C / C++ / MFC Discussion Boards

how to change a row height in a splitter window?

Joseph Marzbani15-Feb-09 7:51

15-Feb-09 7:51

I'm useing MFC and have a SDI app with Doc/View architecture. The main window has got two pane horizontally. Now I'm gonna change their height programmatically; but how? Laugh | :laugh:

Thank you masters!

Re: how to change a row height in a splitter window?

Nuri Ismail15-Feb-09 8:59

Nuri Ismail

15-Feb-09 8:59

You can use the SetRowInfo and SetColumnInfo to change the size of the splitters. Have a look at this article for more info:

http://www.codeproject.com/KB/splitter/splitterwindowtutorial.aspx?fid=14064&df=90&mpp=25&noise=3&sort=Position&view=Quick&fr=26&select=1243952[^]

Re: how to change a row height in a splitter window?

Hamid_RT15-Feb-09 21:54

Hamid_RT

15-Feb-09 21:54

See here[^].

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

strange char* compile error?

George_George15-Feb-09 7:30

George_George

15-Feb-09 7:30

Hello everyone,

Anything wrong with my code below? I got the compile error!

typedef unsigned char       BYTE;

void foo(char* & p)
{
	return;
}

int main()
{
	BYTE *              buffer;
	// error C2664: 'foo' : cannot convert parameter 1 from 'char *' to 'char *&'
	foo ((char*)buffer);

	return 0;
}

thanks in advance,
George

Re: strange char* compile error?

Alexander ^M.,15-Feb-09 7:33

Alexander ^M.,

15-Feb-09 7:33

this isnt strange as foo required char*& and not char*.

Don't try it, just do it! Wink | ;-)

Re: strange char* compile error?

George_George15-Feb-09 7:39

George_George

15-Feb-09 7:39

My confusion is reference type is the same as original type, for example when type Foo is needed, we could pass Foo or pass Foo&. So, I think then char* & is needed I could pass char*? What is wrong with my understanding? Smile | :)

Re: strange char* compile error?

Rolf Kristensen15-Feb-09 7:53

Rolf Kristensen

15-Feb-09 7:53

BYTE is an unsigned char (8 bit)

char* is a pointer (32 bit)

When converting BYTE to char* then it needs to create a temporary variable. It is not possible to make return-by-reference with temporary variables.

Instead make the conversion from BYTE to char* by using a local variable, and then pass that local variable to the function.

Re: strange char* compile error?

George_George15-Feb-09 17:02

George_George

15-Feb-09 17:02

I agree with your points, but confused. Since I am using BYTE* not BYTE.

Anyway, could you show me your code please? I think code clarifies everything. Smile | :)

regards,
George

Re: strange char* compile error?

grassrootkit15-Feb-09 22:00

grassrootkit

15-Feb-09 22:00

Where is he converting a BYTE to char*? He's converting a BYTE* to char*. In other words, unsigned char* to char*. I think there's no problem with the pointer size.

this is enough:
foo ((char*&)buffer);

Re: strange char* compile error?

Stuart Dootson16-Feb-09 1:12

Stuart Dootson

16-Feb-09 1:12

It's all to do with the semantics of casting - you can't pass a reference to something you've produced with a cast, even if the size and location of the thing is the same.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: strange char* compile error?

«_Superman_»15-Feb-09 15:44

«_Superman_»

15-Feb-09 15:44

You must call it as below

char* pp = (char*)buffer;
foo(pp);

«_Superman_»

Re: strange char* compile error?

George_George15-Feb-09 17:02

George_George

15-Feb-09 17:02

Your code fixes my issue, but why? I think both your code and my code are of the same effect. Smile | :)

regards,
George

Re: strange char* compile error?

«_Superman_»15-Feb-09 18:16

«_Superman_»

15-Feb-09 18:16

When you typecast, you have to give the destination exactly as it should be.
So you could also typecast if as foo((char*& )buffer)

«_Superman_»

Re: strange char* compile error?

Stuart Dootson16-Feb-09 1:13

Stuart Dootson

16-Feb-09 1:13

It's all to do with the semantics of casting - you can't pass a non-const reference to something you've produced with a cast, even if the size and location of the thing is the same.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

How redraw images if screen resolution changes?

Supra215-Feb-09 4:09

Supra2

15-Feb-09 4:09

hi,
I have an application which loads some images. when I changes the screen resolution position of images gets changed. How to manage image position while changing the screen resolution.

Thanks

Re: How redraw images if screen resolution changes?

