Re: Subclassing - Better explanation of problem - C / C++ / MFC Discussion Boards

Combobox dropdown showing wrong selection

Richard Jones19-Mar-03 2:49

19-Mar-03 2:49

I have a standadrd combobox populated with a font's 256 characters.
When the user selects one, the list closes, and the correct value is shown in the combo line.

If the user selects a character with a double (ie 'A' and 'a'), the next
time the list drops down, the FIRST one ('A') is shown in the combo line, not the selected one ('a').

As long as the selected value is unique, there is no problem.

I have tried using OnDropDown to reset the CurSel to the proper index, GetLBText for the string, etc. and nothing works.

ShellExecuteEx & WaitForSingleObject

Brian Delahunty19-Mar-03 2:21

Brian Delahunty

19-Mar-03 2:21

Hey.

Having a small problem launching an app using ShellExecuteEx and using WaitForSingleObject afterwards....

If I use WaitForSingleObject the app launches but seems to freeze until I close my program... If I don't use WaitForSingleObject then it runs perfectly fine...

C++

SHELLEXECUTEINFO ShExecInfo = {0};
ShExecInfo.cbSize = sizeof(SHELLEXECUTEINFO);
ShExecInfo.fMask = SEE_MASK_NOCLOSEPROCESS;
ShExecInfo.hwnd = NULL;
ShExecInfo.lpVerb = NULL;
ShExecInfo.lpFile = ".\\J2EE_SDK_1.3.1\\setupJ2EE.exe";		
ShExecInfo.lpParameters = "";	
ShExecInfo.lpDirectory = NULL;
ShExecInfo.nShow = SW_SHOW;
ShExecInfo.hInstApp = NULL;	
if(!ShellExecuteEx(&ShExecInfo))
{
    // I'm doing somethng in here
}

// Hide window until the process returns
this->ShowWindow(SW_HIDE);
WaitForSingleObject(ShExecInfo.hProcess,INFINITE);

The program I'm launching is the setup for the Java Enterprise Enviornment [An InstallShield v 5.10 setup file.]

Any ideas???

Regards,
Brian Dela Smile | :)

Run naked in the snow until you're sweating like a stuck pig and can't seem to catch your breath. When the flu becomes pneumonia, they can cure that with a shot. - Roger Wright

Re: ShellExecuteEx & WaitForSingleObject

Joel Lucsy19-Mar-03 2:37

Joel Lucsy

19-Mar-03 2:37

try something like

<br />
MSG msg;<br />
while (WaitForSingleObject( ShExecInfo.hProcess, 0 ) != WAIT_OBJECT_0)<br />
{<br />
    while (PeekMessage( &msg, 0, 0, 0, PM_REMOVE ))<br />
    {<br />
        TranslateMessage( &msg );<br />
        DispatchMessage( &msg );<br />
    }<br />
}<br />

Joel Lucsy

Re: ShellExecuteEx & WaitForSingleObject

Brian Delahunty19-Mar-03 2:45

Brian Delahunty

19-Mar-03 2:45

Excellent... Works perfectly Big Grin | :-D

Thanks

Regards,
Brian Dela Smile | :)

Run naked in the snow until you're sweating like a stuck pig and can't seem to catch your breath. When the flu becomes pneumonia, they can cure that with a shot. - Roger Wright

Button and Text control

wavewave19-Mar-03 2:07

wavewave

19-Mar-03 2:07

How to create a Button and Text(output only) controls in a Microsoft C 6.0 DLL without using MFC nor class?

Is there any reference coding available?

Thanks.

Subclassing

Mathias S.19-Mar-03 1:24

Mathias S.

19-Mar-03 1:24

I need a class that creates the controller I need dynamically. When this class is created it loads up some data from a file and depending on what it says in that file the controller should be a CListCtrl or a CEdit.

So I thought I create a dummy controller inherited directly from CWnd let my dialog creates it and then this controller will load the data in the file and then creates the CListCtrl or CEdit and subclass it to my own controller.

It should work, but I don't get it to. I think I might have misunderstood some things with subclassing.

In OnInitDialog I have

// Created Dynamically for now
m_DummyController.create( this , CRect( x , y, w , h ) , 1 );
And then DummyController is doing its stuff (checking what kind of controller it wants to transform into)

CMyDummyCtrl::BeAEditCtrl()
{
	CEdit pEdit = new CEdit;
		
	// Should I really run this ?
	if( pEdit->create( WS_CHILD | WS_BORDER | WS_VISIBLE , CRect( x , y, w , h ) , GetParent() , 0 ) )
	{
		pEdit->SubclassWindow( this->GetSafeHwnd() );
	}
}

This doesn't work at all. I tried different versions of it so I’m properly going at this problem the wrong way. So any help with be good.

