Re: srand(time(NULL)); in MSDN 2010 - C / C++ / MFC Discussion Boards

Re: MFC CListCtrl FindItem is not working

_Flaviu14-Jul-12 1:20

_Flaviu

14-Jul-12 1:20

I suggest you to use this[^] listcontrol, which can search in subitems (columns) too ...

modified 14-Jul-12 7:39am.

Re: MFC CListCtrl FindItem is not working

Rolf Kristensen14-Jul-12 21:41

Rolf Kristensen

14-Jul-12 21:41

You could insert the column you want to search in first, and then change the display order afterwards so it becomes the second column. Or just implement your own search method:

C++

CString token = "hello";
for(int i=0;i<GetItemCount();i++)

 CString subitemvalue=GetItemText( i , 2);
 if (subitemvalue == token)
     return i;
}

Re: MFC CListCtrl FindItem is not working

Richard MacCutchan14-Jul-12 0:17

Richard MacCutchan

14-Jul-12 0:17

What are the values held in your list control; i.e. is there one that starts with "DFC102"?

speaking as ...

'fopen_s' and 'fscanf_s'

mrby12313-Jul-12 10:38

mrby123

13-Jul-12 10:38

Hi Gurus,

Could you provide me some codes examples to use:

'fopen_s' and 'fscanf_s'.

Thanks

Re: 'fopen_s' and 'fscanf_s'

Wes Aday13-Jul-12 10:45

Wes Aday

13-Jul-12 10:45

http://msdn.microsoft.com/en-us/library/z5hh6ee9(v=VS.80).aspx[^]
http://msdn.microsoft.com/en-us/library/6ybhk9kc(v=VS.80).aspx[^]

Why is common sense not common?
Never argue with an idiot. They will drag you down to their level where they are an expert.
Sometimes it takes a lot of work to be lazy
Please stand in front of my pistol, smile and wait for the flash - JSOP 2012

Re: 'fopen_s' and 'fscanf_s'

jeron113-Jul-12 10:45

jeron1

13-Jul-12 10:45

fscanf_s[^]
and
fopen_s[^]

srand(time(NULL)); in MSDN 2010

mrby12313-Jul-12 7:04

mrby123

13-Jul-12 7:04

I got the following compile error message, for using:

srand(time(NULL));

warning C4244: 'argument' : conversion from 'time_t' to 'unsigned int', possible loss of data

Thanks

Re: srand(time(NULL)); in MSDN 2010

David Crow13-Jul-12 7:52

David Crow

13-Jul-12 7:52

It's not an error, but a warning. Try:

srand((unsigned) time(NULL));

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"Show me a community that obeys the Ten Commandments and I'll show you a less crowded prison system." - Anonymous

Re: srand(time(NULL)); in MSDN 2010

Albert Holguin13-Jul-12 8:37

Albert Holguin

13-Jul-12 8:37

As already stated, it's not an error but a warning. Compiler is simply making sure you're doing it on purpose and not by mistake, remember that casting may lead to digits being dropped and rounding (hence the warning). Cast the data to the appropriate type and the compiler won't warn you about it anymore.

How to undo drawing images in MFC.?

mbatra3111-Jul-12 22:51

mbatra31

11-Jul-12 22:51

Hi,

I want to provide undo/redo drawing feature in MFC dialog based application. I am saving the images dynamically in a vector in OnMouseMove handler code. But when I am going to load the previous image on clicking Undo button, its getting distorted. the last image saved still remains there on the canvas. Can anybody tell me whats the issue with OnMouseMove handler. How the compiler will know when to end saving the image.?

Regards,

Re: How to undo drawing images in MFC.?

Richard MacCutchan11-Jul-12 23:23

Richard MacCutchan

11-Jul-12 23:23

mbatra31 wrote:
How the compiler will know when to end saving the image.?

The compiler knows nothing, it's your code that has to do the work. Without seeing some of your code it's impossible to know what is going on.

speaking as ...

Re: How to undo drawing images in MFC.?

Maximilien12-Jul-12 1:15

Maximilien

12-Jul-12 1:15

Don't save the image the "OnMouseMove" event handler, save it in the OnLButtonUp handler (normally when the action is finished); or else you will end up with thousands and thousands of images.

How are you saving and putting back the image ? BitBlt ? StretchBlt ? show us some code.
If the image is stretched, are you certain you are using the good Width and Height for the bitmap ?

Watched code never compiles.

