C / C++ / MFC Discussion Boards

Re: AfxBeginThread() with a function in the main class

Johpoke3-Aug-07 6:52

3-Aug-07 6:52

Ah yes now it compiles, thanks.

But when i add a function to it (one that is connected to CThreadDemoDlg) i get the cant call a nonstatic member function..

error C2352: 'CThreadDemoDlg::SomeFunction' : illegal call of non-static member function
see declaration of 'SomeFunction'

So how should i go about calling the function?

thanks again!

//Johannes

Re: AfxBeginThread() with a function in the main class

David Crow3-Aug-07 6:54

David Crow

3-Aug-07 6:54

Johpoke wrote:
So how should i go about calling the function?

Can you at least bother to show the code that is producing this error? Roll eyes | :rolleyes:

"A good athlete is the result of a good and worthy opponent." - David Crow

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

Re: AfxBeginThread() with a function in the main class

Johpoke3-Aug-07 6:59

Johpoke

3-Aug-07 6:59

Doh,

UINT __cdecl CThreadDemoDlg::MyThreadProc(LPVOID pParam)<br />
{<br />
   CThreadDemoDlg *pMyDlg = (CThreadDemoDlg *)pParam;<br />
<br />
   MyFunction();<br />
<br />
   return 1;<br />
}

It looks exactly like that, except the names are different

//Johannes

Re: AfxBeginThread() with a function in the main class

David Crow3-Aug-07 7:05

David Crow

3-Aug-07 7:05

Hint: Ever wonder what pMyDlg is being used for?

"A good athlete is the result of a good and worthy opponent." - David Crow

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

Re: AfxBeginThread() with a function in the main class [Solved]

Johpoke3-Aug-07 7:12

Johpoke

3-Aug-07 7:12

I was thinking i must use it to gain access to the rest of the functions so i like tried :: on it but that didnt work. Now i tried -> on it and all my functions come up Big Grin | :-D

Thanks alot for the help. The only downside with this is im probably gonna have to go through loads of old programs and get rid of their ugly methods and add this. But i guess its worth it Big Grin | :-D

Thanks again Smile | :)

//Johannes

Re: AfxBeginThread() with a function in the main class

Ahmad Al-Maraghi4-Aug-07 1:50

Ahmad Al-Maraghi

4-Aug-07 1:50

u don't understand the problem Frown | :(

Re: AfxBeginThread() with a function in the main class

led mike3-Aug-07 7:08

led mike

3-Aug-07 7:08

Johpoke wrote:
but its giving me an error message i really dont understand..

You don't understand a syntax error message but you are working with multi threading *sigh* different day same old garbage

Re: AfxBeginThread() with a function in the main class

Mark Salsbery3-Aug-07 7:32

Mark Salsbery

3-Aug-07 7:32

led mike wrote:
*sigh* different day same old garbage

This[^] should cheer you up.

Beer | [beer]

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

Re: AfxBeginThread() with a function in the main class

led mike3-Aug-07 7:43

led mike

3-Aug-07 7:43

Good Grief Sigh | :sigh:

Happy Friday Beer | [beer]

Re: AfxBeginThread() with a function in the main class

Johpoke3-Aug-07 7:59

Johpoke

3-Aug-07 7:59

lol, that dancing dude is funny/weird.

My program now works perfectly, thank you all for you help.

How does one make that dude anyway? i cant find him...

//Johannes

Re: AfxBeginThread() with a function in the main class

led mike3-Aug-07 8:09

led mike

3-Aug-07 8:09

Johpoke wrote:
My program now works perfectly

If it works, do it.

If it works, do it it works

  seems to work      probably
     ^                  ^
If it   works, do it it    works

  seems to work      probably
     ^                  ^
If it   works, do it it    works
	
(and might work again)

Cogito ergo sum

(although, admittedly, that is an assumption)

Re: AfxBeginThread() with a function in the main class

Mark Salsbery3-Aug-07 8:14

Mark Salsbery

3-Aug-07 8:14

Johpoke wrote:
How does one make that dude anyway? i cant find him...

It's right next to the Beer | [beer]

one.

With a little ingenuity, you'll find it Smile | :)

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

Re: AfxBeginThread() with a function in the main class

Johpoke3-Aug-07 8:27

Johpoke

3-Aug-07 8:27

Maybe its like a gold-member only emotion. or maybe it doesnt like me...

Ah well doesnt matter im happy anyway Smile | :)

//Johannes

Re: AfxBeginThread() with a function in the main class

Mark Salsbery3-Aug-07 8:34

Mark Salsbery

3-Aug-07 8:34

Johpoke wrote:
Maybe its like a gold-member only emotion.

