C / C++ / MFC Discussion Boards

Re: Icon on Pushbuttons

Monty²28-Dec-03 20:34

Monty²

28-Dec-03 20:34

Here is a link to an article on codeproject might come in handy Smile | :)

Click ME[^]

Live as if your were to die tomorrow. Learn as if you were to live forever.
-Mahatma Gandhi

Re: Icon on Pushbuttons

David Crow29-Dec-03 5:19

David Crow

29-Dec-03 5:19

Here's another article:

http://www.flounder.com/bitmapbutton.htm

A rich person is not the one who has the most, but the one that needs the least.

Complementary text color

Mihaly Zsadanyi28-Dec-03 16:35

Mihaly Zsadanyi

28-Dec-03 16:35

Does anyone know of an algorithm to calculate a complementary text color given a background color? By this I mean a text color so that the text can easily be read. I've scoured the Web but have not come up with anything useful.

I have low vision, and have difficulty reading the text on some of the controls being developed in my company where the text and background color don't contrast enough. If colors are hard-coded, there will always be some color scheme for which this will not work.

Any suggestions will be much appreciated.

Mihaly Zsadanyi

Re: Complementary text color

PJ Arends28-Dec-03 16:53

PJ Arends

28-Dec-03 16:53

IMO all controls should use the system colours for their backgounds and text, that way the user can choose whatever colour they are most comfortable with. Use COLOR_WINDOW or COLOR_3DFACE for backgrounds, and COLOR_WINDOWTEXT or COLOR_BTNTEXT for foregrounds. Any other combinations may look cool, but are disrepectful of the end user.

Sonork 100.11743 Chicken Little

"You're obviously a superstar." - Christian Graus about me - 12 Feb '03

Within you lies the power for good - Use it!

automatic reading .txt file

cowenchin28-Dec-03 16:34

cowenchin

28-Dec-03 16:34

I'm using Visual C++ to program an application that reading from a .txt file at some time interval, let's say 10 seconds.How can i do this? Please help me. Thank you. Big Grin | :-D

Re: automatic reading .txt file

Monty²28-Dec-03 20:42

Monty²

28-Dec-03 20:42

You have to Set a timer via . SetTimer function
then in the Timeout Handler Read the txt file (use CFile)

if you have a Dialog based Application

then in OnInitDialog 
SetTimer(1,10000,NULL);

add handler for WM_TIMER event (via Class Wizard)

..... OnTimer(UINT nIDEvent)
{
//do the file opening stuff
}

Live as if your were to die tomorrow. Learn as if you were to live forever.
-Mahatma Gandhi

USB interface

siew hoon28-Dec-03 15:59

siew hoon

28-Dec-03 15:59

Hi,

I need to use USB to interface between a hardware and PC. What command/tool should I use? Any sample code? Blush | :O

Re: USB interface

benben28-Dec-03 21:49

benben

28-Dec-03 21:49

I don't realy know USB,but I think the hardware should provide that tool or the driver lib.

Thanks
Benben

What is the difference between CClientDC and CDC?

siew hoon28-Dec-03 15:57

siew hoon

28-Dec-03 15:57

Hi,

What is the difference between using CClientDC to draw graph and using CDC? D'Oh! | :doh:

Re: What is the difference between CClientDC and CDC?

PJ Arends28-Dec-03 16:46

PJ Arends

28-Dec-03 16:46

basicly nothing. The only difference is that CClientDC calls GetDC() on the supplied window in it's constructor, and calls ReleaseDC() in it's destructor. It just saves you some typing and debugging time.

Sonork 100.11743 Chicken Little

"You're obviously a superstar." - Christian Graus about me - 12 Feb '03

Within you lies the power for good - Use it!

How to permanent fix the dialog as maximize

siew hoon28-Dec-03 15:51

siew hoon

28-Dec-03 15:51

I had create a SDI with database. How do I maximize the dialog permanently?
I drawed some pictures on the dialog. When I maximize the dialog, there's a assertion error. What should I do? Confused | :confused:

Re: Updating a Progressbar while the App is doing hard work

PJ Arends28-Dec-03 15:57

PJ Arends

28-Dec-03 15:57

http://www.codeproject.com/cpp/cppforumfaq.asp#ui_workerthread[^]

Sonork 100.11743 Chicken Little

"You're obviously a superstar." - Christian Graus about me - 12 Feb '03

Within you lies the power for good - Use it!

\device\harddiskvolume1\windows\..

pranavamhari28-Dec-03 14:43

pranavamhari

28-Dec-03 14:43

hi,

I want to convert the string '\device\harddiskvolume1\windows\..' to the path 'c:\windows\..'

I get that string from the registry. I can replace the string
'\device\harddiskvolume1' to c:
'\device\harddiskvolume2' to d:
etc.
But I doubt there is a much better way using some API.

Can anyone please help ?

regards
hari

Hari Krishnan

Getting path of dll within that dll

Kuniva28-Dec-03 14:30

Kuniva

28-Dec-03 14:30

How can i get the path of my dll on disk from within that dll?? Like.. a program loads my dll as a plugin but the dll itself doesnt care where it is. Is there a way to get the path to the dll from within the dll code?

Thanks

Kuniva
--------------------------------------------

Re: Getting path of dll within that dll

Garth J Lancaster28-Dec-03 15:07

Garth J Lancaster

28-Dec-03 15:07

Kuniva wrote:
but the dll itself doesnt care where it is

I wouldnt say that was 'accurate' .. there's a set path windows uses to locate dll's .. from memory, its (very roughly), assuming NT for the moment

1) The directory the calling exe was loaded from
2) C:\winnt
3) C:\winnt\system32
4) The Contents of the PATH Environment variable

so the dll has to be 'somewhere useful' .... so you could use the file find functions ... checking that the above list was accurate, of course ...

