Re: Message Loop - C / C++ / MFC Discussion Boards

Re: Message Loop

Naveen16-Aug-07 21:05

Naveen

16-Aug-07 21:05

baerten wrote:
DOS-Application

if you mean is a console application, yes its possible...

nave

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Re: Message Loop

baerten16-Aug-07 21:13

baerten

16-Aug-07 21:13

Yes, it's a console application

Need i to launch a thread where i instantiate a class which has a message loop?
And all messages where handled into this class...

Thanks for your help Smile | :)

Re: Message Loop

Naveen16-Aug-07 21:17

Naveen

16-Aug-07 21:17

No need of seperate thread. All you have to do is to create a window and below that you can write the message loop.

nave

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Re: Message Loop

Stephen Hewitt16-Aug-07 22:26

Stephen Hewitt

16-Aug-07 22:26

There is no need to crate a window to have a message loop. Just put one in and it will work fine.

Steve

Re: Message Loop

baerten16-Aug-07 22:42

baerten

16-Aug-07 22:42

at the main function of the console application i start a new thread via AfxBeginThread
In the function, which will be started from AfxBeginThread i used this code:

MSG msg;
while(1) {
  if(::PeekMessage(&msg,hWndofTheConsole,0,0,PM_REMOVE)) {
    printf("I GOT A MESSAGE");
    if(msg.message == WM_USER+55) ..............
  }
}

But i receive no message, even not he OnKeyDown Messages

An MFC Program opens this Console Application via CreateProcess
I can send keystrokes from out the MFC-Applic to the Console and there, the letters will be entered.
So the WM_KEYDOWN Messages will arrive correcly the console

I tested also the hWndofTheConsole, i performed a ShowWindow(hWndofTheConsole,SW_SHOW/SW_HIDE)
and the console appears and disappears, so the HWND is correct.

But, why i can't catch the messages Sigh | :sigh:

Thanks for your help you two Big Grin | :-D

Re: Message Loop

David Crow17-Aug-07 4:06

David Crow

17-Aug-07 4:06

Are you wanting the console application to receive input from the GUI application? If so, see here and here.

"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: Message Loop

Naveen16-Aug-07 22:47

Naveen

16-Aug-07 22:47

Stephen Hewitt wrote:
There is no need to crate a window to have a message loop. Just put one in and it will work fine.

I doubt this is because of the console window in the main thread. How ever I dont think a simmple message loop will work in a new thread, unless window is created.

nave

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Re: Message Loop

Stephen Hewitt19-Aug-07 14:46

Stephen Hewitt

19-Aug-07 14:46

You don't need a window to have a message loop. The existence of the PostThreadMessage[^] function should hint at this: it sends a message but takes no window handle. The simple test application which follows proves the point:

// MessageLoopNoWindow.cpp : Defines the entry point for the console application.
//
 
#include "stdafx.h"
#include <windows.h>
#include <iostream>
#include <conio.h>
 
int main(int argc, char* argv[])
{
	using namespace std;
 
	DWORD idUs = GetCurrentThreadId();
	PostThreadMessage(idUs, WM_APP, 0, 0);
 
	MSG msg;
	while (GetMessage(&msg, NULL, 0, 0))
	{
		if (msg.message == WM_APP)
		{
			cout << "Got message but have no window!" << endl;
			PostQuitMessage(0);
		}
	}
 
	cout << "Press any key...";
	_getch();
 
	return 0;
}

In short: messages are sent to threads or windows (and windows are always ownded by a particulat thread) ; message pumps process messages for a particular thread.

Steve

No effect

baerten16-Aug-07 23:12

baerten

16-Aug-07 23:12

I set the loop with ::PeekMessage into the main_function, but no effect Sigh | :sigh:

How do you mean "create a new window to add a message loop" to create a simple CDialog-derived window ?
In this case the dialog has a new Handle and the MFC Application sends the messages to the process/main-thread, so the messages don't travel to the dialog, or?

All this work to transmit two int's to another process Unsure | :~

I think i will write the int-values as text and the Console reads the values, that's very stupid,
but works Dead | X|

Re: No effect

Naveen16-Aug-07 23:30

Naveen

16-Aug-07 23:30

I think its hard to get the messages of a console window. I am not sure but i think you can try hooking( SetWindowsHookEx() ).

nave

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Re: Message Loop

Gary R. Wheeler18-Aug-07 3:44

Gary R. Wheeler

18-Aug-07 3:44

Try here[^]; this section of Code Project deals with inter-process communication. There are easier ways to pass data between processes than the Windows message mechanism, especially when both of the apps aren't windowed applications.