Alexander ^M.,15-Feb-09 7:34

Alexander ^M.,

15-Feb-09 7:34

what images? where are they displayed? how are they displayed?

Don't try it, just do it! Wink | ;-)

Re: How redraw images if screen resolution changes?

Hamid_RT15-Feb-09 21:52

Hamid_RT

15-Feb-09 21:52

You can check new resolution with GetSystemMetrics.

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

Create a Excel ListBox from C++

Taubi15-Feb-09 3:59

Taubi

15-Feb-09 3:59

Hi,

I created an C++ application an run Excel within that application by using the COM-Interface. For the development I use Visual Studio 2005. At the moment I'm be able to create an Excel application, create a worksheet and put Data on selected cells. Just see my code example.

Excel::_ApplicationPtr ExcelApp;
ExcelApp.CreateInstance(L"Excel.Application.9");
ExcelApp->put_Visible(10, true);
Excel::_WorksheetPtr pSheet;
pSheet = ExcelApp->ActiveSheet;
pSheet->Range["C1"]->Value = "Hallo World";
ExcelApp->Quit();

Now I'm trying to create a Excel ListBox throughout my C++ application. The problem is, that I'm not a experienced programmer. By searching the internet, I couldn't found any examples which would explain how to do that. In the excel9.tlh include, I found a ListBox decleration. The problem is that I don't know how to instantiate such a struct and conect it to a defined cell.

Thanks for your help.

Detecting Server (Socket) Disconnect?

gvanto15-Feb-09 2:33

gvanto

15-Feb-09 2:33

After following the great tutorial on here: <a href="http://tldp.org/LDP/LG/issue74/tougher.html">http://tldp.org/LDP/LG/issue74/tougher.html</a>[<a href="http://tldp.org/LDP/LG/issue74/tougher.html" target="_blank" title="New Window">^</a>]

sources in folder here: <a href="http://www.sharedigest.com/SocketClientServer.zip">http://www.sharedigest.com/SocketClientServer.zip</a>[<a href="http://www.sharedigest.com/SocketClientServer.zip" target="_blank" title="New Window">^</a>]

I've managed to get the client and server talking to each other.

This is for an setup whereby data will be transmitted to my client via telnet from a remote server, and, according to them, I need to configure the client in such a way that it checks if the server dies and automatically attempts to reconnect after some (pre-specified) time period.

Currently, when I kill the server, I get ALOT of '' received by the client, continuously ... (output shown below, main routine shown below output)

I was wondering if there's a way to detect that the connection from the server's been lost, and consequently attempt to reconnect and keep listening for incoming messages?

Help much appreciated!
gvanto
socket newbie

<code>
Server:
pacific@mainbox Unsure | :~

/workspace/SocketClientServer/Debug$ ./SocketClientServer 0
starting server ...
Hello server from client.
Please enter string to send: hello back to client
Please enter string to send: another message
Please enter string to send: one more
Please enter string to send: //here i kill the server using ctrl+c

Client:
pacific@mainbox Unsure | :~

/workspace/SocketClientServer/Debug$ ./SocketClientServer 1
starting client ...
Sending hello server msg ...
Listening ...
We received this response from the server:
"hello back to client"
Listening ...
We received this response from the server:
"another message"
Listening ...
We received this response from the server:
"one more"
Listening ...
We received this response from the server: //AFter server killed, FLOOD of incoming BLANK messages received by client
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:
""
Listening ...
We received this response from the server:

</code>

MAIN ROUTINE:
<code>

/*
* main.cpp
*
* Created on: 15/02/2009
* Author: pacific
*
* http://tldp.org/LDP/LG/issue74/tougher.html
*/

#include <iostream>
#include <cstdlib>
#include <stdio.h>
#include <string>
#include <stdlib.h>

#include "ServerSocket.h"
#include "ClientSocket.h"
#include "SocketException.h"

#define DO_MAIN 1

using namespace std;

#ifdef DO_MAIN
int main(int argc, char *argv[]) {

if(argc > 1) {
/*****************************************************
* *********** SERVER *******************************/
if(atoi( argv[1] ) == 0) { //server mode
cout << "starting server ... " << endl;

try {
//Create the server socket
ServerSocket *server = new ServerSocket(30000); //set up socket and listen on local port

while(true) { //wait for incoming connections

/**
* Contains all of our socket information, used to exchange data with the client.
*/
ServerSocket new_sock;
server->accept(new_sock); //accept new incoming socket connection

try {
while(true) {
string data;
new_sock >> data; //read data from new_sock into 'data'
cout << data << endl;
//new_sock << data; //sends data in 'data' back throught the socket to the client (echo server)

string sendstr;
while(1) {
cout << "Please enter string to send: ";
getline (cin, sendstr);
new_sock << sendstr; //send it!
}

