C / C++ / MFC

Re: Change collapse/expand icons in treeview

15-Aug-10 2:15

You can change the icons alongside the + ans - signs with the TreeView_SetImageList[^] command.

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Message Removed

15-Aug-10 9:33

Jamie Kenyon

15-Aug-10 9:33

Message Removed

Richard MacCutchan15-Aug-10 21:25

Re: Change collapse/expand icons in treeview

15-Aug-10 21:25

I'm not sure on this as I have only used the TVSIL_NORMAL image list. I would suggest you give it a try and see what happens.

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Matt U.15-Aug-10 4:23

Matt U.

15-Aug-10 4:23

If you mean you wish to replace the + and - images themselves then I believe you would need to draw the tree yourself, using custom draw.

http://www.google.com/search?q=C%2B%2B+MFC+Custom+Draw+Tree[^]

Diff bw BOOL and bool??

AmbiguousName14-Aug-10 22:56

AmbiguousName

14-Aug-10 22:56

hello guys...I know what is bool but what is the difference between BOOL and bool. Some other examples are TRUE and true, FALSE and false, LONG and long. Why do we need such key words in capitals.

Richard MacCutchan15-Aug-10 0:50

15-Aug-10 0:50

The ones in capitals are a throwback to the early days before these types were part of the language. They were added to the C headers to improve readability of programs.

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bleedingfingers15-Aug-10 2:59

bleedingfingers

15-Aug-10 2:59

The one in small case is C/C++ native data type that is one byte long and is used to store boolean values. The one in caps is M$ typedef'd variable. It is (usually ?) same as int or long which of course range in sizes from 2 to 4 bytes.

I personally use caps bool only to confirm to MFC/Win32 APIs and I use the native one everywhere else.

...byte till it megahertz...

Aescleal15-Aug-10 7:41

Aescleal

15-Aug-10 7:41

What keywords are those? BOOL, LONG, TRUE and FALSE aren't keywords in C or C++?

I'd assume the ones you're talking about are a part of a Microsoft operating system interface (either typedeffed or defined) and are there to aid portability and/or get over particular problems with specific compilers.

Cheers,

Ash

Eugen Podsypalnikov16-Aug-10 0:33

Eugen Podsypalnikov

16-Aug-10 0:33

The BOOL type is a redefinition of int
where FALSE is a int value of 0
and TRUE is a int value of 1...

...so you could define for example your own int UNDEFINED with value of -1
and pass it to a BOOL variable without any warning Smile | :)

The bool type is a "real bool" of MS VC++,
its variables take only the values true or false, 1 or 0 without warnings Smile | :)

The pairs long/LONG, char/CHAR, etc - are the direct redefinitions (but not bool/BOOL) Smile | :)

virtual void BeHappy() = 0;

Minimize dialog to taskbar

KarstenK16-Aug-10 2:59

KarstenK

16-Aug-10 2:59

the big onte are macros (per #define) declared types, the ones with small caps are parts of the languaage.

Press F1 for help or google it.
Greetings from Germany

john563214-Aug-10 21:27

john5632

14-Aug-10 21:27

Hi,
How to minimize a dialog in taskbar.
i tried like ShowWindow(WS_MINIMIZE); but not working...

Garth J Lancaster14-Aug-10 21:37

Garth J Lancaster

14-Aug-10 21:37

this might help

Adding Icons to the System Tray[^]

john563214-Aug-10 21:46

john5632

14-Aug-10 21:46

not is system tray, I want to make it minimize in taskbar.

Richard MacCutchan15-Aug-10 0:58

Re: Minimize dialog to taskbar [modified]

15-Aug-10 0:58

john5632 wrote:
i tried like ShowWindow(WS_MINIMIZE); but not working.

It should be ShowWindow(SW_MINIMIZE); - WS_ values are windows styles, SW_ values are ShowWindow() command parameters.

