function pointer on classfunctions - C / C++ / MFC Discussion Boards

Jack Puppy12-Jun-05 0:16

12-Jun-05 0:16

I found this in one of my old libraries. Can't say that it's foolproof though as I don't remember using it much. (I made a function for each system class, but primarily only used AfxIsEdit, AfxIsComboBox)

BOOL AfxIsDialogBox(HWND hWnd)
{
	return (AfxIsSystemClass(hWnd, _T("#32770")));
}

BOOL AfxIsSystemClass(HWND hWnd, LPCTSTR lpszSystemClassName)
{
	// Bad window?
	ASSERT(::IsWindow(hWnd));
	if (!::IsWindow(hWnd))
		return FALSE;

	// Bad class name?
	ASSERT(AfxIsValidString(lpszSystemClassName));
	if (!AfxIsValidString(lpszSystemClassName))
		return FALSE;

	// Get the classname for the window and compare to the system class name
	TCHAR szClassName[100];
	return (::GetClassName(hWnd, szClassName, 100) && _tcsicmp(szClassName, lpszSystemClassName) == 0);
}

Pssst. You see that little light on your monitor? That's actually a government installed spy camera. Smile and wave to big brother!

Re: Win32: IsDialog(HWND)?

Jörgen Sigvardsson12-Jun-05 2:57

Jörgen Sigvardsson

12-Jun-05 2:57

Jack Squirrel wrote:
return (AfxIsSystemClass(hWnd, _T("#32770")));

That may not always work, as you can superclass dialogs. Frown | :(

--
An eye for an eye will only make the world blind.

Re: Win32: IsDialog(HWND)?

peterchen12-Jun-05 3:49

peterchen

12-Jun-05 3:49

How?
(Couldn't find anything in thew Dialog Box API)

Pandoras Gift #44: Hope. The one that keeps you on suffering.
aber.. "Wie gesagt, der Scheiss is' Therapie"
boost your code || Fold With Us! || sighist | doxygen

Re: Win32: IsDialog(HWND)?

Jörgen Sigvardsson12-Jun-05 5:21

Jörgen Sigvardsson

12-Jun-05 5:21

How to subclass, or how to detect subclassed dialogs? The answer to the first one is in the ATL library. I stumbled upon it one day as I was making my own dialog windows. The answer for the second question is: I don't know. Dialogs are tricky, that's for sure.

--
An eye for an eye will only make the world blind.

Re: Win32: IsDialog(HWND)?

Jack Puppy12-Jun-05 4:22

Jack Puppy

12-Jun-05 4:22

Jörgen Sigvardsson wrote:
That may not always work, as you can superclass dialogs.

I got an idea about using one of the dlg based functions on a non-dlg window and eventually found this system error:

ERROR_WINDOW_NOT_DIALOG - The window is not a valid dialog window

The problem is, the only dialog function I can find that returns the value is EndDialog.

if (!EndDialog(hWnd, 0))
{
if (GetLastError() == ERROR_WINDOW_NOT_DIALOG)
// it's not a dialog!
}
else
// it's a dialog! Hey, where'd it go?

Pssst. You see that little light on your monitor? That's actually a government installed spy camera. Smile and wave to big brother!

Re: Win32: IsDialog(HWND)?

Jörgen Sigvardsson12-Jun-05 5:23

Jörgen Sigvardsson

12-Jun-05 5:23

EndDialog is not the ideal function in most cases. Wink | ;)

How about MapDialogRect(), or GetDlgItem()?

--
An eye for an eye will only make the world blind.

Re: Win32: IsDialog(HWND)?

Jack Puppy12-Jun-05 14:45

Jack Puppy

12-Jun-05 14:45

Tried GetDlgItem before, didn't work. MapDialogRect does work though.

