OnReceive is not getting called, Why? - C / C++ / MFC Discussion Boards

GANsJob26-May-06 2:24

26-May-06 2:24

I use a table named FDetails with 4 text fields and a datetime field named date in MSaccess
when insert values into table ising ado recordset obj I receive some syntax error
recordset->Open("INSERT INTO FDetails(name,path,duration,volume,date) VALUES('hello','location','duration','vol','12/12/2000')",connection.GetInterfacePtr(), ADODB::adOpenForwardOnly,ADODB::adLockReadOnly, ADODB::adCmdText);

any one know inserting date into table

Re: ado in vc++

David Crow26-May-06 2:35

David Crow

26-May-06 2:35

GANsJob wrote:
when insert values into table ising ado recordset obj I receive some syntax error

And that error would be what?

"The largest fire starts but with the smallest spark." - David Crow

Re: ado in vc++

GANsJob26-May-06 2:45

GANsJob

26-May-06 2:45

the error is
syntax error in insert into statement

Re: ado in vc++

David Crow26-May-06 3:13

David Crow

26-May-06 3:13

See here.

"The largest fire starts but with the smallest spark." - David Crow

Re: ado in vc++

Milton Karimbekallil26-May-06 2:39

Milton Karimbekallil

26-May-06 2:39

Try change the field name 'date' to 'date1'. If I remember correctly, date is a reserved word in ms access.

cheers..milton kb.

Calling VB function in Win32 Dll

Arun Tayal26-May-06 1:30

Arun Tayal

26-May-06 1:30

Hello All,

I am using a Win32 regular Dll . I want to call a function written in VB application using function pointers.

The snippet from Win32 dll is as follows:

typedef int (*pt2Function)(char*);

pt2Function Objectpt2Function;

EXPORT int PASCAL PassPtr(int (*pt2Func)(char*))
{
pt2Func("arun");
return 1;
}

The Snippet from VB Application is as follows:

Public Sub Callbackfuntion(ByVal str1 As String)

MsgBox "Callbackfuntion"
End Sub

x = PassPtr(VarPtr(Callbackfuntion))

This all results in the application crash....
Can anyone suggest me a solution how I can call this function??

Thanks in Advance

Arun Tayal

Re: Calling VB function in Win32 Dll

Milton Karimbekallil26-May-06 2:13

Milton Karimbekallil

26-May-06 2:13

You cannt call a VB function from c++ without using COM, because all vb dlls are com components. SO the typical win32 dll function call approch using typedef wont work here. You cave to use

#import yourvbcomponent.dll <br />
<br />
CoInitilaize(NULL) //initialize com runtime<br />
yourvbcomponentLib::_vbclassPtr clsPtr(yourvbcomponentLib::vbclass)//cocreate an instance of ur vb class<br />
<br />
CString msg = "tst msg";<br />
BSTR bstr = msg.AllocSysString();<br />
clsPtr->Callbackfuntion(bstr);<br />
SysFreeString(bstr);<br />

cheers....milton.

OnReceive is not getting called, Why?

syntaxed26-May-06 1:23

syntaxed

26-May-06 1:23

Im trying somewhat simplest idea of sockets app using multicast.

Following is what SockApp1 does:
1) OnButtonCreate() creates the port, default OS assigned port. Create(0, SOCK_DGRAM)

m_pUDPSocket->Create(0, SOCK_DGRAM);

2) When OnButtonInitMulti() the mutlicast group(ip/port) is initialized.

// set up destination address <br />
memset(&m_addrMulti,0,sizeof(m_addrMulti));<br />
m_addrMulti.sin_family		=AF_INET;<br />
m_addrMulti.sin_addr.s_addr	=inet_addr(MULTIADDR);<br />
m_addrMulti.sin_port		=htons(MULTIPORT);

3) When OnButtonSend()it sends the data to the group.

SendTo(m_sendBuffer, m_sendBuffer.GetLength(), <br />
(const SOCKADDR* )&m_addrMulti, sizeof(m_addrMulti));

SockApp2 with following buttons clicked:
1) OnButtonCreate() creates the port, default OS assigned port. Create(0, SOCK_DGRAM)

m_pUDPSocket->Create(0, SOCK_DGRAM);

2) OnButtonJoinMulti() joins the multicast group.

ip_mreq mreq;<br />
memset(&mreq, 0, sizeof(ip_mreq));<br />
mreq.imr_multiaddr.s_addr = inet_addr(MULTIADDR);<br />
mreq.imr_interface.s_addr = htonl(MULTIPORT);<br />
<br />
if(SOCKET_ERROR == SetSockOpt(IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)))<br />
{<br />
	AfxMessageBox("Error: Unable to add membership");<br />
	return -1;<br />
}

here...

#define MULTIADDR	"224.0.1.129"<br />
#define MULTIPORT319	5009

Now, SockApp1, when i click onto the Send button, OnButtonSend() shud get called in which im doing the SendTo() thing. Uptill here the App1/App2 both are working fine, and the data is being sent successfully, this im sure.

The problem is, that SockApp2, which joined the group, is unable to receive the data being sent from SockApp1.

Now, SockApp1 and SockApp2 are actually a single app, called SockApp. I added SockApp1/2 names just for the clarity of the question and understanding.

At this moment, im just wondering... why SockApp2 is not receiving the data from SockApp1??? Sigh | :sigh:

Any ideas why? WTF | :WTF:

Best regards,
JT!

