C / C++ / MFC

_beginthread, can we create a thread in a class? [modified]

11-Nov-07 6:12

Maybe you didn't read the post...

It does everything I want it to do...that changes several times a day.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: User Interface

DevMentor.org10-Nov-07 15:17

DevMentor.org

10-Nov-07 15:17

She sure is Sexxy Laugh | :laugh:

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Gofur Halmurat9-Nov-07 11:53

Gofur Halmurat

9-Nov-07 11:53

Hello,
I have a class which i created, it calculates some mathematical functions, Can i use or create "_beginthread" in the class?

i tried to do it, but i got this error:
error C2664: '_beginthread' : cannot convert parameter 1 from 'void (void *)' to 'void (__cdecl *)(void *)'

class CMaClasse<br />
{<br />
public:<br />
 void FoncAppnt(void* args);<br />
 void FoncApp(void* arg);<br />
};<br />
 <br />
void CMaClasse::FoncAppnt(void* args)<br />
{<br />
_beginthread(FoncApp,0,(void*)a); <br />
}<br />
 <br />
 <br />
void CMaClasse::FoncApp(void* arg)<br />
{<br />
 //...<br />
}

-- modified at 18:18 Friday 9th November, 2007

Re: _beginthread, can we create a thread in a class?

Mark Salsbery9-Nov-07 12:32

Re: _beginthread, can we create a thread in a class?

9-Nov-07 12:32

Gofur Halmurat wrote:
Can i use or create "_beginthread" in the class?

Sure. But, if your thread proc is a class method, that method needs to be static...

class CMaClasse<br />
{<br />
public:<br />
 void FoncAppnt(void* args);<br />
static void FoncApp(void* arg);<br />
};<br />
 <br />
void CMaClasse::FoncAppnt(void* args)<br />
{<br />
_beginthread(&

CMaClasse::

FoncApp,0,(void*)a); <br />
}<br />
 <br />
 <br />
void CMaClasse::FoncApp(void* arg)<br />
{<br />
 //...<br />
}

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Gofur Halmurat9-Nov-07 12:39

Gofur Halmurat

9-Nov-07 12:39

Can I use public variable in static function?
because i have some public variables in the class

Re: _beginthread, can we create a thread in a class?

Mark Salsbery9-Nov-07 12:49

Re: _beginthread, can we create a thread in a class?

9-Nov-07 12:49

A static method can only access static class members.

To get around this, typically a pointer to an object of the class is passed
to the thread proc. Then the thread proc can use that pointer to access
non static members of the class.

Here's an example (my changes are in red)...

class CMaClasse
{
   <font color="Red">void *pThreadArgs;</font>
public:
   void FoncAppnt(void* args);
   static void FoncApp(void* arg);
};

void CMaClasse::FoncAppnt(void* args)
{
   <font color="Red">pThreadArgs = args;</font>

   _beginthread(&CMaClasse::FoncApp,0,<font color="Red">this</font>);
}


void CMaClasse::FoncApp(void* arg)
{
<font color="Red">   // The passed param is a CMacClasse pointer
   CMaClasse *pThis = (CMaClasse *)arg;

   // example of accessing a class member
   pThis->pThreadArgs->...</font>

   //...
}

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Gofur Halmurat9-Nov-07 13:15

Gofur Halmurat

9-Nov-07 13:15

thanks Mark,
It helped me alot!!!

Re: _beginthread, can we create a thread in a class?

George L. Jackson9-Nov-07 13:25

George L. Jackson

9-Nov-07 13:25

Here's a tutorial that may be helpful. I tried to post this earlier but got some goofy error.

http://www.computersciencelab.com/MultithreadingTut1.htm[^]

"We make a living by what we get, we make a life by what we give." --Winston Churchill

Re: _beginthread, can we create a thread in a class?

dtr19-Nov-07 20:37

dtr1

9-Nov-07 20:37

Just to explain this behavior see: http://www.parashift.com/c++-faq-lite/pointers-to-members.html.
Briefly, the type of pointer-to-member-function is different from pointer-to-function .There is not cast (new in VC++2005).

Re: _beginthread, can we create a thread in a class?

George L. Jackson10-Nov-07 0:05

George L. Jackson

10-Nov-07 0:05

george.dumitru wrote:
There is not cast (new in VC++2005).

I never heard of "not cast"! Confused | :confused:

"We make a living by what we get, we make a life by what we give." --Winston Churchill

Re: _beginthread, can we create a thread in a class?

dtr110-Nov-07 0:17

dtr1

10-Nov-07 0:17

There is no cast to non-member function pointer.

RC2135

Dr. Emmett Brown9-Nov-07 11:51

Dr. Emmett Brown

9-Nov-07 11:51

Hi All,
I'm sure that someone has had this problem before. I only wanted to reorganize the constants a little bit when I decided to compile again and boom! ... the famous RC2135 while compiling resources. I installed SP1 but it's still there. I can't compile my project anymore.

