C / C++ / MFC Discussion Boards

Re: about STATIC TEXT in WIN32 API (C++ only)

Hamid_RT19-Oct-07 19:09

Hamid_RT

19-Oct-07 19:09

You can use of WM_SETTEXT message.

Midistation Directx

Rance_Wilson19-Oct-07 6:56

Rance_Wilson

19-Oct-07 6:56

Need help with Midistation...I want to write a FUNCTION in Visual C++ that will SET A FLAG to turn note on when note turns off...
DIRECTX DIRECT MUSIC
IF NOTE = OFF
THEN NOTE = On

What MIDISTATION source do I use from the MIDISTATION FOLDER????

I'm using MIDISTATIONDIG.CPP FILE..Is This correct???

//////////////////////////////////////////////////////////
Function called when the keyboard sends a note to the port
IF NOTE = OFF THEN NOTE = ON
/////////////////////////////////////////////////////////

Rance_Wilson

DIRECTX DIRECT MUSIC MIDISTATION MIDI

Rance_Wilson19-Oct-07 6:49

Rance_Wilson

19-Oct-07 6:49

Need help with Midistation...I want to write a FUNCTION in Visual C++ that will SET A FLAG to turn note on when note turns off...

IF NOTE = OFF
THEN NOTE = On

What MIDISTATION source do I use from the MIDISTATION FOLDER????

I'm using MIDISTATIONDIG.CPP FILE..Is This correct???

//////////////////////////////////////////////////////////
Function called when the keyboard sends a note to the port
IF NOTE = OFF THEN NOTE = ON
/////////////////////////////////////////////////////////

Rance_Wilson

c++ options

paulie5419-Oct-07 6:22

paulie54

19-Oct-07 6:22

hi would like to know if the following is possible:

a windows program written in c++ that allows you to submit a form and store the contents of the form in a database and retrieve/edit/delete information in the database. i can do this in asp, but would like to create an c++ application that does the same thing

if not is there another way to achieve a windows standalone application

regards
very new to c++ programming

Re: c++ options

Mark Salsbery19-Oct-07 6:24

Mark Salsbery

19-Oct-07 6:24

Yes, it's possible.

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

Re: c++ options

Nemanja Trifunovic19-Oct-07 6:38

Nemanja Trifunovic

19-Oct-07 6:38

It is possible, but if you are very new to C++ and experienced with ASP, better use something like VB (I can't believe I wrote that Dead | X|

)

Programming Blog
utf8-cpp

Re: c++ options

Jonathan [Darka]19-Oct-07 7:21

Jonathan [Darka]

19-Oct-07 7:21

Nemanja Trifunovic wrote:
I can't believe I wrote that

I don't think any of us can believe you said that!

Smile | :)

Jonathan Wilkes
Darka[Xanya.net]

Re: c++ options

BadKarma19-Oct-07 7:39

BadKarma

19-Oct-07 7:39

I'm expecting sincere apologies Wink | ;)

codito ergo sum

Re: c++ options

Hamid_RT19-Oct-07 6:58

Hamid_RT

19-Oct-07 6:58

Yes possible.;)

Crash in CAsyncSocket::Close()

Anorexic Tribble19-Oct-07 2:19

Anorexic Tribble

19-Oct-07 2:19

I am writing a short piece of code to broadcast a UDP packet over a network. It initialises the socket system, created a DGRAM socket, broadcasts the packet and then closes the socket. My problem is that when the Close() function is called it crashes with the message

HEAP[Test.exe]: Invalid Address specified to RtlFreeHeap( 01470000, 0147425C )

Here is the snippit of code :

#define BROADCAST_PORT           9122<br />
<br />
   CAsyncSocket         m_Broadcast_Socket;<br />
   char  Data[] = "1234567890";<br />
   int   Bytes_Sent;<br />
   BOOL  Value;<br />
<br />
<br />
      AfxSocketInit();<br />
<br />
      VERIFY(m_Broadcast_Socket.Create(BROADCAST_PORT, SOCK_DGRAM));<br />
      Value = TRUE;<br />
      VERIFY(m_Broadcast_Socket.SetSockOpt(SO_BROADCAST, &Value, sizeof(BOOL)));<br />
      Bytes_Sent = m_Broadcast_Socket.SendTo((LPCTSTR)Data, 3, BROADCAST_PORT);<br />
      DWORD Error = GetLastError();<br />
      m_Broadcast_Socket.Close();

I can see the packet on my network monitor.

If I take out the SendTo call I have no crash.

If I take out the Close call the destructor crashes (again in the Close call).

What am I doing wrong ?

Re: Crash in CAsyncSocket::Close()

led mike19-Oct-07 4:15

led mike

19-Oct-07 4:15

Anorexic Tribble wrote:
What am I doing wrong ?

One guess is that you did not call Shutdown(..) and the other thing I would note is that you are using an Asynchronous Socket in serial fashion.

Are you following a book, article or tutorial? If so please reference it.

Re: Crash in CAsyncSocket::Close()

Anorexic Tribble19-Oct-07 4:37

Anorexic Tribble

19-Oct-07 4:37

I put in the Shutdown call, but that made no difference. It be honest at the moment my small routine is the only thing sending and nothing receiving (at the moment). But good idea to put Shutdown call in.

