C / C++ / MFC

Re: ifstream trouble-big trouble

11-Aug-02 0:34

You're supposed to know the format of data before you ask for it. Otherwise you should read it as std::string's. You'd use getline and specify the delimiter you've used in your files ( a , or a tab I'd guess ), then you could step over it and put default values into anything that is 0 length, and figure out which fields are numbers.

valikac11-Aug-02 6:15

valikac

11-Aug-02 6:15

The best solution is to use a data structure. You could create this data structure yourself and thus you know the exact format.

Otherwise, you could use the getline and string technique, but then you will need an algorithm to determine the integrity of each role of data in the file.

You could use isdigit() to determine the data type of each byte in the file.

Kuphryn

What exactly is a memo type field in Access?

nss10-Aug-02 23:07

10-Aug-02 23:07

In a text field you can put strings, in a number field, numbers, in an OLE Objectfield you can put binary data. In a memo field what type of data is put in? How do you retrieve it? Like for binary data we use GetChunk. So for a memo field, how do you put it in to the Access db and subsequently extract it?

Thanks,
ns

Anonymous10-Aug-02 23:24

10-Aug-02 23:24

Use the help file
to read about the difference between
text and memo
Wink | ;)

nss11-Aug-02 0:50

11-Aug-02 0:50

Is there a link to this? All the MSDN memo entries appear to be for FoxPro...
Thanks,
ns

Anonymous11-Aug-02 1:59

11-Aug-02 1:59

Use the Access-Helpfile by pressing F1
Use the index tab and type memo

nss11-Aug-02 3:24

11-Aug-02 3:24

Ah! I see. I hadnt even thought of Access help!
ns Blush | :O

Anonymous11-Aug-02 3:29

11-Aug-02 3:29

Hope it helps you
I'd posted the lines but I've
only some in german
Wink | ;)

a simple SQL question

nss10-Aug-02 23:00

Re: a simple SQL question

10-Aug-02 23:00

I know we can do stuff like

Select * from tbl where (Color = 'red') AND (Shape = 'round)

But what if we had an integer instead of a string for a value i.e.

Select * from tbl where (Color = 'red') AND (Shape = 'round)AND (Depth = 100)

Is the above legal? We dont need ' 100'? Just plain 100?

Thanks,
ns

Anonymous10-Aug-02 23:17

Re: a simple SQL question

10-Aug-02 23:17

It's legal,
but
(Shape = 'round')
instead of
(Shape = 'round)

Anonymous11-Aug-02 0:35

Re: a simple SQL question

11-Aug-02 0:35

Yes, and the results will differ. '100' will do a string comparison, so that 100 < 99, and 100 will do a numeric one, so 100 > 99.

nss11-Aug-02 3:23

menu disabling problem(urgent)

11-Aug-02 3:23

Great! Thats very good to know. Appreciate it,
ns

I wonder why my code crashes. I build the query on the fly, and one fld returns a number which I currrently put in as 'number' and not number, so in the query i have ....and (depth = '100'). This query should clear becauseit shouldnt find any such records, but instead it crashes....
Havent debugged this seriously..

SilentWarrior10-Aug-02 22:57

SilentWarrior

10-Aug-02 22:57

hi ..
im trying to control my menus from my code segment. i.e i want to disable enable them according to my needs.
the code which im writing works perfectly in the dialog based application but it aint working in my SDI application

CMenu* mmenu=GetMenu();
CMenu* submen=mmenu->GetSubMenu(0);
submen->EnableMenuItem(ID_FILE_OOP,MF_BYCOMMAND|MF_DISABLED|MF_GRAYED);

kindly tell me a way so that i can use this code for my sdi application .

thankks

looking forward from all the gurus of code

Re: menu disabling problem(urgent)

Hans Ruck11-Aug-02 4:09

Hans Ruck

11-Aug-02 4:09

Have you tried submen->EnableMenuItem(ID_FILE_OOP,MF_BYCOMMAND|MF_GRAYED);?

rechi

Re: menu disabling problem(urgent)

Mike Upton12-Aug-02 0:29

Mike Upton

12-Aug-02 0:29

The problem is that your frame window (in an SDI app created by the wizard, that'll be CMainFrame) is automatically enabling/disabling menus based on whether they have a command handler registered (if there is a command handler available, the menu item will be enabled). The reason the code worked properly in the dialog based application is that there is no frame window in a dialog app.

The best solution is almost always to use an update handler (ON_UPDATE_COMMAND_UI in the message map - look it up in MSDN if you don't know about it) to update the enabled state of your menu item. This is also mentioned in Michael Dunn's C++ FAQ (section 7.1) here at CodeProject.

If you really can't/can't be bothered to use an update handler, you can tell the frame window not to automatically enable/disable menu items - set its m_bAutoMenuEnable property to false. But the update handler method is much better!

"We are the knights who say Ni" _{(The Knights Who Say Ni)}

Color Brightness

Wolfram Steinke10-Aug-02 22:58

Wolfram Steinke

10-Aug-02 22:58

I'm looking for a simple way to increase or decrease the brightness of a specified color, for making a highlight and shadow color to match the given one.
Any idea will be muchly appreciated.

Happy programming!!

Re: Color Brightness

Anonymous11-Aug-02 0:36

Is my CString format suspect here?

11-Aug-02 0:36

Look up HLS on the net - you need to convert to HLS, increase the appropriate value, and convert back to RGB.

Re: Color Brightness

Peter Occil11-Aug-02 6:35

Peter Occil

11-Aug-02 6:35

My post at CodeGuru Forums[^] :

A simple way to adjust the brightness of a color is to adjust a constant value of red, green, and blue in a color. Here is a function for this.

COLORREF Brighten(COLORREF cr, int val){
 BYTE r,g,b;
 r=(BYTE)min(255,max(0,GetRValue(cr)+val));
 g=(BYTE)min(255,max(0,GetGValue(cr)+val));
 b=(BYTE)min(255,max(0,GetBValue(cr)+val));
 return RGB(r,g,b);
}

A positive value for val brightens the color, and a negative value for val darkens the color. Be sure the val parameter is within the range -255 to 255.

Peter O.

nss10-Aug-02 19:24