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Eugen Podsypalnikov15-Aug-10 10:12

Eugen Podsypalnikov

15-Aug-10 10:12

I would apply just the following to the words of Richard:
there are two - known for me - reasons for "a dialog" to be minimized:
- the dialog is modeless (could be a child of the desktop Smile | :)

)
- the dialog is the application window (the style WS_EX_APPWINDOW could be applied in OnInitDialog() Smile | :)

)

An emulation of the second reason:

int CYourDialog::OnInitDialog()
{
  int iResult = CDialog::OnInitDialog();

  // Adding of the APP-style...
  LONG lStyle = GetWindowLong(GetSafeHwnd(), GWL_EXSTYLE) | WS_EX_APPWINDOW;
  SetWindowLong(GetSafeHwnd(), GWL_EXSTYLE, lStyle);
  // Now the dialog should be ready to be minimized...
  // CAUTION: the parent window stays disabled,
  // if the dialog is not modeless... :)

  //...

  return iResult;
}

virtual void BeHappy() = 0;

modified on Monday, August 16, 2010 3:48 AM

Richard MacCutchan15-Aug-10 21:31

ofstream can't write a "double" value into a file correctly

15-Aug-10 21:31

Eugen Podsypalnikov wrote:
there are two - known for me - reasons for "a dialog" to be minimized

Thanks, I couldn't think of one; but, hey, the customer wants it, the customer can have it. Wink | ;)

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Joseph Marzbani14-Aug-10 19:19

Re: ofstream can't write a "double" value into a file correctly

14-Aug-10 19:19

I've a structure like this:

struct STRUCT<br />
{<br />
bool b;<br />
int i;<br />
double d;<br />
}str;<br />
// initializing<br />
str.b = true;<br />
str.i = 18;<br />
str.d = 20<br />

and because I know I can't get the real size of a structure using operator sizeof, I write it into a file in this way:

wofstream of("FileName.dat", ios:out 
of.write(reinterprete_cast <char*> (&str.b), sizeof(bool));
of.write(reinterprete_cast &lt;char*&gt; (&str.i), sizeof(int));
of.write(reinterprete_cast &lt;char*&gt; (&str.d), sizeof(double));

and finally when I read it again into "str" and display it using cout, I got this values:

str.b = true;
str.i = 18;
str.d = 20.001

why 20.001 instead of 20 is written? I took a look into the file using a HEX-Editor and I saw 20.001!!!

Garth J Lancaster14-Aug-10 20:07

Garth J Lancaster

14-Aug-10 20:07

its not a problem with ofstream - its a problem with your understanding of how floating point numbers are handled by computers - I suggest you start reading here for example : http://www.johndcook.com/blog/2009/04/06/anatomy-of-a-floating-point-number/[^]

'g'

Re: ofstream can't write a "double" value into a file correctly

Joseph Marzbani14-Aug-10 20:49

Re: ofstream can't write a "double" value into a file correctly

14-Aug-10 20:49

Thank you! but one expects to get whatever he's saved on a file as the original value. I'll read that article for sure. but for now could you explain what should I do to save and retrive a "double" value. a short exam will be appreciated.

Garth J Lancaster14-Aug-10 21:19

Garth J Lancaster

14-Aug-10 21:19

that article explains why you are seeing that value - what you are seeing is 20 +/- epsilon, written out with the precision you specified (or rather in this case, didnt specify)

you need to look at using <iomanip> and the precision specifier at least

so google iomanip and precision

'g'

Re: ofstream can't write a "double" value into a file correctly

Joseph Marzbani14-Aug-10 22:34

Re: ofstream can't write a "double" value into a file correctly

14-Aug-10 22:34

thank you! It was really helpful

Aescleal14-Aug-10 22:01

Aescleal

14-Aug-10 22:01

Firstly - of course you can get the size of a structure using sizeof - that's what it's there for. It's only when you make some crass assumptions about what sizeof does that you get into trouble.

Secondly are you sure the code you've presented to us, HTML foobars aside, is the code you've been using? The reason I ask is that a standard conforming compiler won't accept the line:

of.write(reinterpret_cast <char*> (&str.b), sizeof(bool));

as the first parameter to std::basic_stream<char_type>::write is char_type * or wchar_t * for a wofstream. So the first thing I'd do is grab a standard comforming C++ compiler and give your code another go.

Cheers,

Ash

Re: ofstream can't write a "double" value into a file correctly

Joseph Marzbani14-Aug-10 22:40