Re: How to undo drawing images in MFC.?

mbatra3112-Jul-12 3:09

mbatra31

12-Jul-12 3:09

Hi Maximilien,

Thanx for your response.
I have done that part. I am saving the images in OnLButtonUp event handler only.

Thanx & Regards,

Re: How to undo drawing images in MFC.?

Sunil P V14-Jul-12 22:09

Sunil P V

14-Jul-12 22:09

Check this link http://www.codeproject.com/Messages/4305065/Re-How-to-Undo-Redo-drawing-operation-in-a-dialog-.aspx[^]

Sunil

Querying on existing recordsets

SelvaKr11-Jul-12 21:20

SelvaKr

11-Jul-12 21:20

Hi
My application is in C++/ATL/COM and uses the Access database for storing configurations. Various DLLs and EXEs (and threads) that are part of my application query the database when needed.
When doing so, I am getting the database locked message ('[Microsoft][ODBC Microsoft Access Driver] The database has been placed in a state by an unknown user that prevents it from being opened or locked' in the log) randomly and the application fails to continue.
I am assuming that this problem happens due to the shared access of the database.

My question is:
Can i get the complete database in memory (in form of recordsets for every table) during the launch and query the recordsets directly instead of querying the database? I believe this might solve the database locking problem.

Any help is appreciated.

Thanks
Selva

Selva

Re: Querying on existing recordsets

Jochen Arndt11-Jul-12 21:45

Jochen Arndt

11-Jul-12 21:45

A better solution would be to locate and fix the problems.

Some hints:

Open database read only when no data should be written
When opening/accessing and the database is locked, retry operation after some time
When writing to the database, lock the thread so that other threads are blocked
When writing, close the database aftwerwards to avoid locking states

Re: Querying on existing recordsets

SelvaKr11-Jul-12 23:04

SelvaKr

11-Jul-12 23:04

Hi Jochen

Thanks for your response.

I am already reviewing the code and doing that. But still it fails at times. So I was thinking whether i could keep them all in memory so that the DB hits can be avoided.

Please share your thoughts.

Thanks
Selva

Selva

Re: Querying on existing recordsets

Jochen Arndt11-Jul-12 23:24

Jochen Arndt

11-Jul-12 23:24

If you have it in memory, you won't get changings. And if you add code to support changings during runtime, you may not need a database.

Assuming that all modules must then use only one function to access the memory db, why not implement the only function using direct db access?

In both cases, that function must be thread safe using locking. I think that's your problem: You access the db from different threads which may fail when the db is locked by another thread. You will have similar problems when using a memory image that is modified when not using locking (but without getting an error message).

visual c++ mfc--adding control inside list control

yasardiwan11-Jul-12 19:14

yasardiwan

11-Jul-12 19:14

i need an urgent help on this plz explain it cleraly how we can add a picture control or any other control inside list control mfc ,,,reply me as soon as possible

Re: visual c++ mfc--adding control inside list control

Richard MacCutchan11-Jul-12 23:21

Richard MacCutchan

11-Jul-12 23:21

See here[^].

speaking as ...

Re: visual c++ mfc--adding control inside list control

Albert Holguin12-Jul-12 11:09

Albert Holguin

12-Jul-12 11:09

Stop reposting the same thing...
1st post[^]
2nd post[^]

Re: visual c++ mfc--adding control inside list control

_Flaviu12-Jul-12 19:21

_Flaviu

12-Jul-12 19:21

If you want to put a background picture on a listcontrol, look here[^] and if you want to insert any kinf of control (COleDateTime, CComboBox, CEdit, and so on) to a listcontrol look here[^].

need help with serial communications

Luis Aberto Rodriguez11-Jul-12 13:29

Luis Aberto Rodriguez

11-Jul-12 13:29

hi, i'm developing an application for a school project in wich i need to read the data that an open port is about to send to another.

is there any way that i can do that?
i have search in everywhere and it seems to be no answer for that.

can anyone help me?

thanks

Re: need help with serial communications

Jochen Arndt11-Jul-12 21:37

Jochen Arndt

11-Jul-12 21:37

A serial port can be opened only by one application/thread at time. So there is no chance to do this in a simple way.

You may use some hardware that splits the serial lines and mirrors it to another port where you get a copy of the data that has been send.

You may create a special send thread that copies the data to a buffer before sending and flushes the buffer after they has been sent. You can then query the unsend data from this thread.

Re: need help with serial communications

CPallini11-Jul-12 22:21

CPallini

11-Jul-12 22:21

I suppose you should hook the WriteFile function. Not an easy task, anyway.

Veni, vidi, vici.

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