C / C++ / MFC

mohit`1211-Aug-10 5:11

mohit`12

11-Aug-10 5:11

When i call invalidate() it just refresh the mytabcontrol and it blinks but it doesnt actully redraw the graph with new values. this is like scientific calculator with function on top inside formview and graphs on tabview(dialog mode). so each time i switch tab or change values in calculator it has to redraw graph depending upon the new values in calculator. if anyone have got idea how to do this or any hint.
PLEASE...
<<<<post here="">>>

THANKzzzzz

tanu misra7-Aug-10 1:05

tanu misra

7-Aug-10 1:05

hi If u r making a calculator,
u cn tk help of Visual C++ Programming By Mr.Yashwant Kanetkar
Page no.434.there he has given sum hints on this topic..
Smile | :)

Hope U solve your Problem soon..
All the Best
tc..

Iain Clarke, Warrior Programmer

Iain Clarke, Warrior Programmer8-Aug-10 21:36

8-Aug-10 21:36

tanu misra wrote:
u cn tk

Is your kbd broken? You seem to be missing some vowels.

Iain.

I am one of "those foreigners coming over here and stealing our jobs". Yay me!

GetQueuedCompletionStatus blocks, though GetLastError which is called after AcceptEx returns ERROR_IO_PENDING [modified]

mohit`129-Aug-10 4:47

mohit`12

9-Aug-10 4:47

thank you all for reply. I solved the problem, Calling ON_WM_PAINT() in your TabControl Class will call OnPaint.
But when i switch tabs it suppose to Call OnPaint each time so it redraw the graph. I called INVALIDATE() but doesn't seem like working since TabControl is not mainwindow. INVALIDATE only refresh the main window not the tabcontrol Frown | :(

followait6-Aug-10 4:59

followait

6-Aug-10 4:59

But the client can connect.

some of the test codes

server

void post_io_request_of_accept(SOCKET so_listen, PerIoData * per_io_data)
{
	DWORD bytes_received;	
	BOOL ok = AcceptEx(so_listen,
		per_io_data->so_local,
		per_io_data->buf,
		0,
		sizeof(SOCKADDR_STORAGE)+16,
		sizeof(SOCKADDR_STORAGE)+16,
		&bytes_received,
		per_io_data);
	DWORD err = GetLastError();
	if (ok)
	{
		assert(false);
	}
	else if (err==ERROR_IO_PENDING)
	{
	}
	else
		assert(false);
}

DWORD WINAPI ServingThreadProc(LPVOID pParam)
{
	DWORD bytes_tranfered;
	ULONG_PTR completion_key;
	PerIoData * per_io_data;

	while (true)
	{
		BOOL ok = GetQueuedCompletionStatus(HANDLE(pParam),
			&bytes_tranfered,
			&completion_key,
			(OVERLAPPED**)&per_io_data,
			INFINITE);
		assert(ok);		
		handle_io_completion(per_io_data);
	}
	return 0;
}

client

int main()
{
	WSADATA wsa;
	int res = WSAStartup(MAKEWORD(2,2), &wsa);
	assert(res==0);

	SOCKADDR_IN addr_in;
	addr_in.sin_family = AF_INET;
	addr_in.sin_addr.s_addr = inet_addr("127.0.0.1");
	addr_in.sin_port = htons(5150);
	ZeroMemory(&addr_in.sin_zero, sizeof(addr_in.sin_zero));

	SOCKET s = WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, 0, 0);
	assert(s!=INVALID_SOCKET);
	int ok = connect(s, (sockaddr*)&addr_in, sizeof(addr_in));
	assert(ok==0);

	for (int i=0; i<10; ++i)
	{
		char buf[256];
		sprintf_s(buf, sizeof(buf), "message %d", i);
		WSABUF wsa_buf;
		wsa_buf.buf = buf;
		wsa_buf.len = strlen(buf);
		DWORD bytes_sent;
		int res = WSASend(s, &wsa_buf, 1, &bytes_sent, 0, NULL, NULL);
		assert(res==0 && bytes_sent==wsa_buf.len);
		printf_s("sent: %s\n", buf);
		Sleep(1000);
	}

	WSACleanup();

	return 0;
}

If use PostQueuedCompletionStatus, GetQueuedCompletionStatus will be unblocked.
What is the problem?
Thanks.

modified on Friday, August 6, 2010 11:38 AM

Re: GetQueuedCompletionStatus blocks, though GetLastError which is called after AcceptEx returns ERROR_IO_PENDING

Moak7-Aug-10 7:02

Moak

7-Aug-10 7:02

Perhaps you can use a IOCP networking class from CodeProject (or somewhere else) as a basis for your code? See if it helps:

Internet & Network - Client/Server Development.

