C / C++ / MFC

1-Mar-09 10:06

If it's the same as the sample I just created, you specify the menu in the window class:

ATOM MyRegisterClass(HINSTANCE hInstance)
{
	WNDCLASSEX wcex;

	wcex.cbSize = sizeof(WNDCLASSEX);

	wcex.style			= CS_HREDRAW | CS_VREDRAW;
	wcex.lpfnWndProc	= WndProc;
	wcex.cbClsExtra		= 0;
	wcex.cbWndExtra		= 0;
	wcex.hInstance		= hInstance;
	wcex.hIcon			= LoadIcon(hInstance, MAKEINTRESOURCE(IDI_XX));
	wcex.hCursor		= LoadCursor(NULL, IDC_ARROW);
	wcex.hbrBackground	= (HBRUSH)(COLOR_WINDOW+1);
	wcex.lpszMenuName	= MAKEINTRESOURCE(IDC_XX);
	wcex.lpszClassName	= szWindowClass;
	wcex.hIconSm		= LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

	return RegisterClassEx(&wcex);
}

To get the menu for a window of this class, use GetMenu[^] using the window handle.

[edit]Here's a sample commnd handler (insert in a switch statement like the one you have in your post) that inverts the checked state for a menu item (ID_FILE_TESTITEM) when the menu item is selected. This does assume that the File menu is the first sub-menu on the menu bar.

case ID_FILE_TESTITEM:
   {
      HMENU menu = GetMenu(hWnd);
      menu = GetSubMenu(menu, 0);
      const bool checked = (GetMenuState(menu, ID_FILE_TESTITEM, MF_BYCOMMAND)&MF_CHECKED)==MF_CHECKED;
      CheckMenuItem(menu, ID_FILE_TESTITEM, MF_BYCOMMAND | (checked?MF_UNCHECKED:MF_CHECKED));
   }

[/edit]

PS - any reason you're using raw C/C++ rather than a framework (WTL or MFC)? They do make it easier to do all this, honest Smile | :)

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

modified on Sunday, March 1, 2009 4:25 PM

Mats Selen1-Mar-09 10:47

Mats Selen

1-Mar-09 10:47

Thanks!! That worked and was just what I needed!

As to why I'm doing it this way - I basically don't know any better. I am rather new to windows programming (lets just say that I learned FORTRAN using punch cards). The application I am writing is controlling some hardware so until today I was more focused on just getting the code to talk to serial ports and didn't want to try learning anything else at the same time. As long as we are on that topic, though, can you recommend a good book (or other resource) for someone starting out with MFC or WTL - something with decent examples that an old fart used to programming in vanilla C can understand Smile | :)

Stuart Dootson1-Mar-09 11:29

1-Mar-09 11:29

Mats Selen wrote:
As to why I'm doing it this way - I basically don't know any better. I am rather new to windows programming

Fair enough

Mats Selen wrote:
can you recommend a good book (or other resource) for someone starting out with MFC or WTL - something with decent examples that an old fart used to programming in vanilla C can understand

For WTL - Michael Dunn's article series on this site[^] is good.

For MFC - mmmmm, not sure. I started MFC programming over 10 years ago, when there were still MFC books around. I think it was an earlier version of this book[^]. If you have a Safari[^] subscription, that's on there.

Apart from that, best I can suggest is Google and possibly this[^]?

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Richard Andrew x641-Mar-09 13:22

Richard Andrew x64

1-Mar-09 13:22

Programming Windows with MFC - Second Edition
by Jeff Prosise

http://www.amazon.com/Programming-Windows-Second-Jeff-Prosise/dp/1572316950/[^]

template and vector [modified]

Mats Selen2-Mar-09 1:40

Mats Selen

2-Mar-09 1:40

Thanks - you guys make this a great forum!

transoft1-Mar-09 7:24

1-Mar-09 7:24

Hi

I want to use vector to save following struct. It it possible?

template <class t="">
struct Cell
{
T Val;
};

vector <<cell>> vname ?????

What is the best solution for it?

Thanks,

modified on Sunday, March 1, 2009 1:49 PM

Code-o-mat1-Mar-09 7:59

1-Mar-09 7:59

For example:

template <typename T>
struct Cell
{
  T Val;
};
#define CELL_TEMPLATE(type)   Cell<type>
std::vector<CELL_TEMPLATE(int)> my_cell_vector;

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

transoft1-Mar-09 8:14

1-Mar-09 8:14

Thank you very much for your reply. I want to use one vector to save different data type of data. How can I do it?