Nope. I was so proud when I found it all by myself, since I know nothing about web programming Smile | :)

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

Re: AfxBeginThread() with a function in the main class

Johpoke3-Aug-07 8:40

Johpoke

3-Aug-07 8:40

//Johannes

Re: AfxBeginThread() with a function in the main class

Mark Salsbery3-Aug-07 8:57

Mark Salsbery

3-Aug-07 8:57

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

Re: AfxBeginThread() with a function in the main class

Mark Salsbery3-Aug-07 8:13

Mark Salsbery

3-Aug-07 8:13

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

PostThreadMessages lost in DLL

PaulCammy3-Aug-07 5:54

PaulCammy

3-Aug-07 5:54

I have a DLL that has a class derived from CWinApp.

I have another class in the DLL that needs to trigger an asynchronous process within that same DLL. Since the DLL has no window I use PostThreadMessage to trigger the process as follows:

<code>void CMyClass::TriggerAsyncProc() const
{
AfxGetApp()->PostThreadMessage(WMU_MYMSG, 0, 0L) ;
}</code>

In my class derived from CWinApp, I have tried two different methods to trap WMU_MYMSG. The first was to override PreTranslateMessage, and the second was to try to use the CWinApp message map (via ON_THREAD_MESSAGE).

The DLL is being used by a dialog application, and the TriggerAsyncProc is definately sending the message because PostThreadMessage(WMU_MYMSG, 0, 0L) returns non-zero.

The only thing I can think of is that my message is going through the message map of the dialog application instead of my class derived from CWinApp in the DLL.

Please can someone tell me why I'm losing the message, and suggest either how I correct this or an alternative method?

Thanks.
Confused | :confused:

Re: PostThreadMessages lost in DLL

Mark Salsbery3-Aug-07 6:07

Mark Salsbery

3-Aug-07 6:07

This doesn't sound like it would work.

A DLL that has a CWinApp object is supported, but that CWinApp object doesn't have its own message pump.
I wouldn't expect any messages to be processed in the DLL's CWinApp object unless you've tweaked something
to do so.

Here's what the docs state about this situation:

"Note that the CWinApp::Run mechanism does not apply to a DLL, because the application owns the main message pump.
If your DLL brings up modeless dialogs or has a main frame window of its own, your application's main message pump must
call a DLL-exported routine that calls CWinApp::PreTranslateMessage."

Mark

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

Re: PostThreadMessages lost in DLL

PaulCammy4-Aug-07 1:52

PaulCammy

4-Aug-07 1:52

Thanks for that. It's a pity that the DLL Wizard created a CWinApp derived class that includes Message Map macro declarations.

There is a possiblity that the main applications using my DLL will not have a main frame window - they may also be ATL applications. Please could you advise what I could do in these cases?

Thanks

Re: PostThreadMessages lost in DLL

Mark Salsbery4-Aug-07 6:42

Mark Salsbery

4-Aug-07 6:42

I would suggest reading this: Kinds of DLLs[^]

It outlines the methods and requirements of different MFC DLL scenarios.

Maybe it'll help choose an appropriate method for your needs.

Mark

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

Re: PostThreadMessages lost in DLL

PaulCammy5-Aug-07 22:23

PaulCammy

5-Aug-07 22:23

Thanks again.

Not a lot of help there about this particular situation, but some useful info. none the less.

Cheers.

Re: PostThreadMessages lost in DLL

Blake Miller6-Aug-07 5:06

Blake Miller

6-Aug-07 5:06

What I have done within a DLL 'init' function that the client must call - AFTER the client has already loaded all its dll and such, is to create a new thread. All the work within the DLL I wrote was done from within this thread internal to the DLL.
At the top of this thread place a PeekMessage call, so the thread will get a message queue. Then you can process 'posted thread messages' fromt this thread and it has its own independent message pump.

Just because an app stared as a dialog app, or some other type of app, does not mean it can't have a DLL containing its own thread and its own message queue.

Re: PostThreadMessages lost in DLL

Mark Salsbery6-Aug-07 5:06

Mark Salsbery

6-Aug-07 5:06

Yeah. The main point is...

when using MFC in a "regular DLL" (that can be used by an MFC or non-MFC app) then
you have to provide the message pump.

There's also subtle differences in MFC initialization, but if you use the wizards, that code
is created for you.

Mark

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

differentiating between literal strings and char pointers [modified]

dburns3-Aug-07 4:48

dburns

3-Aug-07 4:48

Hi,

Suppose I have a method foo that takes a const char* param. I have a case where I can be more efficient if the caller passes in a "quoted literal string" vs the contents of some arbitrary buffer (because I don't have to copy the string data in the first case).

((UPDATE: To be clear, the class with method foo needs to store the supplied string away for later access, internally. For a literal string, it's safe to store the pointer only. For a non-literal, it's necessary to copy the data in case the original caller's buffer goes away or is modified before the class instance goes away.))

Pretty sure the answer is "you can't", but I thought I'd check if anyone can think of a way to overload the method foo such that one version is invoked for

char buff[100];<br />
...<br />
const char* p_buff = buff;<br />
myclass.foo(p_buff)

and the second version is invoked for

myclass.foo("literal string")

?

I can't change the name of foo or have the caller specify explicitly which one they want. This sample is just an illustration.

Thanks!
DB

-- modified at 12:11 Friday 3rd August, 2007

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