}
}
catch(SocketException&) {}
}

}
catch(SocketException &e) {
std::cout << "Exception was caught:" << e.description() << "\nExiting.\n";
}

}

/*****************************************************
* *********** CLIENT *******************************/
if(atoi(argv[1]) == 1 ) { //client mode
cout << "starting client ... " << endl;

try {
//Create the server socket
ClientSocket client("localhost", 30000); //set up socket and listen on local port
string reply;

try {
cout << "Sending hello server msg ... " << endl;
client << "Hello server from client. "; //send
}
catch(SocketException &) {}

while(true) { //keep listening

try {
cout << "Listening ... " << endl;
//client << "Test message. "; //send
client >> reply; //receive
}
catch(SocketException &) {}

std::cout << "We received this response from the server:\n\"" << reply << "\"\n";;
}
}
catch(SocketException &e) {
std::cout << "Exception was caught:" << e.description() << "\nExiting.\n";
}

}

}
else {
cout << "usage: ./SocketClientServer 0|1 (0 == server, 1 == client)" << endl;
}

return 0;
}

#endif

</code>

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http://www.WebCV.com.au

Re: Detecting Server (Socket) Disconnect?

Stuart Dootson15-Feb-09 3:09

Stuart Dootson

15-Feb-09 3:09

Go back to Beej's networking guid that you were looking at a few days ago - that says this in the section about recv

Wait! recv() can return 0. This can mean only one thing: the remote side has closed the
connection on you! A return value of 0 is recv()'s way of letting you know this has occurred.

[edit]I'd modify the ClientSocket class to do something like throw an exception on getting a return value of zero from recv.[/edit]

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Detecting Server (Socket) Disconnect?

gvanto16-Feb-09 17:26

gvanto

16-Feb-09 17:26

Thanks alot, think the recv() == 0 should do the trick.

I've set it up to be reconnecting every somany seconds, when it does it keeps listening.

Many thanks again guys,

onto threads now! Smile | :)

(multiple clientsockets within class)

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Re: Detecting Server (Socket) Disconnect?

Eytukan15-Feb-09 5:48

Eytukan

15-Feb-09 5:48

It simply sucks to go through the junk. Please remove it.

Also, to answer your question, based on my guess, I think you are not talking about a natural disconnect between server & client. TCP is connection oriented, when one breaks it , you should get an exception. But there's one exception, when there's a slight network disruption, the server actually loses it's connection with client, but it acts to be there alive. The client gets notified but the server don't. even the send function wouldn't convey us anything.That's a problem. There we need to set up a ping mechanism. The server asks "Are you all alive".. the clients say "Yes we are". If few client's don't say, they are actually out. We need to remove them from association with server.

I don't remember the scenario so clearly. I did these long before. I'm not sure If I'm right :P. A couple of years before I replied to the same question with a more vivid answer. lol memory's fading. Sigh | :sigh:

OK,. what country just started work for the day ? The ASP.NET forum is flooded with retarded questions. -Christian Graus

Best wishes to Rexx[^]

error MIDL2020 : error generating type library : SaveAllChanges Failed :

pandit8415-Feb-09 0:19

pandit84

15-Feb-09 0:19

Please tell me what will the cause for this.
i have checked the path for MIDL compiler also. Please help

Re: error MIDL2020 : error generating type library : SaveAllChanges Failed :

Nuri Ismail15-Feb-09 0:49

Nuri Ismail

15-Feb-09 0:49

This error can occur in many cases:

- The type library could not be generated. One possible cause of this error is specifying a path to the IDL file that is longer than 126 characters. Oleaut32.dll does not support path names longer than 126 characters.

- Another way to get this message is to have the .tlb file write-protected, as you do when you use a code management tool...

I think that you first have to check your .tlb files if you use some code management tool

fatal error C1189: #error : This add-in is for VC++ 6.0 only

pandit8414-Feb-09 23:18

pandit84

14-Feb-09 23:18

I am getting an error as said in the subject line . I know this is because i am porting my code from VC 6.0 to .NET 2005. But dont know how to troubleshoot this problem. Can you please tell me is there any setting required for this ...because my other adddins are building properly except for one i am getting such an error.

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