Software Zen: delete this;

Fold With Us![^]

Thanks at you all!

baerten19-Aug-07 21:04

baerten

19-Aug-07 21:04

<blank>

Convert CString to const unsigned short *

__yash__16-Aug-07 20:38

__yash__

16-Aug-07 20:38

convert cstring to const unsigned short *
How can i achieve this??

Re: Convert CString to const unsigned short *

KarstenK16-Aug-07 20:48

KarstenK

16-Aug-07 20:48

This is a really bad idea. A CString is an object representing a memory area in the PC. You can interpret to a pointer BUT it should be temporary. => (LPCSTR).

(const unsigned short *)(LPCSTR)

But there is no unsigned short D'Oh! | :doh:

!!!!

RTFM

Greetings from Germany

Re: Convert CString to const unsigned short *

__yash__16-Aug-07 20:55

__yash__

16-Aug-07 20:55

VARIANT v;

First case:
v.bstrVal = SysAllocString(sz);
//where sz is a OLECHAR FAR*

Second case:
v.bstrVal =sz.AllocSysString();
//where sz is a CString

Second case solved my problem

Re: Convert CString to const unsigned short *

KarstenK16-Aug-07 21:22

KarstenK

16-Aug-07 21:22

The right decription is often half of the solution of the problem!!! Cool | :cool:

For these String conversion are some API function and macros available. Its better to use them.
I dont need them often so I dont remember gut I guess like OLE2CHAR( ) Confused | :confused:

Greetings from Germany

Re: Convert CString to const unsigned short *

Naveen16-Aug-07 21:25

Naveen

16-Aug-07 21:25

yashveer wrote:
v.bstrVal =sz.AllocSysString();

dont forget to free it using the SysFreeString().

nave

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Re: Convert CString to const unsigned short *

__yash__16-Aug-07 22:08

__yash__

16-Aug-07 22:08

ya i m actually using
SysFreeString()
I wouldnt have known about all this. I was searching for a way to convert text to csv.... i found something on msdn online Wink | ;-)

http://support.microsoft.com/kb/179706/
Instead of fixed string given in the code:
FillSafeArray(L"John", 0, 0, &saRet);
I wanted to use the following:
FillSafeArray(str, 0, 0, &saRet);
where str is CString

and hence....all this

Re: Convert CString to const unsigned short *

Naveen16-Aug-07 20:52

Naveen

16-Aug-07 20:52

Use the MultiByteToWideChar() function.

Other option is to define the _UNICODE in the project setting preprocessor definitions, so that the CString will be keeping wide characters internally and hence no conversion is requirent

nave

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Re: Convert CString to const unsigned short *

Suneet.0316-Aug-07 22:47

Suneet.03

16-Aug-07 22:47

You can use MultiByteToWideChar may be somethng like this

CString str;
wchar_t* wch

MultiByteToWideChar(CP_ACP,0,str,strlen(str),wch,strlen(str),NULL,NULL)

Don't forget to allocate memory to this wchar variable

then typecast this wchar to unsigned short*

FillSafeArray((unsigned short*)wch ,....)

I think this will help u out !!!

Re: Convert CString to const unsigned short *

Suneet.0317-Aug-07 0:04

Suneet.03

17-Aug-07 0:04

typecast it to const unsigned short* .....

FillSafeArray((const unsigned short*).....

UTF-8 and MultiByte

sandeepkavade16-Aug-07 20:11

sandeepkavade

16-Aug-07 20:11

hi all
can anybody tell me is whats the difference between UTF-8 and multibyte.
and from where i can find more information on the same?
Thanx in advance.

Re: UTF-8 and MultiByte

Hans Dietrich17-Aug-07 1:05

Hans Dietrich

17-Aug-07 1:05

Google for "UTF-8 multibyte" and you will get many hits. Try Wikipedia first.

Best wishes,
Hans

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Re: UTF-8 and MultiByte

Nemanja Trifunovic17-Aug-07 1:40

Nemanja Trifunovic

17-Aug-07 1:40

UTF-8 is a Unicode encoding scheme.

Multibyte is a common name for a number of legacy encodings that typically store strings in char arrays (in C) as opposed to wchar_t arrays.

Programming Blog
utf8-cpp

Re: UTF-8 and MultiByte

jhwurmbach17-Aug-07 3:02

jhwurmbach

17-Aug-07 3:02

Nemanja Trifunovic wrote:
Multibyte is a common name for a number of legacy encodings that typically store strings in char arrays

Thus in the sense of your definition UTF-8 is a multibyte-format.
UTF-16 (not that someone in his right mind would use that) isn't.

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