Re: OnReceive is not getting called, Why?

syntaxed27-May-06 5:36

syntaxed

27-May-06 5:36

any one???

Best regards,
JT!

Assertion error

Anu_Bala26-May-06 1:20

Anu_Bala

26-May-06 1:20

I got error as follows
_CrtISValidHeapPointer(pUserData)

as assertion error what is that?any one help me

Re: Assertion error

Hamid_RT26-May-06 1:24

Hamid_RT

26-May-06 1:24

Can you be more specific please

whitesky

Re: Assertion error

Anu_Bala26-May-06 1:29

Anu_Bala

26-May-06 1:29

Just file reading i am reading,the whole coding is going process fine,but after InitInstance the control goes to disassembly and shows this error and sometimes unhandled exception error is also coming.

Re: Assertion error

Hamid_RT26-May-06 1:35

Hamid_RT

26-May-06 1:35

can you show your code that has error,please

whitesky

Re: Assertion error [modified]

Stephen Hewitt26-May-06 1:55

Stephen Hewitt

26-May-06 1:55

It means you're trying to delete (or free or some other heap allocation function) memory you shoudn't. Possible reasons;
- Freeing already freed memory;
- Freeing memory not allocated on the heap;
- Freeing an address in the middle of a heap block (e.g. delete ((new int[2])+1);).

Steve

Re: Assertion error

David Crow26-May-06 2:36

David Crow

26-May-06 2:36

What line of what file is asserting? Without context, the error is rather meaningless.

"The largest fire starts but with the smallest spark." - David Crow

Re: Assertion error

Dennis Gourjii26-May-06 2:45

Dennis Gourjii

26-May-06 2:45

_CrtISValidHeapPointer(pUserData)

To find out what's wrong with this line, declare pUserData as constant pointer and see where you get compiler errors. Wink | ;)

Re: Assertion error

Bram van Kampen28-May-06 14:13

Bram van Kampen

28-May-06 14:13

An assertion is something the System Uses,(and you should also use them) to make sure that an assumption is actually the case. If it is not, it will throw an exception. In this case, if you use free(p), it assumes that p is a valid heap pointer. That assumption is tested, or asserted deep in the bowels of the code, and in this case it failed, pUserData is NOT a valid heap pointer.
Go back on the Call Stack to find out what is being freed, and take it from there

LateNightsInNewry

backwards compatibility

palako26-May-06 1:17

palako

26-May-06 1:17

Hi.

I'm coding a c++ dll with visual studio 2005 and in my project configuration properties, the Common Language Runtime Support is set to "no".

What I want is to get executables which may run in every windows machine without the need of the .NET framework, and I was wondering if I'd need another IDE to do that.

Also I'm having problems mixing up a VB 6 program which uses a c++ dll compiled with vs2005. When I run the vb executable, it holds in the process list once it's close. Nevertheless, if I compile the same VB code with vs2005 and use it with the same dll, it all works like a charm.

If you don't know the answer, clues and tips are also welcome.

Thanks in advance.

Re: backwards compatibility

Milton Karimbekallil26-May-06 2:31

Milton Karimbekallil

26-May-06 2:31

You can write a component without .net frame work support using .net 2005 IDE. whatever settings u had given is correct only.

Regarding the vb6 issue, first of all i dont understand how could u compile vb6 application using .net2005. Because 2005 will convert ur vb6 project to a .net project which uses .net framework.

If u have process hanging issue with 2005 compiled dll, then it is better you go for vc++6 ide and compile the dll over there. The diffrence in C Runtime used by 2005 and vb6 can cause this problem. I auusme vb6 runtime will use C Runtime, not your vb6 application.

cheers...milton kb

System Idle State

aks.26-May-06 0:47

aks.

26-May-06 0:47

Hi,
I want to check the system idle state, and want to do some operations on the idle time.

I had created a thread to check the system idle state.
My idle state conditions are
1. CPU usage must be less than 10%
2. There must be no load on the hard disc.

First condition is ok( I can use GetSystemTimes() to get the idle time...pls mention if any other suggessions )
But how can I check the hard disc load?

Regards,
Ajay D'Oh! | :doh:

Re: System Idle State

Garth J Lancaster26-May-06 1:10

Garth J Lancaster

26-May-06 1:10

Im sure there are one (or more) performance counters that you can use for disk activity, if not, WMI might be able to help

'g'

Re: System Idle State

aks.26-May-06 1:50

aks.

26-May-06 1:50

yes u r rt and thanks 4 ur suggession.
I can use PDH APIs. But I want to know is there any way other than using PDH APIs.
And u mentioned about Windows Management Instrumentation. I don't have much knowledge abt it. Can u pls help me?

Regards,
Ajay D'Oh! | :doh:

Re: System Idle State

David Crow26-May-06 2:38

David Crow

26-May-06 2:38

Ajaywinds wrote:
I had created a thread to check the system idle state.

Why not just use GetLastInputInfo()?

"The largest fire starts but with the smallest spark." - David Crow

Re: System Idle State

aks.26-May-06 4:06

aks.

26-May-06 4:06

thanks 4 ur suggession.
Can u pls tell me how can I check the HDD load( other than PDH APIs )

Regards,
Ajay D'Oh! | :doh:

Re: System Idle State

PJ Arends26-May-06 8:38

PJ Arends

26-May-06 8:38

Why not do the processing in a subthread created with the THREAD_PRIORITY_IDLE thread priority?

You may be right
I may be crazy
-- Billy Joel --

Within you lies the power for good, use it!!!

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