a tyro's question - C / C++ / MFC Discussion Boards

Re: GDI resource leak with MFC apps on XP SP2

Gary R. Wheeler19-Sep-04 15:38

Gary R. Wheeler

19-Sep-04 15:38

Clickety[^]

Software Zen: delete this;

Random numbers

Cedric Moonen16-Sep-04 22:46

Cedric Moonen

16-Sep-04 22:46

Hello !
I would like to produce random numbers between 0 and 15. I tried to use srand and rand. So I used a similar code:

#define RAND_MAX  15     //Outside of the function<br />
srand(1);<br />
int Random = rand();<br />

But the numbers are greater than 15 Confused | :confused:

How can I do that ?
Thanks

Re: Random numbers

Mike Beckerleg16-Sep-04 22:59

Mike Beckerleg

16-Sep-04 22:59

Just #defining your own RAND_MAX is no good. The rand() method uses the RAND_MAX that was defined when the library it was in was compiled. To get it into a particular range try something like:

int Random = rand()*(15/RAND_MAX);

The other thing to note is that if you always seed the random number generator with the same number (1 in your example), it will always generate the same sequence of pseudorandom numbers. Try something like:

srand( (unsigned)time( NULL ) );<br />

This seends the generator with a value based on the current time so it should give you different sequences.

Mike

Re: Random numbers

Cedric Moonen16-Sep-04 23:02

Cedric Moonen

16-Sep-04 23:02

Thanks

Re: Random numbers

Martijn van Kleef16-Sep-04 23:58

Martijn van Kleef

16-Sep-04 23:58

To produce random numbers from 0 to some predefined limit it would probably be easiest to do:
#define RAND_MAX_LIMIT 15 // Set 15 as limit for randomly generated values
srand((unsigned)time(NULL)); // Seed random number generator with current time
int Random = rand() % (RAND_MAX_LIMIT + 1); // Only generate numbers between 0 and your predefined limit

Re: Random numbers

David Crow17-Sep-04 9:35

David Crow

17-Sep-04 9:35

cedric moonen wrote:
I would like to produce random numbers between 0 and 15.

Try rand() % 16.

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

Hyperlink(Button)List ??

Hardy_Smith16-Sep-04 22:20

Hardy_Smith

16-Sep-04 22:20

Hi Folks,

I am searching a listbox similar to the "favorits" list in IE6. A List with buttons or hyperlinks whitch I can dynamically add and remove. I need it for a MFC-App.

Sorry, don`t have time to write it myselfe...

Anybody knows something??

Thanks, Hardy.

a tyro's question

pcbirdwang16-Sep-04 22:08

pcbirdwang

16-Sep-04 22:08

How can I transmit a xml's datas to multi-listview？TKS！give me some sourcecodes pls.tks!

Using SetTimer

GDavy16-Sep-04 21:06

GDavy

16-Sep-04 21:06

Hello,
Quick question...
I have CDialog derived dialog and in it I start a timer in the OnInitDialog with a specific ID. I never kill that timer though when leaving the dialog.
Does anybody know if this might build up resources calling the SetTimer multiple times(with same ID!!!) without specifically killing it ever.
Does the Timer get killed when the dialog object goes out of scope?

Thx for any light on this subject..

Greetz,
Davy

Re: Using SetTimer

Mike Beckerleg17-Sep-04 1:28

Mike Beckerleg

17-Sep-04 1:28

I believe calling SetTimer multiple times will create multiple system timers, even if you call it with the same ID. The id is the value the timer returns to you when it ticks. This is different to the timer identifier which is the value returned by SetTimer.

The timer will not get killed when the dialog goes out of scope, you need to call KillTimer with the value returned by SetTime.

Mike

Re: Using SetTimer

David Crow17-Sep-04 9:37

David Crow

17-Sep-04 9:37

Timers are a limited system-wide resource, meaning that they can run out.

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

SuspendThread & TerminateThread

Martijn van Kleef16-Sep-04 21:02

Martijn van Kleef

16-Sep-04 21:02

I find the VS help to be a little vague on this method, does SuspendThread halt execution of a thread -immediately-? And what if the thread contains some no-user-mode code? Can I use it to decently halt a thread before calling TerminateThread to brutally kill it?

PS: I'm using TerminateThread because in one of my threads I'm calling into a function of a third-party lib (out of my control) that sometimes hangs. TerminateThread seems the only option left to stop the hanging (now threaded) function and retain control over application execution.

Re: SuspendThread & TerminateThread

Neville Franks17-Sep-04 0:36

Neville Franks

17-Sep-04 0:36

I don't know the answer to SuspendThread but I technique I find interesting and usefull to kill a thread is to force it to thow an exception. Have a look at http://www.codeproject.com/threads/threadlibrary.asp[^] which uses this technique.

Hope that helps.

Neville Franks, Author of ED for Windows www.getsoft.com and coming soon: Surfulater www.surfulater.com

CListCtrl-Multi-selection using SHIFT & arrow Key

krishnakumar7516-Sep-04 20:49

krishnakumar75

16-Sep-04 20:49

Hi,
I am working with CListCtrl in VC++ where I tried to implemnt the multi-selection of Items by
1) SHIFT+ Mouse click
2) SHIFT+ Arrow Key selection

I could implement these with NM_CLICK and ITEMCHANGED respectivly,
but gives inconsistant selected items.

Plse anybdy to solve this situation by tech advice/code snippet

Thanks,

Krishna

Krishnakumar

Re: CListCtrl-Multi-selection using SHIFT & arrow Key

Chris Richardson18-Sep-04 21:55

Chris Richardson

18-Sep-04 21:55

If the default multi selection works for you, then just turn off the single selection style:

m_YourListControl.ModifyStyle( LVS_SINGLESEL, 0 );

If that's not what you're after, sorry.

