C / C++ / MFC

Re: Easy question, but im stuck. :)

16-Jul-02 5:26

How do I get the contents of CString m_strData into BYTE* m_pData?

I have a edit box that has a member variable of m_strData, and I need to get the string into the m_pData variable.

Thanks Smile | :)

Re: Easy question

Schnemar16-Jul-02 6:04

Schnemar

16-Jul-02 6:04

try this one:

CString strTemp = "Hello World";
BYTE* pByte = (BYTE*) (LPCTSTR) strTemp;

MS

Re: Easy question

Daniel Turini16-Jul-02 8:34

Daniel Turini

16-Jul-02 8:34

NO!!! This is dangerous!

You need to do this:

CString strTemp = "Hello World";
BYTE* pByte = (BYTE*) strTemp.LockBuffer();

and when pByte is not needed anymore:

strTemp.UnlockBuffer();

Never cast away the const-ness of a pointer...

Concussus surgo.
When struck I rise.

Gary Kirkham16-Jul-02 8:02

Gary Kirkham

16-Jul-02 8:02

What Martin suggested sets m_pData to point to m_strData. I interpret your question as...You want to copy the contents of m_strData to m_pData(which is already allocated).

If so you could use memcpy
or
strcpy and cast m_pData to a char*

Gary Kirkham

A working Program is one that has only unobserved bugs

Re: Easy question, but im stuck. :)

Anonymous16-Jul-02 9:37

16-Jul-02 9:37

Yes I wanted to copy the string thats held in m_strData into m_pData.. I used his suggestion and it worked fine.. I just saw the second post and will adjust my code...

Thanks everyone!

basic socket question

Anonymous16-Jul-02 4:46

16-Jul-02 4:46

I am not an experienced sockets programmer, so I think I am missing something very basic. All of this is for UDP messages only.

I have a program that has two sockets set up. 1 for sending, and one for listening.

The sender is created by using the INADDR_ANY IP, and a specific port number (1594).

The listener is created by using the INADDR_ANY IP, and 0 as the port number.

This has been working for years with no problems.

I recently had to add the ability to send a broadcast UDP packet, but with a specific source address (the default would have picked the primary NIC source address, and this was causing problems).

Sending broadcasts is not the problem. This has been working for years also. It was the part where the source IP needs to be specified where problems came in.

I created another socket that uses a specific IP (10.3.2.1) as the IP, and 0 for the port number (letting a port get picked automatically). I send the message, then close the socket.

The message gets sent correctly, and a response does come back (using a sniffer to see this).

The problem is that my listener socket does not see the reply.

Since the only addition to the otherwise working application was the new (temporary) socket to send the broadcast, I'm wondering why this reply is not seen by the listener socket?

I'm hoping someone will be able to see a basic flaw in my thinking.

Thanks.

Mike Nordell16-Jul-02 5:15

Mike Nordell

16-Jul-02 5:15

Anonymous wrote:
The problem is that my listener socket does not see the reply.

Do you really try to recieve from the right interface? Have you called bind to bind the listening socket to the interface the data is really coming in on, or are you just listening on the "default" interface?

Anonymous16-Jul-02 6:01

16-Jul-02 6:01

The bind for the listening socket is passed the ANY_ADDR, and 0 for the port number. When I do a recvfrom on this type of bind, does this rcv everything, or only messages that haven't been directed to other more specific binds?

Thanks again.

JohnnyG16-Jul-02 12:53

JohnnyG

16-Jul-02 12:53

I'm a little confused following your story and I am no expert either but I have written some small apps in VB to send and receive UDP datagrams. You must be using some sort of user defined 2-way UDP communication cause I don't know what you meant about a reply.

Anonymous wrote:
The listener is created by using the INADDR_ANY IP, and 0 as the port number.

Doesn't the listening port number have to be the same as the transmit port?

In my apps, one box sends UDP broadcast using port XYZ, my other app listens using port XYZ. Of course they both have to be on the same subnet. I tried before using different subnets and it wouldn't work.

making a toolbar button invisible

Dave_17-Jul-02 3:14

Dave_

17-Jul-02 3:14

The listener needs to catch messages comming from multiple ports, and this part has been working for quite a while.

The architecture is not standard, and this is probably confusing. The sender, and the listener are in separate threads, and don't really interact with eachother.

I guess than main question is:
What happens when you bind a socket to INADDR_ANY, and port 0 (meaning all ports), and when you have another socket bound to 10.3.2.1, and port 0?
In this case does the first socket still rcv messages sent to 10.3.2.1, or are they going to be directed to the second socket, since it is more specific? To confuse things even more, what happens when I close the second socket? It looks like any messages will get returned a Destination Port Unreachable error message (ICMP).

Thanks for your reply.

AfxGetResourceHandle

Jose Vicente16-Jul-02 4:35

Jose Vicente

16-Jul-02 4:35

I'm working in an ActiveX and I'm trying to load a Menú using CMenu.LoadMenu.
The problem is that AfxGetResouceHandle returns NULL and I have no idea why. Can anyone help me ?? Confused | :confused:

Re: AfxGetResourceHandle

joblemar16-Jul-02 5:09

joblemar

16-Jul-02 5:09

I have solved the problem, I add this line
AFX_MANAGE_STATE(AfxGetStaticModuleState())

ns16-Jul-02 4:21

16-Jul-02 4:21

Two things:

1.At design time, how do I make certain toolbar buttons invisible (I dont want to delete them in case I need them later)

2. How do I dynamically make a toolabr buton invisible at runtime? What code do I need. I tried:
void CFormViewMDIView::OnToolbarup()
{
GetDlgItem(ID_TOOLBARDOWN)->ShowWindow(SW_HIDE);
}

but it crashed.

Thanks for the help,
ns

Rage16-Jul-02 4:51

Rage

16-Jul-02 4:51

First, check this FAQ

Then, try this (I´ve already posted that once, but i am still not sure it works)

Create a CtoolbarCtrl object, assign it the return value of pBar->GetToolbarCtrl where pBar is a *Ctoolbar. Then you have access to the EnableButton() and other functions of the same kind using the CtoolbarCtrl.

Just tell me if it works ...

~RaGE();

Shog⁹16-Jul-02 7:19

Shog⁹

16-Jul-02 7:19

m_pToolBar->GetToolBarCtrl().HideButton(ID_TOOLBARDOWN, TRUE);

Where m_pToolBar is a pointer to a CToolBar object, and ID_TOOLBARDOWN is the ID of the button you wish to hide.

--------

PMGRE

--Shog⁹ --

ns16-Jul-02 7:44

16-Jul-02 7:44

Thank you. I'll try it. Much appreciation,
ns

ns16-Jul-02 8:07

16-Jul-02 8:07

It compiles fine, but crashes when I press the button that executes this snippet:

void CTrain1View::OnToolbarup()
{
//AfxMessageBox("Up pressed");
CToolBar * m_pToolBar;

m_pToolBar = (CToolBar*)GetDlgItem(IDR_MAINFRAME);
m_pToolBar->GetToolBarCtrl().HideButton(ID_TOOLBARDOWN, TRUE);

What am I doing wrong?

Error is memory couldnt be read...