Pssst. You see that little light on your monitor? That's actually a government installed spy camera. Smile and wave to big brother!

function pointer on classfunctions

tbrake11-Jun-05 22:45

tbrake

11-Jun-05 22:45

H@llo

I have a class with some memberfunctions and like to refer to these by unsing functionpointers.
all my tries ends up in errors
some sample here:

<br />
// myCom.h<br />
class myCom<br />
{<br />
  public:<br />
  int send(int,char*);<br />
  int read(int,unsigned int,BYTE*);<br />
};<br />

<br />
// action.h<br />
class myCom;<br />
typedef int (*cdout)(int  ,char* );<br />
typedef int (*cdread)(int ,unsigned int ,BYTE* );<br />
class action<br />
{<br />
  myCom* mCom;<br />
  ...<br />
};<br />

<br />
// action.cpp<br />
...<br />
  mCom = new myCom;<br />
...<br />
  cdout test = mCom->send; // error C2440: 'initializing' : cannot convert from '' to 'int (__cdecl *)(int,char *)'<br />
or<br />
  cdout test;<br />
  test = mCom->send;      // error C2440: '=' : cannot convert from 'int (__thiscall CINTERFACE::*)(int,char *)' to 'int (__cdecl *)(int,char *)'<br />
...<br />

Anyone any idea??

THX

Re: function pointer on classfunctions

toxcct11-Jun-05 22:57

toxcct

11-Jun-05 22:57

you have
typedef int (*cdout)(int ,char* ); and
int send(int,char*);

but send is a member function... its synopsis is not what you wrote. it gets an implicit parameter (this). send() actually has 3 parameters.

if you want to use it, you must declare it as a static function.
but if it uses data members of its class, it won't see them anymore.
so you'll have to pass a new parameter explicitely to your send() function to allow it accessing the members. You'll also have to change the cdout declaration...

cheers,

TOXCCT >>> GEII power
[toxcct][VisualCalc]

Re: function pointer on classfunctions

tbrake11-Jun-05 23:18

tbrake

11-Jun-05 23:18

Hallo

OK - got it so far. Smile | :)

But at least i like to send this functionpointer to a created dll.
So ifsend() is static i have to change to much code.
Changeing the typedef restricts the needed parsing possibility
for my dll.
D'Oh! | :doh:

I'm sorry, but i'm not very good in c programming. Is there any other fast possibility to call a dll function that communicating with class member functions?
Confused | :confused:

THX

Re: function pointer on classfunctions

toxcct11-Jun-05 23:24

toxcct

11-Jun-05 23:24

just put send not a member function... (say it is global... or at least, from within a namespace of your own)

TOXCCT >>> GEII power
[toxcct][VisualCalc]

Re: function pointer on classfunctions

Behzad Ebrahimi12-Jun-05 4:09

Behzad Ebrahimi

12-Jun-05 4:09

See Class function callback[^]

I am stuck please help me

Aqueel11-Jun-05 20:57

Aqueel

11-Jun-05 20:57

Hello brothers...
I tried my best but could not get solution to my problem. Please help me.
I can not understand why this error message is comming. I have changed my code but error is still there.

My code is as follows.

void CMyThreadDlg::OnOK()
{
if (m_check) // if check box is checked
{
AfxBeginThread(ThreadProc,NULL,THREAD_PRIORITY_NORMAL,0,0,NULL);
MessageBox("Thread Started");
}

CDialog::OnOK();
}

UINT ThreadProc( LPVOID Param )
{
ofstream fout;
fout.open("thread.txt");

for(int i=0;i<=100;i++)
{
fout <<i <<' ';
}
fout.close();

return 0;
}

Error message is,
<b>AfxBeginThread' : ambiguous call to overloaded function</b>

We Believe in Excellence

Re: I am stuck please help me

toxcct11-Jun-05 23:00

toxcct

11-Jun-05 23:00

maybe ThreadProc is an identifier already existing...
you could either change its name, or use the :: scope operator...

(and please explain better you problems next time...)

TOXCCT >>> GEII power
[toxcct][VisualCalc]

Re: I am stuck please help me

eli1502197911-Jun-05 23:35

eli15021979

11-Jun-05 23:35

Hi,
I think you ar passing to many parametrs to AfxBginThread() (I don't have MSDN on this computer...).
Anyway try this :

void CMyThreadDlg::OnOK() 
{
   if (m_check) // if check box is checked
   {
      AfxBeginThread(ThreadProc,NULL);
      MessageBox("Thread Started");
   }

   CDialog::OnOK();
}

[EDIT]
I've checked and you are passing the right parameters,so you have 2 more options:

1. Declare your thread on top of your file:

UINT ThreadProc(LPVOID lpvoid);

and then use it.