Chris Richardson

Re: CListCtrl-Multi-selection using SHIFT & arrow Key

krishnakumar7520-Sep-04 18:05

krishnakumar75

20-Sep-04 18:05

Hi, Thanks for reply.But I need the ListCtrl as multi-selection and I made it multiselection type.
It visually selects the multiple items too. But the problem is that when I tried to delete these items the count is inconsistant.

Krishna

Krishnakumar

Error in ATL ( COM) DLL ???

zahid_ash16-Sep-04 20:03

zahid_ash

16-Sep-04 20:03

m makeing ATL DLL using ATL COM Wizard

i m getting an error as follows

F:\rough work\atl2\atl2.idl(18) : error MIDL2025 : syntax error : expecting a type specification near "CString"

for the line given below

[id(1), helpstring("method Connect")] HRESULT Connect(CString ip , int port);

how can i remove the eror

thanx

Regards.

Visual C++ (MFC) : Using Matrix to set an part of an image to zero

pohcb_sonic16-Sep-04 16:07

pohcb_sonic

16-Sep-04 16:07

I actually had previously used it to do console applications on Visual C++ but never used MFC before. I had a problem; I was told to set a 4 by 4 area by using Matrix in MFC coding and use it to check whether the image has any little "black spots". If it does, I have to set these small little "black spots" of the image from "255" or anything else to zero. The codings must be in a function.

So How do I do it?

Pls do kindly reply. I needed this asap. Thanks!

Below are the codes: (the codes have quite a bit of a problem...)

<br />
void CMediVisionView::MatrixImage()<br />
{<br />
int i;<br />
<br />
if(no_of_rows==512){<br />
for(i=0; i<512-5; i++)<br />
{<br />
if (image512[i]==0 && image512[i+1]==0 && image512[i+2]==0 && image512[i+3]==0 && image512[i+4]==0){<br />
<br />
if(image512[i]==0 && image512[i+512]==0 && image512[i+(512*2)]==0 && image512[i+(512*3)]==0){<br />
<br />
if(image512[i+4]==0 && image512[i+512+4]==0 && image512[i+(512*2)+4]==0 && image512[i+(512*3)+4]==0){<br />
<br />
if(image512[i+(512*3)+1]==0 && image512[i+(512*3)+2]==0 && image512[i+(512*3)+3]==0 && image512[i+(512*3)+4]==0){<br />
<br />
image512[i+512+1]=0;<br />
image512[i+(512*2)+1]=0;<br />
image512[i+(512*3)+1]=0;<br />
<br />
image512[i+512+2]=0;<br />
image512[i+(512*2)+2]=0;<br />
image512[i+(512*3)+2]=0;<br />
<br />
image512[i+512+3]=0;<br />
image512[i+(512*2)+3]=0;<br />
image512[i+(512*3)+3]=0;<br />
}<br />
<br />
}<br />
}<br />
<br />
}<br />
<br />
}<br />
}<br />
<br />
<br />
<br />
}<br />

msflexigrid

persian_boi16-Sep-04 15:59

persian_boi

16-Sep-04 15:59

i have a msflexigrid, works great, but i am wondering how to let the user click on a cell and copy the data inside of the cell (not edit the cell, just copy the data inside of the cell) ... any ideas?

Example of IPC in VC++ .Net

hatimad16-Sep-04 12:47

hatimad

16-Sep-04 12:47

Hello all,

I have an assignment to make a board game in VC++ .Net , I am required to make GUI and create 3 processes Master, player1 and player2....

I have been looking online for IPC and have found some examples but all went over the top of my head....

I would appreciate if someone could give me an example explaining...

create process ( i.e. initialize player1 from master )
pass data ( structure ) to player1
receive feedback from player1
pass data to player2 ( it has already been initialized before i.e after player1)
receive feedback from player2
pass data to player1( what will happen to player1 in the mean time? )

Thanks a lot

Multiple Parallel Ports

wicked_guy16-Sep-04 11:58

wicked_guy

16-Sep-04 11:58

Hi Everyone,

Could anyone please give me details about controlling more than one parallel from the same CPU unit.

Thanx in advance

Re: Multiple Parallel Ports

Christian Graus16-Sep-04 15:58

Christian Graus

16-Sep-04 15:58

Each parallel port has it's own address that you scan, so the presence of any other parallel port is irrelevant. You use the address needed for the port you are scanning.

There are some good articles here on Code Project about parallel ports.

Christian

I have drunk the cool-aid and found it wan and bitter. - Chris Maunder

Re: Multiple Parallel Ports

wicked_guy16-Sep-04 21:46

wicked_guy

16-Sep-04 21:46

Thanx for the reply Christian. Could that be done with MFC as well or just Win32 Applications.

Re: Multiple Parallel Ports

Christian Graus19-Sep-04 11:04

Christian Graus

19-Sep-04 11:04

MFC is just a fat old library on top of Win32. Hell, C# is just a fat old library on top of Win32. I actually do what I've described in C# by calling the underlying libaries in the DLL's. You can do anything Win32 supports in MFC.

Christian

I have drunk the cool-aid and found it wan and bitter. - Chris Maunder

C++ code for 3D

suiram4016-Sep-04 11:18

suiram40

16-Sep-04 11:18

Check latest release of GETIC 3D that comes with C++
source code for navigating in a 3D world . Smile | :)

http://getic.njoydeco.com

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