Best,

Code-o-mat1-Mar-09 8:18

1-Mar-09 8:18

What exactly do you mean by "save"?

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

transoft1-Mar-09 8:22

1-Mar-09 8:22

like following:

Cell<int> typeint;
typeint.Val = 1;
recVec.push_back (typeint);

Cell<float> typefloat;
typefloat.Val = (float) 1.111;
recVec.push_back (typefloat);

Code-o-mat1-Mar-09 8:43

1-Mar-09 8:43

Well, if the structure isn't too complex, you could simply use a union and some way to signal what type your struct is actually holding. Something like:

#define STRUCT_TYPE_FLOAT   1
#define STRUCT_TYPE_DOUBLE   2
#define STRUCT_TYPE_INT  3
...
struct Cell
{
public:
  short typeFlag;
  union {
    float   valFloat;
    double  valDouble;
    int     valInt;
    ...
  };
};
...
std::vector<Cell> my_vector; 
Cell cell_double;
cell_double.valDouble = 1.23;
cell_double.typeFlag  = STRUCT_TYPE_DOUBLE;
my_vector.push_back(cell_double);
Cell cell_int;
cell_int.valInt = 123;
cell_int.typeFlag = STRUCT_TYPE_INT;
my_vector.push_back(cell_int);
...

If it's a bit more complex than that then you should rather use pointers, something like this:

class CellBase
{
  virtual ~CellBase()
};
template<typename TType>
class Cell: public CellBase
{
  ...
};
std::vector<cellbase> my_vector;
my_vector.push_back(new Cell<int>(123));  //Don't forget to delete the Cells somewhere later...

These are far from complete implementations of anything, just "skeletons"...

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

transoft1-Mar-09 8:45

1-Mar-09 8:45

Thank you very much,

Code-o-mat1-Mar-09 9:08

1-Mar-09 9:08

Hmm, this is strange, i got a new notification of you posting something here, i click the link in the email, it brings me to this page but your message does not appear. I already got one of these once, maybe it is some caching problem, or something i don't yet know about the forums. Anyways, the email itself contains your post so here's an answer to that: in your CCellBase, make the destructor public.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

transoft1-Mar-09 9:50

1-Mar-09 9:50

I found the problem. Your solution is perfect.

Best,

Stuart Dootson1-Mar-09 9:30

Can a ellipsis (Variadic) function i.e Func(...) be exported from a DLL

1-Mar-09 9:30

One alternative to Code-o-mat's is to use a 'proper' type-safe variant class like Boost.Variant[^].

typedef boost::variant<int, float> Cell;

std::vector<Cell> cells;

cells.push_back(10);
cells.push_back(12.0);

for (int i=0;i<cells.size();++i)
{
    if ( int* pi = boost::get<int>( cells[i] ) )
        std::cout << "cells[" << i << "] = " << *pi << std::endl;
    else if ( float* pf = boost::get<float>( cells[i] ) )
        std::cout << "cells[" << i << "] = " << *pf << std::endl;
}

One design feature of the Boost.Variant is that you need to know what types you want to store when you build the program. Alternatively, you could use a Boost.Any[^], which allows you to store values of any type within it without pre-declaring them.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Ru_Coding1-Mar-09 4:06

Ru_Coding

1-Mar-09 4:06

Can a ellipsis (Variadic) function i.e Func(...) be exported from a DLL.
The function takes variable number of arguments. Can this be exported through a dll?

Re: Can a ellipsis (Variadic) function i.e Func(...) be exported from a DLL

Stuart Dootson1-Mar-09 4:50

Re: Can a ellipsis (Variadic) function i.e Func(...) be exported from a DLL

1-Mar-09 4:50

Don't see why not - the C run time DLL manages it for printf, sprintf etc which are variadic.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Ru_Coding2-Mar-09 1:04

Ru_Coding

2-Mar-09 1:04

Hi Stuart,
thanks for the reply, since standard functions are exported so the user defined must also be exported.

how to convert image into binary using C++

naveen20_51-Mar-09 3:53

naveen20_5

1-Mar-09 3:53

well i want image of any extension to be converted into binary and save it into some file. then read it back to generate image can any one help me plz

Re: how to convert image into binary using C++

Code-o-mat1-Mar-09 5:39