C / C++ / MFC Discussion Boards

Re: CreateFile and Long Path/Files :: Win32

Michael Dunn27-Dec-02 19:26

27-Dec-02 19:26

kuphryn wrote:
Is there something special about creating directories with two backslashes instead of one?

The two backslashes are necessary to comply with C++ syntax. In string and character literals, a backslash is a special character and indicates that the next character should be treated specially. For instance, \t means "the tab character". One backslash by itself is meaningless*, so in order to have a backslash character in a string, you write \\ in your code.
So to create a directory C:\testing, you write "C:\\testing". If you write "C:\testing", that is interpreted as C followed by colon followed by TAB followed by "esting", which is not what is intended.

*Except when the backslash comes at the end of a line, in which case it is an instruction to the preprocessor to join the line with the following one.

--Mike--
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Re: CreateFile and Long Path/Files :: Win32

valikac27-Dec-02 20:47

valikac

27-Dec-02 20:47

Okay. Thanks.

Kuphryn

SDI Window in a MFC DLL

Datalord3227-Dec-02 10:35

Datalord32

27-Dec-02 10:35

Hi!
I wanted to create a MFC dll which displays a SDI window when I call it
whith rundll. The function is - let's say - "EntryPoint". It worked so far,
but the SDI doesn't want to stay on the screen, it just pops up and closes.
In the MSDN, I've read that a dll is being unloaded when the function I'm
calling (EntryPoint) returns. How can I make the SDI staying on the screen?
Is there a workaround or somewhat? Perhaps a wait loop which doesn't take
much processor time?

Mfg
the Datalord

Adding formatted line of text to CRichEditCtrl

IGx8927-Dec-02 10:21

IGx89

27-Dec-02 10:21

I'm adding IRC chat to my game launcher, and am wanting to show the chat text in colors using a Rich Edit 2.0 control in a dialog. I'm doing the following to add a line of text (Tmp is a CString containing the chat line text):

<br />
	CHARFORMAT cf;<br />
<br />
	cf.cbSize = sizeof(cf);<br />
	cf.dwMask = CFM_COLOR | CFM_FACE;<br />
	strcpy(cf.szFaceName,"Subway");<br />
...<br />
		cf.crTextColor = RGB(255,0,0);<br />
...<br />
	ChatList.SetSel(-1,0);<br />
	ChatList.SetDefaultCharFormat(cf);<br />
	ChatList.ReplaceSel(Tmp);<br />
	ChatList.LineScroll(ChatList.GetLineCount());<br />

Now, the text is correctly show using the "Subway" font, but it's still only black Frown | :(

What am I doing wrong?

Thanks!

Re: Adding formatted line of text to CRichEditCtrl

IGx8927-Dec-02 16:05

IGx89

27-Dec-02 16:05

Hmm, the coloring works in release builds! Confused | :confused:

i love this site !

HellShrimp4free27-Dec-02 10:17

HellShrimp4free

27-Dec-02 10:17

i love this site!
can Somebody tell me why ?

-=Ehsan-de-Burge=- Roll eyes | :rolleyes:

Re: i love this site !

Hockey27-Dec-02 11:40

Hockey

27-Dec-02 11:40

1) Easy to navigate and pleasant interface
2) Super fast message boards responses
3) Quality articles which seldomly require H scrolling
4) Emoticons are so damn cool Cool | :cool:

5) A real sense of community

"An expert is someone who has made all the mistakes in his or her field" - Niels Bohr

Re: i love this site !

Nitron28-Dec-02 5:06

Nitron

28-Dec-02 5:06

- Nitron

"Those that say a task is impossible shouldn't interrupt the ones who are doing it." - Chinese Proverb

strtok - reconstruct string after it finds a token

jimNLX27-Dec-02 10:15

jimNLX

27-Dec-02 10:15

Is there a way or another function that will work the same as STRTOK without removing the string after the token?

I want to find the first token and leave the string as it was.