/Mathias

Re: Subclassing

Joan M19-Mar-03 3:54

Joan M

19-Mar-03 3:54

Your problem is about "scope", you've declared a CEdit variable (pEdit) inside a function, and that variable is destroyed when you leave the same function...

in order to solve it, declare your CEdit inside the class and then use it from any function in the same class, the CEdit will exist while the owner class exists too...

Hope this helps...

Re: Subclassing - Better explanation of problem

Mathias S.19-Mar-03 4:19

Mathias S.

19-Mar-03 4:19

There where some typos in the code.

CEdit pEdit = new CEdit; // would also give a Compile error 
// It should have been
CEdit* pEdit = new CEdit;

So it was a pointer. But the problem is that it crashes in subclassWindow(...)

A better way of explaining my problem is.
I Have my Dummy controller an that controller then creates a new controller ( CEdit ) and displays it inside CMyDummyCtrl and the CEdit controller is taking up the same place that CMyDummyCtrl and all Messages sent to CMyDummyCtrl should always be relayed to CEdit since CMyDummyCtrl isn't really doing anything
That is what I want to do. And I thought I was able to do that with subclassWindow(..)
but I don't get it to work.

Events fired by CHotKeyCtrl

dabs19-Mar-03 1:00

dabs

19-Mar-03 1:00

Has anyone tried capturing events fired by CHotKeyCtrl? I would like to know when the user selects a new hotkey but I can't seem to find any info on that. Anyone?

Wenn ist das Nunstück git und Slotermeyer? Ja! Beierhund das oder die Flipperwaldt gersput!

Re: Events fired by CHotKeyCtrl

Michael Dunn19-Mar-03 6:46

Michael Dunn

19-Mar-03 6:46

It sends an EN_CHANGE message just like an edit control.

--Mike--
THERE IS NO THERE IS NO BUT THERE IS MAGIC PIXIE DUST BUSINESS GENIE CODE PROJECT

Homepage | RightClick-Encrypt | 1ClickPicGrabber
"Which comes first, the bug or the stress?" -- Chris Maunder

Visual Source Safe - Help Need Quickly!!

IrishSonic19-Mar-03 0:58

IrishSonic

19-Mar-03 0:58

Hiya can anyone show me quickly how to use Visual Source Safe 6.0. I have a project that I want to make changes to and then detect in VSS and make the necessary changes...
Also does anyone have a tutorial on VSS??

Thanks a million,
grahamoj.

Using Classes created in C++ in a VB.Net program

Brynn19-Mar-03 0:43

Brynn

19-Mar-03 0:43

Heres the scenrio I would like to access a set of library functions that were originally designed to be called from C (they are in fact the Sybase Open Client libraries), I know there are OLE and ODBC drivers etc but they constrain what you can do.

So the idea is to write some "glue" to go between the C interfaces of open client and VB.NET.

I believe that there is no reason why I cannot do this so I tried to just test this out and wrote a simple class in C++, compiled it as a DLL and tried to link it in as a reference to my VB program. This returns an error saying that my dll is not a .Net assembly.

I have tried to find something relevant in all the documentation that I have available but there is just so much I have been unable to find what I need.

Can someone throw me a bone here before I go totally bald. Confused | :confused:

Thanks

Re: Using Classes created in C++ in a VB.Net program

AlexO19-Mar-03 3:36

AlexO

19-Mar-03 3:36

try this
Programming with Managed Extensions for Microsoft Visual C++ .NET

How to open a browser window

Jump_Around19-Mar-03 0:38

Jump_Around

19-Mar-03 0:38

I want to create a piece of code which will be opening a new browser window displaying given Url.

It seems to be very easy, but I don't have idea how to do this.

Please help Poke tongue | ;-P

Re: How to open a browser window

Johnny ²19-Mar-03 0:45

Johnny ²

19-Mar-03 0:45

ShellExecute (NULL, "open", url, NULL, NULL, SW_SHOW);

Re: How to open a browser window

Jump_Around19-Mar-03 1:10

Jump_Around

19-Mar-03 1:10

Great thank you.