I used an async socket because eventually I will be sending and receiving in a non linear fashion.

I'm using bits and pieces from various articles. To be honest I haven't found a really good one that deals specifically with DGRAM sockets. MSDN for example mixes its description of DGRAM and STREAM sockets to provide a very confusing piece if spaghetti writing. Do you know of any good articles?

Re: Crash in CAsyncSocket::Close()

led mike19-Oct-07 5:24

led mike

19-Oct-07 5:24

This place[^] has been around since the 90's and is always a good source to check out.

Copying from unsigned char * to the CString

ashishbhatt19-Oct-07 2:01

ashishbhatt

19-Oct-07 2:01

Hi All,

I have unsigned char * buffer in which some data are stored , now I want to move these all data to my CString variable for some operations.

I tried to copy but problem is that in my unsigned char * some data are padded as zero, So I hope that in CString it gets the null value so it can not copy whole data.

I tried to copy from unsigned char * to the CString using...

CString tmpMsg = CString(msg); // Here msg is the unsigned char *

Ashish Bhatt

Re: Copying from unsigned char * to the CString

john563219-Oct-07 2:11

john5632

19-Oct-07 2:11

try memcpy()

Re: Copying from unsigned char * to the CString

ashishbhatt19-Oct-07 2:23

ashishbhatt

19-Oct-07 2:23

Thanks ...

I used memcpy() as u told me, But I used like ........

memcpy(&tempMsg,(unsigned char*)msg,noOfBytes);

Then it gives me the run time Access violation error as below...

TestRTMP.exe: 0xC0000005: Access violation reading location 0x49468964.

So,plz help me , is there any other way to copying.

Ashish Bhatt

Re: Copying from unsigned char * to the CString

Tydia-kun19-Oct-07 3:50

Tydia-kun

19-Oct-07 3:50

Does not surprise me that it gives you an access violation when doing that.
The first and foremost rule to remember is: DO NOT USE MEMCPY ON CLASSES.
Classes work independently, managing their own memory and so on. Therefore, you should use the exposed interfaces in the classes to do stuff.
In this case, you're overwriting important data in the class, not to mention that the class's internal buffer is nowhere large enough to hold your data.
As mentioned, use CString.GetBuffer(LengthOfBuffer). It returns a pointer to a buffer. Copy data using memcpy/CopyMemory. Then call CString.ReleaseBuffer(LengthOfData).
That should do the trick.

Re: Copying from unsigned char * to the CString

Nishad S19-Oct-07 2:13

Nishad S

19-Oct-07 2:13

Actually you just need to keep the data in CString? Then use GetBuffer, and copy the data using CopyMemory. But remember, you should not perform any string operations because it is having null characters...

- NS -

Re: Copying from unsigned char * to the CString

James R. Twine19-Oct-07 7:13

James R. Twine

19-Oct-07 7:13

The CString class is designed to handle C-style strings, meaning strings that are terminated with a character value of zero (AKA NUL). It is not designed to handle raw data that contains embedded NUL characters, not double-NUL-terminated collections of strings.

Sounds like you may be a bit too comfortable with CStrings... Smile | :)

-=- James
Please rate this message - let me know if I helped or not!<HR>If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Avoid driving a vehicle taller than you and remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
See DeleteFXPFiles

how to draw a dynamic curve

nibabug19-Oct-07 0:31

nibabug

19-Oct-07 0:31

i want to lern to draw a dynamic curve,but do not know how to do;
is there any good Activecontrol or methode,

my idea is, continuesly get data from a database or by some way else, then draw them on a picture, the curve should be dynamic.

thanks a lot

wuhuaiji

Re: how to draw a dynamic curve

jhwurmbach19-Oct-07 0:45

jhwurmbach

19-Oct-07 0:45

What is your problem?
In OnDraw(), you draw the curve (MoveTo(), LineTo()) into the client rect. Whenever you get new data and fell the need to redraw, you Invalidate().

Let's think the unthinkable, let's do the undoable, let's prepare to grapple with the ineffable itself, and see if we may not eff it after all.
Douglas Adams, "Dirk Gently's Holistic Detective Agency"

Re: how to draw a dynamic curve

nibabug19-Oct-07 0:51

nibabug

19-Oct-07 0:51

hello
thanks for your answer
my problem is, how to make the curve move smoothly? it move from right to left with time going

wuhuaiji

Re: how to draw a dynamic curve

jhwurmbach19-Oct-07 0:56

jhwurmbach

19-Oct-07 0:56

Do you want algorithms to interpolate and smooth the curve-data?
Or do you want to reduce flicker on the screen?

Either case, there are articles here on codeproject and on the net.
E.G. here[^].

Re: how to draw a dynamic curve

chandu00419-Oct-07 0:48

chandu004

19-Oct-07 0:48

have you googled to for "Active X Control to draw a curve"
there are somany articles and active X controls related to that topic.
or if you want to develop one active X control, then i can guide you.

Re: how to draw a dynamic curve

Hamid_RT19-Oct-07 0:57

Hamid_RT

19-Oct-07 0:57

But why he must uses of Activexs control?

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