Thanks,

Jim

Re: strtok - reconstruct string after it finds a token

C^hris L^osinger27-Dec-02 10:22

C^hris L^osinger

27-Dec-02 10:22

if you just want to search for a sub-string, try "strstr".

-c

I'm not the droid you're looking for.

ThumbNailer

Re: strtok - reconstruct string after it finds a token

jimNLX27-Dec-02 10:42

jimNLX

27-Dec-02 10:42

strstr would work, but I only know the string based on a delimiter.

strtok() works so well I was hoping I would have to save off the string first and then put it back in later.

Thanks...guess I'll keep searching....

Re: strtok - reconstruct string after it finds a token

Renjith Ramachandran27-Dec-02 13:27

Renjith Ramachandran

27-Dec-02 13:27

substring by using strstr()?

~~~~Code the Dreams~~~~~

Where is random() in Visual C++.net ?

HellShrimp4free27-Dec-02 9:52

HellShrimp4free

27-Dec-02 9:52

hi i searched the MSDN but i findout out that the random() function in stdlib.h is not exist.
it seems that it's replaced with srand() and rand() . can anyone explain me how can i use these 2 function or any other to reach random numbers in requested range ? (for example 0 < x < 1000 )

thnx

Re: Where is random() in Visual C++.net ?

Nish Nishant27-Dec-02 10:00

Nish Nishant

27-Dec-02 10:00

See http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclib/html/_crt_rand.asp for an example.

Nish

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Review by Shog⁹
Click here for review[NW]

Re: Where is random() in Visual C++.net ?

HellShrimp4free27-Dec-02 10:11

HellShrimp4free

27-Dec-02 10:11

thanks mr.nishant but it seems that in this example the Range of Figures are not important.
may be i should do something like this :

<br />
int r=1000;<br />
while(1){ r=rand(); if (r<999) break; }

thanks any way.

-=Fight with be Best Die like the Rest=- Big Grin | :-D

Re: Where is random() in Visual C++.net ?

S O S27-Dec-02 10:28

S O S

27-Dec-02 10:28

*cough* modulus *cough* Wink | ;)

Know that good little % operator?
I wonder what this would do:

min + (rand() % (max - min + 1))

Re: Where is random() in Visual C++.net ?

Nick Parker27-Dec-02 11:04

Nick Parker

27-Dec-02 11:04

HellShrimp4free wrote:
but it seems that in this example the Range of Figures are not important.

Correct, in the MSDN example the range isn't important, however you can do the following to limit your range to under 1000:

#include "stdafx.h"

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

#using <mscorlib.dll>
#include <tchar.h>

using namespace System;

// This is the entry point for this application
int _tmain(void)
{
   srand( (unsigned)time( NULL ) );
   for( int i = 0;   i < 10;i++ )
      printf( "  %6d\n", rand()%1000 );
   Console::Read();
}

Nick Parker

You see the Standards change. - Fellow co-worker

Re: Where is random() in Visual C++.net ?

UrbanBlues27-Dec-02 22:11

UrbanBlues

27-Dec-02 22:11

Hi

Those two functions have always been there. In fact I never used (saw ?) the function Random()

Here is how to use them:

// Seed Random-number Generator with Current Time
srand(( unsigned) time(NULL ));

int nRandomData = rand() % 4;

Replace 4 with the Maximum value accepted (1000 in your request)

The call to srand with current time allows the generation of different random sequences. If you start always with the same number, you always got the same sequence ( as far as I remember) ...

HTH

Thierry

Optimizing a pooling mechanism...

Matt Gullett27-Dec-02 9:29

Matt Gullett

27-Dec-02 9:29

I have a Windows NT service which maintains a pool of objects. The purpose of the pool is to improve performance because the objects being pooled require a signifigant amount of time for construction.

At any given time, there can be from 0-N requests for objects from the pool. There are times when the pool will have no requests at all for days. Other times, it will have 1000s of requests an hour/minute. I keep track of # of requests, avg time between requests, first request, last request, time to allocate, time to fill request, peak objects in pool, peak requests per sec/min, # of requests made when pool was exausted.