Smile | :)

Chat in Europe Java | [Coffee]

Now with 24% more Twitter

Queue Mouse event till process completes.

Member 38346306-Aug-10 3:58

Member 3834630

6-Aug-10 3:58

Hello,

I have an MFC dialog based application which does come sequence of tasks one after other.
Each process takes few minutes to complete.
I popup a dialog with cancel button on it with status of current task.

If use selects cancel on the popup dialog. The process has to wait till the current task complete and then stop executing next task.

Can someone tell me how to wait on process till it complete and then execute the mouse event.

Thanks in advance.

Sauro Viti6-Aug-10 4:27

6-Aug-10 4:27

You can do something like this: when the user presses Cancel, set a flag about it, then disable the button and optionally setup a label on you progress dialog that advice "Cancel in progress...", finally at the end of each task check the flag and if it is set stop processing the remaining ones.

Richard MacCutchan6-Aug-10 4:45

Richard MacCutchan

6-Aug-10 4:45

The IProgressDialog[^] interface provides everything you need for such a situation.

It's time for a new signature.

Member 383463011-Aug-10 3:59

Member 3834630

11-Aug-10 3:59

Thanks for the suggestion..

Any pointers for IProgressDialog example, would be of great help. As i am getting errors during compilation.
Else have to follow the other method.

Thanks a lot for the help..

Regards..

Connecting multi-webcam to perform perspective reconstruction

Richard MacCutchan11-Aug-10 5:13

Richard MacCutchan

11-Aug-10 5:13

Member 3834630 wrote:
Any pointers for IProgressDialog example,

I gave you the link in my previous message; it's a fairly simple one to implement.

Member 3834630 wrote:
i am getting errors during compilation.

Well, unless you tell us what the errors are we cannot help much.

It's time for a new signature.

ponyta6-Aug-10 0:25

ponyta

6-Aug-10 0:25

Dear all

I am doing a project which my professor ask me to perform perspective reconstruction with 2 USB camera and C++.

May I know is it possible to get signal from the two USB camera by C++ at the same time?
Also, is it possible to perform real-time perspective reconstruction by C++?

Thank you

Re: Connecting multi-webcam to perform perspective reconstruction

Sauro Viti6-Aug-10 0:43

Re: Connecting multi-webcam to perform perspective reconstruction

6-Aug-10 0:43

Here your answers:

yes, it is possible: you have to use DirectShow to do it, instantiate two IGraphBuilder and connect each of them to a different device
you have to add an ISampleGrabber filter to each of the two IGraphBuilder: this will give you the ability to grab a frame from the two devices in your code and process them. Anyway, it depends on what you mean with real-time: the two devices are not synchronized each other, then the two frames are not referred to the same time (the maximum time unalignment between the two frames depends on the frame-rate of the two devices)

ponyta6-Aug-10 3:19

ponyta

6-Aug-10 3:19

I have no knowledge about DirectShow, so I may asking some stupid question, sorry.

Reply to your answer.
If I have two USB camera and connecting to my compuer, how can i get the signal and store into IGraphBuilder? What code should I write?

After I looked for some reference, someone is using the following code to get the signal:
IMoniker * pMonCam1 = NULL;
IMoniker * pMonCam2 = NULL;
pMonCam1=getDevices(0);
pMonCam2=getDevices(1);

Is these code can already get the signal?