I really appreciate any help.
Thanks.

rotter

check for decimal in numerical string

kani989-Nov-07 11:40

kani98

9-Nov-07 11:40

I have an input box that a user can enter in 4 characters like 1.34. I need to check if there is a decimal in the input string and truncate everything after the tenth place. Is there a C/C++ function that I can use for this? Thanks

Re: check for decimal in numerical string [modified]

chandu0049-Nov-07 20:44

chandu004

9-Nov-07 20:44

will CString :: Find help you?

dtr19-Nov-07 21:13

dtr1

9-Nov-07 21:13

Using "Add memmer variable wizard", add a variable (Category=value) and set ‘Max chars’ to n.
Or, DDV_MaxChars(pDX, yourVar, 10);

-- modified at 3:50 Saturday 10th November, 2007

Mark Salsbery10-Nov-07 6:01

10-Nov-07 6:01

george.dumitru wrote:
sing "Add memmer variable wizard", add a variable (Category=value) and set ‘Max chars’ to n.

How does that find the "decimal in the input string and truncate everything after the tenth place"???

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

David Crow10-Nov-07 15:47

David Crow

10-Nov-07 15:47

kani98 wrote:
I need to check if there is a decimal in the input string...Is there a C/C++ function that I can use for this?

Check out strchr(), or string::find(), or CString::Find().

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

CTreeCtrl not showing tree

kani9813-Nov-07 6:29

kani98

13-Nov-07 6:29

Is there a C/C++ funciton that will remove a character from a string? I want to remove the decimal from the input string. If someone enter 1.23, I want to use only 1.2, remove the decimal making it 12.

act_x9-Nov-07 10:20

act_x

9-Nov-07 10:20

I am trying to use the MS sample in my code and and cannot get it to add an other nodes other than the first node .

<br />
// Gain a pointer to our tree control<br />
<br />
CTreeCtrl* pCtrl = (CTreeCtrl*) GetDlgItem(IDC_TREE1);<br />
ASSERT(pCtrl != NULL);<br />
<br />
// Insert a root item using the structure. We must<br />
// initialize a TVINSERTSTRUCT structure and pass its<br />
// address to the call. <br />
<br />
TVINSERTSTRUCT tvInsert;<br />
tvInsert.hParent = NULL;<br />
tvInsert.hInsertAfter = NULL;<br />
tvInsert.item.mask = TVIF_TEXT;<br />
tvInsert.item.pszText = _T("United States");<br />
<br />
HTREEITEM hCountry = pCtrl->InsertItem(&tvInsert);<br />
<br />
// Insert subitems of that root. Pennsylvania is<br />
// a state in the United States, so its item will be a child<br />
// of the United States item. We won't set any image or states,<br />
// so we supply only the TVIF_TEXT mask flag. This<br />
// override provides nearly complete control over the<br />
// insertion operation without the tedium of initializing<br />
// a structure. If you're going to add lots of items<br />
// to a tree, you might prefer the structure override<br />
// as it affords you a performance win by allowing you<br />
// to initialize some fields of the structure only once,<br />
// outside of your insertion loop.<br />
<br />
HTREEITEM hPA = pCtrl->InsertItem(TVIF_TEXT,<br />
   _T("Pennsylvania"), 0, 0, 0, 0, 0, hCountry, NULL);<br />
<br />
// Insert the "Washington" item and assure that it is<br />
// inserted after the "Pennsylvania" item. This override is <br />
// more appropriate for conveniently inserting items with <br />
// images.<br />
<br />
HTREEITEM hWA = pCtrl->InsertItem(_T("Washington"),<br />
   0, 0, hCountry, hPA);<br />
<br />
// We'll add some cities under each of the states.<br />
// The override used here is most appropriate<br />
// for inserting text-only items.<br />
<br />
pCtrl->InsertItem(_T("Pittsburgh"), hPA, TVI_SORT);<br />
pCtrl->InsertItem(_T("Harrisburg"), hPA, TVI_SORT);<br />
pCtrl->InsertItem(_T("Altoona"), hPA, TVI_SORT);<br />
<br />
pCtrl->InsertItem(_T("Seattle"), hWA, TVI_SORT);<br />
pCtrl->InsertItem(_T("Kalaloch"), hWA, TVI_SORT);<br />
pCtrl->InsertItem(_T("Yakima"), hWA, TVI_SORT);

Anything missing here ?

Mark Salsbery9-Nov-07 10:30

9-Nov-07 10:30

Are you getting good HTREEITEM values returned from the InsertItem() calls?

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

act_x9-Nov-07 10:37

act_x

9-Nov-07 10:37

yes

Engineering is the effort !

Mark Salsbery9-Nov-07 10:41

9-Nov-07 10:41

Your code worked for me.

Try double clicking on United States.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]