2. You already have a function calld ThreadProc.
Try a different name to your thread.

Regards,
Eli

Re: I am stuck please help me

toxcct12-Jun-05 0:11

toxcct

12-Jun-05 0:11

eli15021979 wrote:
I don't have MSDN on this computer...

www.msdn.microsoft.com[^]...

TOXCCT >>> GEII power
[toxcct][VisualCalc]

Re: I am stuck please help me

eli1502197913-Jun-05 20:09

eli15021979

13-Jun-05 20:09

thanx,I forgot it.... D'Oh! | :doh:

Eli

Re: I am stuck please help me

S. Senthil Kumar12-Jun-05 4:52

S. Senthil Kumar

12-Jun-05 4:52

Did you try declaring ThreadProc before using it. Something like

UINT ThreadProc( LPVOID Param );
void CMyThreadDlg::OnOK()
{
...

IIRC, the compiler creates a function that takes and returns void if you don't define one before using it. Or is it only a C language feature?

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: I am stuck please help me

toxcct12-Jun-05 20:30

toxcct

12-Jun-05 20:30

S. Senthil Kumar wrote:
Or is it only a C language feature?

yep. C only...

TOXCCT >>> GEII power
[toxcct][VisualCalc]

BSTR

pardis11-Jun-05 19:52

pardis

11-Jun-05 19:52

hi
is it possible to send a BSTR to a method expecting a _bstr_t?

Re: BSTR

Gary R. Wheeler12-Jun-05 2:00

Gary R. Wheeler

12-Jun-05 2:00

void function(_bstr_t string);
BSTR BSTR_string;
function(_bstr_t(BSTR_string,true));

The bool argument to the _bstr_t constructor specifies whether you want to copy the string or simply attach it to the _bstr_t object you're creating.

Software Zen: delete this;

Moving Non-Title Dialog

Tran Duy Hung11-Jun-05 17:55

Tran Duy Hung

11-Jun-05 17:55

The task is to create non-title dialog which allows user to move it arround the desktop.
As we all knew, user can move the normal dialog by click left button and drag the mouse while it is in the Title area. My dialog have no title, how I can perform the task.

I have tried to handle events WM_LBUTTONDOWN and WM_MOUSEMOVE in the WindowProc procedure of the dialog.
I can move the dialog, but the problem is:
The dialog can't move smoothly. It is flicking
Does any one help me to handle the task better?

Thanks very much

TDH

Re: Moving Non-Title Dialog

Ravi Bhavnani11-Jun-05 19:42

Ravi Bhavnani

11-Jun-05 19:42

Add a handler for WM_NCHITTEST and just return HT_CAPTION.

UINT CMyDlg::OnNcHitTest(CPoint point) 
{
  return (HTCAPTION);
}

/ravi

My new year's resolution: 2048 x 1536
Home | Articles | Freeware | Music
ravib@ravib.com

Re: Moving Non-Title Dialog

Gary R. Wheeler12-Jun-05 2:01

Gary R. Wheeler

12-Jun-05 2:01

I'll have to remember that one.

Software Zen: delete this;

How to update/refresh/resize the systray after replace the windows clock with static

ELY M.11-Jun-05 17:47

ELY M.

11-Jun-05 17:47

I been working on this clock replacement program because I never find
any open source ones.

I been having problem with the code and cant find a way to auto
update/refresh my systray to fit my clock replacement.

I already looked all over google and news groups.

Take a look at those pics

before I run the program
http://69.50.187.114/~area51/before.gif

after I run the program = notice I lost my AIM icon.... it overlapped
the AIM icon.
http://69.50.187.114/~area51/after.gif

my program is MFC based.

I decided to include my code for people to take a look at.

http://69.50.187.114/~area51/Start_Button_Clock_Changer.zip

Click on the "Change Clock" button on the dailog. you will see what I
mean.

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