Could you give me a hint how to open this url in a new browser window, not in the already opened one.

Thanks in advance

Re: How to open a browser window

savaNT19-Mar-03 4:35

savaNT

19-Mar-03 4:35

ShellExecute (NULL, "open", "iexplore.exe" , "http://www.etc.com", NULL, SW_SHOW);
1) Better to type _T("string") instead "string"
2) The 3rd param is the program to "open" and the 4th param is the parameter for the 3rd
3) If you type
ShellExecute (NULL, "open", url_1, NULL, NULL, SW_SHOW);
Sleep(2000); // 2 seconds
ShellExecute (NULL, "open", url_2, NULL, NULL, SW_SHOW);
the web pages (1st,then 2nd) will be show on the same browser window.
The code line I suggest you will open multiple windows
4) Look in MSDN for "ShellExecute", in order to understand last parameter
(you can combine more atributes using '|' operator)
5) If your URL is not a constant string, make a variable:
CString strUrl;
...
ShellExecute (NULL, "open", (LPCTSTR)strUrl, ......)

Looking for a VC++ Sample for Wake up on LAN (WOL)?

Ralph18-Mar-03 23:48

Ralph

18-Mar-03 23:48

Hallo!
Is there anybody how knows, or even has, a VC++ sample (or a link for more details) how to create and send a MagicPacket to create a "Wake up on lan" event on an other PC!

Thanks a lot!
Ralph

Re: Looking for a VC++ Sample for Wake up on LAN (WOL)?

Scott H. Settlemier19-Mar-03 1:22

Scott H. Settlemier

19-Mar-03 1:22

Here's a short program [^]for doing this on linux. (discussed here[^])
It should be easy to port.

Re: Looking for a VC++ Sample for Wake up on LAN (WOL)?

Anonymous19-Mar-03 6:36

Anonymous

19-Mar-03 6:36

Thanks for your quick reply!
I'll try to code this in MFC and W2K, may be it works!

Wink | ;)

Ralph

references VS. data members

Makover18-Mar-03 23:37

Makover

18-Mar-03 23:37

Suppose I have class, what would be better - using references to deliver message between the member functions or declare the delivered objects as data members of the class?

class bla{
   public:
      ...
   private:
      Worker w; 
};

void func1() {
... 
func2(w); 
...
}


void func2(Worker& w) {
...
}

-----------------------
But what did I do?

Re: references VS. data members

Dave Bryant19-Mar-03 8:49

Dave Bryant

19-Mar-03 8:49

There is no one correct answer to this. In your first case, class bla actually owns the Worker object, and so this is apropriate if it is part of an aggregation relationship. The second case is appropriate where you do not own the object, but need to operate on it. Of course, if most of the class methods need a reference to the Worker object, you could declare a reference, not an object, inside the bla class.

If you can be more specific about what you are doing i might be able to give a more specific answer.

Dave

Re: references VS. data members

Makover19-Mar-03 8:55

Makover

19-Mar-03 8:55

Thank You Dave.

There is no "specific problem". I was just wondering Roll eyes | :rolleyes:

What you said seems very legitimate to me. In fact, I suspected this should be the consideration I should take. Do you have any idea if there is any difference in performance?

Thanks again Rose | [Rose]

-----------------------
But what did I do?

Re: references VS. data members

Dave Bryant19-Mar-03 9:09

Dave Bryant

19-Mar-03 9:09

There is a difference in performance, but the vast majority of the time it is irrelevant. Member functions actually have a hidden first parameter, which is the 'this' pointer. To access a member variable, they must retrieve the value at the address which is a known offset from this pointer.

If the variable is passed in as a parameter, it can be accessed more directly, because it is at a known address on the stack (or rather a known address relative to the current top of the stack). On most architectures, this will mean that accessing a member variable will take 1 instruction more than accessing a parameter - fairly inconsequential.

Dave

Analyzer of heads

calgonit18-Mar-03 22:53

calgonit

18-Mar-03 22:53

I need to make an analyzer of heads of methods in Visual C++, that is given a head of a method in a CString of the following way:

BOOL FichControl::CopyFile( const char *lpSrcFilename, const char *lpDestFilename, int nBuffersize )

I need to obtain each SubString that conforms the head (BOOL, FichControl, CopyFile, const char, *lpSrcFilename, ...)

Exists some form to do this, that is not crossing the CString of principle to aim character to character?

Thank you very much!

PD: Sorry for my bad English.

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