET 2003 be used by Delphi, Borland C++ etc

Jörgen Sigvardsson2-Dec-05 22:08

Jörgen Sigvardsson

2-Dec-05 22:08

Basically all languages and environments implemented for the Windows environmnt has support for COM, including C. Smile | :)

--
Pictures[^] from my Japan trip.

Re: Can C++ DLL developed with Visual Studio .NET 2003 be used by Delphi, Borland C++ etc

Gary R. Wheeler3-Dec-05 1:47

Gary R. Wheeler

3-Dec-05 1:47

If you wrap your C++ classes in a 'C'-style interface, then Delphi, etc. would be able to use your DLL. Note that you lose the notion of 'classes' then. Here's an example:

// your class:
class MyClass {
public:
  MyClass(int arg1,double arg2);
  ~MyClass();
  void Function1(int arg3);
};
// DLL interface:
extern "C" {
  typedef void *MyClass;
  MyClass *MyClass_constructor(int arg1,double arg2);
  void MyClass_destructor(MyClass *instance);
  void MyClass_Function1(MyClass *instance,int arg3);
};

The DLL interface defines a 'constructor' function that will return a pointer to a MyClass object. The remaining functions take one of those pointers as their first argument. Note that you will need to be careful to explicitly the destructor function, since the user of the DLL is not C++, and doesn't know to call destructors when an object goes out of scope or is deleted.

Software Zen: delete this;

Re: Can C++ DLL developed with Visual Studio .NET 2003 be used by Delphi, Borland C++ etc

Jörgen Sigvardsson3-Dec-05 9:57

Jörgen Sigvardsson

3-Dec-05 9:57

That's doable too. The good thing about COM though, is that you get marshalling for free, should you want to do outproc stuff.

--
Pictures[^] from my Japan trip.

Re: Can C++ DLL developed with Visual Studio .NET 2003 be used by Delphi, Borland C++ etc

FFKONG3-Dec-05 13:39

FFKONG

3-Dec-05 13:39

Hi Jorgen, can I wrap the ADO (a COM) and MFC CAsyncSocket class capability into a COM? Is it workable if I develop the COM in Visual C++ and use the COM in Delphi, Borland C++ and other non-OOP languages? Any special codes that I need to add into the COM source so that it can cater for a specific language, eg a code section for Delphi and another code section for Borland C++? I would greatly appreciate if you can provide me some sample codes for developing COM in Visual C++ or any reference that I can refer to. Thank you very much.

Re: Can C++ DLL developed with Visual Studio .NET 2003 be used by Delphi, Borland C++ etc

Jörgen Sigvardsson3-Dec-05 14:34

Jörgen Sigvardsson

3-Dec-05 14:34

I must admit that I have not used Delphi myself, but I do know that it supports ActiveX controls. In order to do that, there must be support for COM¹. Borland C++ does have support for COM, that I know for sure.

COM is essentially a set of specifications. COM is built upon the notion that all components are communicated with through an interface. How the interface is represented in memory, is dictated by COM. Hence you will not need to provide different interfaces or implementations for each client language (Delphi, Borland C++, .NET-languages, etc). Write once in Visual C++ (or even Borland C++, VB6, .NET-languages, you name it), and use it in all COM capable client languages. Despite what Microsoft says, there were solutions for cross language development prior to .NET. Wink | ;)

I should warn you though that COM has a rather steep learning curve. But in all honesty, books like Essential COM[^], and ATL Internals[^] makes that learning curve much flatter. ATL by the way, is a C++ class library, which takes care of much of the "boiler plate coding" needed for COM. It allows you to use wizards, as well as hand wire COM stuff quite easily. Should you chose the COM route, please use ATL. It'll spare your fingers from all that typing. Smile | :)

¹ Well, to be honest, there doesn't have to be support for COM. It could be that all COM/ActiveX details are embedded into the language itself, shielding the programmer from COM. I doubt that though, because that would be utterly stupid, should the COM and ActiveX specifications change.

--
Pictures[^] from my Japan trip.

Re: Can C++ DLL developed with Visual Studio .NET 2003 be used by Delphi, Borland C++ etc

Gary R. Wheeler4-Dec-05 1:56

Gary R. Wheeler

4-Dec-05 1:56

Agreed. I brought up my suggestion in case FFKONG needed something quick and simple (i.e. didn't have time to learn COM).

Software Zen: delete this;

Serial Port communication

picazo2-Dec-05 12:58

picazo

2-Dec-05 12:58

Hi all,

this is my first time using port communcation, so I am a bit confused. I have read the msdn and several articles, but I still don't understand exactly how to do what I want.

Basically, I have a peripheral on my machine that I want to send messages to and receive messages from. I downloaded the CSerialCom[^] library from codeproject, so reading and writing is not a problem.

The problem is that the system requires programatic-management of control flow mechanish (DTR/DSR), which means that I must assert the DTR to get the peripheral's attention, and then I must wait for the DSR assertion before I can transmit data.

Can someone provide a demo that shows how to communicate with a peripheral with these contraints?

Thanks,

-----------------
Genaro

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