As far as I recall, the info isnt stored 'within' a dll... The only other way may be to enumerate processes and maybe the process stack shows where it was loaded from - www.sysinternals.com has some tools that may demonstrate this .. but thats way complex !!!

Most 'plugin' factories to use a better word should have a configurable parameter that says, 'my plugins are in here' and not assume they are anywhere, imho ..

hth

Re: Getting path of dll within that dll

PJ Arends28-Dec-03 15:08

PJ Arends

28-Dec-03 15:08

A guess:

Try GetModuleFileName() passing in the instance handle of the dll. The handle is the first parameter passed into your DllMain() function, or it can be retrieved using the AfxGetInstanceHandle() function if you are using MFC and your dll was linked with the USRDLL version of MFC.

Sonork 100.11743 Chicken Little

"You're obviously a superstar." - Christian Graus about me - 12 Feb '03

Within you lies the power for good - Use it!

Problem with double

User 58385228-Dec-03 13:47

User 583852

28-Dec-03 13:47

Hello,
I have the following simple code and I cant understand the results I am seeing

Note. This is a big hack in an old peice of code. It would not be like this if I had my way Frown | :(

void SomeFn(void)
{
//these are not hard coded they come from another API in string form
CString result = CalcMargin("0.7033", "0.7000");
}

CString CalcMargin(LPCTSTR exeRate, LPCTSTR rate)
{
double dExeRate, dRate, dMargin;

dExeRate = atof(exeRate);
dRate = atof(rate);

dMargin = dExeRate - dRate;

result.Format("%f", dMargin);

return result;
}

The returned value is "0.003300" and I wondered why i see the trailing zeros. It turnes out that the result of the subtraction is 0.0033000000000001

Can anyone tell me why?
Thanks

Re: Problem with double

kjessee28-Dec-03 14:04

kjessee

28-Dec-03 14:04

Try this

result.Format("%5.4lf", dMargin);

where 5 is the minimum width and 4 is the precision.
the lf is for double values.

Re: Problem with double

Michael Dunn28-Dec-03 17:58

Michael Dunn

28-Dec-03 17:58

Rounding error.
Floating-point numbers cannot be stored as the exact equivalent of their decimal representation, unless they all happen to be powers of two (2, 4, .125, etc.). So you should never check for strict equality when dealing with float/double values.

--Mike--
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Re: Problem with double

User 58385228-Dec-03 18:12

User 583852

28-Dec-03 18:12

Thanks but im not sure I understand completely. Would you expect "true" or "false" from the following code? It prints true when i run it.

double d1 = 5; //not a power of 2
double d2 = 2;

if( (d2 * 5.0 / 2.0) == d1)
printf("true");
else
printf("false");

Re: Problem with double

PJ Arends28-Dec-03 18:43

PJ Arends

28-Dec-03 18:43

You are using whole numbers. Try with fractions

double d1 = 1;
double d2 = 3;
double d3 = d1 / d2;
if (d3 == 0.333) // what number to use?
   printf ("true");
else
   printf ("false);

No matter what number you use, you will never get true.

Sonork 100.11743 Chicken Little

"You're obviously a superstar." - Christian Graus about me - 12 Feb '03

Within you lies the power for good - Use it!

Re: Problem with double

User 58385229-Dec-03 17:57

User 583852

29-Dec-03 17:57

cheers!

Need help with ODBC database/Edit box

Zombie_Inc28-Dec-03 12:15

Zombie_Inc

28-Dec-03 12:15

Hi there,

I'm relatively new to the C++ language. Recently I started with a database application in Visual C++6.

Here is my question:

After loading a couple of (lest's say four) Edit boxes from an MS Access database through the MFC ODBC, I would like to calculate the value of some of the boxes and have the sum in a fifth Edit box.
The database consist of both integer and floating numbers.

I use the GetFieldValue to copy database values into a variable using the CString class.

How do I get the variables recognized as numbers?
This is easy to do in VB6 but how is it done in Visual C++6. There must be a way!

I would really appreciate all the help I can get.
Thanks in advance
Lars

Re: Need help with ODBC database/Edit box

PJ Arends28-Dec-03 15:24

PJ Arends

28-Dec-03 15:24

atof()<br />
atoi()<br />
_atoi64()<br />
atol()<br />
atold()<br />
strtod()<br />
StrToInt()<br />
StrToIntEx()<br />
strtol()<br />
strtoul()

Take your pick

Sonork 100.11743 Chicken Little

"You're obviously a superstar." - Christian Graus about me - 12 Feb '03

Within you lies the power for good - Use it!

Simple Problem. How can I show an "Open file" dialog in a dialog-based App from MFC AppWizard

andreir2328-Dec-03 12:07

andreir23

28-Dec-03 12:07

I am a Visual C++ newbie (I worked with Borland Delphi a long time so I know something... although not what I need now).

I have to write a file encoder. In VC++ 6
Everything is set, I began a new project with MFC AppWizard, I selected dialog-based and now I have a dilemma:

How do I show up an "Open file" dialog type window??! and a save one too...
I would like if possible to be able to change the file filter and/or caption (I am developping it in another language)

Like in Notepad when you hit CTRL-O or File->Open. I don't necesarily need it Win2000/XP style but I HOPE THERE IS A FUNCTION IN THE WIN SDK.

In delphi it was so simple.Just drop a OpenFileDialog control on the main form and say: "Dialog1.Execute();"
Visual C++ is certainly no RAD for me...

Thanks in advance! Wink | ;-)

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