Re: Connecting multi-webcam to perform perspective reconstruction

Sauro Viti6-Aug-10 3:51

6-Aug-10 3:51

Using the DirectShow is a bit more complicated! As a pre-requisite, you need to be able to deal with COM programming.
Look at these links to get an idea about what you should do:

Using DirectShow (Windows)[^]
Basic DirectShow Tasks (Windows)[^]
Video Capture (Windows)[^]
Selecting a Capture Device (Windows)[^]
PlayCap Sample (Windows)[^]: this is a sample from the Windows SDK that shows how to render the video stream of the first device found in the system
AmCap Sample (Windows)[^]: a more sofisticated sample about video capture

You can also have a look to the OpenCV library[^]: it's a huge library initially developed at Intel and later released to the open-source. It gives a lot of functionalities about image processing (OpenCV stands for Open Computer Vision), then you could find in it useful algorithms both to capture the video stream from various devices and to process the images aquired...

Fill array

AbhiHcl6-Aug-10 0:02

6-Aug-10 0:02

Hi I have two char array which I need to fill by parsing the string.
char * str = "1,aaa\r\n2,bbb\r\n3,ccc\r\n4,ddd\r\n"
now the the first value(1,2,3,4 in this case ) has to fill in first array and second value(aaa,bbb,ccc,ddd in this case) has to fill in second array.

Can anybody please help me how to do this.
please provide me a sample code if possible.

Thanks

bleedingfingers6-Aug-10 0:12

bleedingfingers

6-Aug-10 0:12

Tokenize thrice. Once with "\r\n" as the delimiter to count the number of array elements. Allocate two new arrays with that size. Then repeat the previous tokenizing to split one line and then tokenize the got line with "," to get the number and the text. Keep an index counter and fill both the arrays simultaneously.

You must be able to code what I said.

...byte till it megahertz...

AbhiHcl6-Aug-10 0:23

6-Aug-10 0:23

Thanx for ur reply, Can u please gv me some ssample code as I m new in c++.

bleedingfingers6-Aug-10 0:25

bleedingfingers

6-Aug-10 0:25

NO.

...byte till it megahertz...

bleedingfingers6-Aug-10 1:44

bleedingfingers

6-Aug-10 1:44

Well, because you have indeed attempted something, I'll help with a very very basic implementation.

void Job()
{
	char *data = strdup("1,aaa\r\n2,bbb\r\n3,ccc\r\n4,ddd\r\n");

	// count the dest array size
	char *p = data;
	int n = 0;
	while(*p)
	{
		if('\r' == *p)
		{
			n++;
			p++;
		}
		p++;
	}

	// create the dest arrays
	char **text = new char*[n];
	int *nums = new int[n];

	// start splitting
	int i = 0;
	char *tok = strtok(data, "\r\n");
	while(tok)
	{
		char *t = tok;
		while(*tok)
		{
			if(',' == *tok)
			{
				*tok = 0;
				nums[i] = atoi(t);
				t = tok+1;
			}
			tok++;
		}
		text[i] = strdup(t);
		i++;
		tok = strtok(NULL, "\r\n");
	}

	// clear all
	for(i = 0; i<n; i++)
		free(text[i]);
	delete [] text;
	delete [] nums;
	free(data);
}

It is not recommended to play around with too many pointers. Use std::string and std::vector in place of arrays. And use strtok_s(...) instead of strtok(...) to reduce those loops into simple function calls. I am using VC6 which doesn't have that and hence have written out those loops.

...byte till it megahertz...

_AnsHUMAN_ 6-Aug-10 0:13

_AnsHUMAN_

6-Aug-10 0:13

does it not look as simple as tokenizing the strings on ',' and getting the last character of tokenized string to store in one array and the rest of the part in another after removing \r\n. If the last character is not a \n then only you need to add it to the array containing numbers.

I am a HUMAN. I have that keyword (??? too much) in my name........
Wink | ;-)

_AnsHUMAN_b>

AbhiHcl6-Aug-10 0:24

6-Aug-10 0:24

can u please send me some sample code .

Sauro Viti6-Aug-10 0:34

6-Aug-10 0:34

As others already told you, the answer is tokenize the string alternating "," and "\r\n" as delimiters.

Nobody will give you a sample nor will do the work for you; if you don't know how to tokenize a string, look at strtok, wcstok, _mbstok (CRT)[^]

AbhiHcl6-Aug-10 0:49