I am looking for an algorithm that will limit the number of requests that occur when the pool is exausted while not exceeding a maximum pool size or memory usage. There really is not MAX size, but I don't want to just allocate 1000s all the time. My goal would be to have 75-85% of requests filled by the pool with no waiting.

Currently, the algorithm I use is something like this:

(Pseudocode Smile | :)

long lDesiredPoolSize = lMinSize;

// NOTE: I multiply by 1.25 to give myself a 25% cushion

// if the last 5 minutes are more active than the hour, use last 5 minutes
if (lRequestsLast5Minutes > (lRequestsLastHour / 12) && lRequestsLast5Minutes > lDesiredPoolSize)
   lDesiredPoolSize = lRequestsLast5Minutes * 1.25;

// if we are getting many pool-exausted scenarios, base off this
if (lPoolExaustedRequests > lDesiredPoolSize)
   lDesiredPoolSize = lPoolExaustedRequests * 1.25;

// if activity last hour >= activity at peak, use peak
if (lRequestsLastHour >= lRequestsAtPeak)
   lDesiredPoolSize = lRequestsLastHour * 1.25;

// make sure we don't exceed the max
if (lDesiredPoolSize > lMaxPoolSize)
   lDesiredPoolSize = lMaxPoolSize;

// if no requests in past hour, empty pool
if (lRequestsLastHour == 0)
   lDesiredPoolSize = 0;

I just made this up and tinkered with it, but I wonder if anyone in CPland has any more experience with this kind of thing?

CSliderCtrl and textout

ns27-Dec-02 9:01

27-Dec-02 9:01

I get the position of the slider and do a textOut with it. After the slider reaches a 100, and the text says 100, when I slide it back, a part of the last zero doesnt get cleaned off the screen and the textout looks like:

34 ) etc.

How do I make the remnants of the prev numbers go away? I thought of doing an Invalidate() after the textout but then the number totally vanishes (because its not being written out in OnDraw() but in OnHScroll. In HScroll I get the pointer to the scrollbar, so I can GetPos. How would I access this getPos in OnDraw(0 so that I could see the refreshed text?

Appreciate your help,
ns

Re: CSliderCtrl and textout

PJ Arends27-Dec-02 9:41

PJ Arends

27-Dec-02 9:41

Draw a couple spaces after the number? (ie "34 ")

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Re: CSliderCtrl and textout

ns27-Dec-02 9:45

27-Dec-02 9:45

Wow!

I did 
s.Format("%d    ", position);

and that took care of it!
Thanks!!!

Appreciate your help,
ns

MDI: Single Doc, Multiple Views

Dean Goodman27-Dec-02 9:00

Dean Goodman

27-Dec-02 9:00

I've searched all over (CodeProject and the Internet at large) and I have not been able to find the answer to my problem, so here goes.

I have an MDI app where I would like to be able to open a document and immediately present the user with multiple views of the same document -- one will be the primary view, and I'd like to have two secondary views. I know that the CDocument class has a member function called AddView(), but I don't know where to add my secondary views. Where would I add my other views -- in MainFrm, ChildFrm, or elsewhere? And would using the AddView() member function be the appropriate way of accomplishing what I'm trying to do?

Thanks,

Dean

Re: MDI: Single Doc, Multiple Views

C^hris L^osinger27-Dec-02 10:25

C^hris L^osinger

27-Dec-02 10:25

take a look at: http://www.codeguru.com/doc_view/index.shtml. there are multiple articles there that show how to do multiple views on a single doc.

-c

I'm not the droid you're looking for.

ThumbNailer

CIPAddressCtrl example

ns27-Dec-02 8:18

27-Dec-02 8:18

I know how to do a .Create() and make one, but what does one do after retrieving the address the
user enters? WHich control will accept this address and open the webpage it points to? Is there a sample that shows how the addressctrl communicates this info to the ctrl that actually opens the webpage (which also I need to know about)
Thanks

Appreciate your help,
ns

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