C / C++ / MFC

23-Sep-04 18:00

You're missing the argument to static_cast. Btw, the code looks very suspect. Why do you have a nested if when all you really need to do (imho) is:

if ((riid == IID_IUnknown) ||
    (riid == IID_IX) ||
    (riid == IID_IY))
   *ppvObject = static_cast(this);
else {
   ppvObject = NULL;
   hr = E_NOINTERFACE;
   ...
}

/ravi

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Re: Syntax Error

Guoguor23-Sep-04 22:36

default child window size in vc++ mdi application???

23-Sep-04 22:36

I think you miss ";" at the end of the line " *ppvObject = static_cast ",do you?

free like a bird

vc-programmer-23-Sep-04 17:32

vc-programmer-

23-Sep-04 17:32

hi every body!!

i have problem that default many child window size.
i want to get that when main window appear different size many child window are default.
i want to know where this sample code.
please give me.
thank all!!!!

phoophoo2004@indiatimes.com

GetDefaultPrinter

sixiang23-Sep-04 16:57

sixiang

23-Sep-04 16:57

From MSDN, it says

GetDefaultPrinter is included in Windows 2000 or later.

I am using WIndows XP, and look at the windows.h and winspool.h, I could find the declaration of this function.

In fact I try to run the following sample code provided by MSDN at

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/gdicpp/GDIPlus/UsingGDIPlus/Printing/SendingGDIPlusOutputtoaPrinter.asp

But it failed by saying the GetDefaultPrinter undefined.

Can anyone help me to fix this problem? Becasue I would like bypass the Printer Diolog using GetDefaultPrinter.

Thanks a lot

David

//-----------------------
#include <windows.h>
#include <gdiplus.h>
#include <stdio.h>
using namespace Gdiplus;

INT main()
{
// Initialize GDI+.
GdiplusStartupInput gdiplusStartupInput;
ULONG_PTR gdiplusToken;
GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);

DWORD size;
HDC hdcPrint;

DOCINFO docInfo;
ZeroMemory(&docInfo, sizeof(docInfo));
docInfo.cbSize = sizeof(docInfo);
docInfo.lpszDocName = "GdiplusPrint";

// Get the size of the default printer name.
GetDefaultPrinter(NULL, &size);

// Allocate a buffer large enough to hold the printer name.
TCHAR* buffer = new TCHAR[size];

// Get the printer name.
if(!GetDefaultPrinter(buffer, &size))
{
printf("Failure");
}
else
{
// Get a device context for the printer.
hdcPrint = CreateDC(NULL, buffer, NULL, NULL);

StartDoc(hdcPrint, &docInfo);
Graphics* graphics;
Pen* pen = new Pen(Color(255, 0, 0, 0));

StartPage(hdcPrint);
graphics = new Graphics(hdcPrint);
graphics->DrawRectangle(pen, 50, 50, 200, 300);
delete graphics;
EndPage(hdcPrint);

StartPage(hdcPrint);
graphics = new Graphics(hdcPrint);
graphics->DrawEllipse(pen, 50, 50, 200, 300);
delete graphics;
EndPage(hdcPrint);

delete pen;
EndDoc(hdcPrint);

DeleteDC(hdcPrint);
}

delete buffer;

GdiplusShutdown(gdiplusToken);
return 0;
}

David

ie side bar want to add a tree

NotoriousBIG_PJ23-Sep-04 16:26

NotoriousBIG_PJ

23-Sep-04 16:26

I would like to put some sort of tree structure in an internet explorer side bar but I haven't been able to merge my bar with any of the many types of trees I have learned about these past couple of weeks. Something like the view->explorer bar->folders would be optimal. I hope someone can at least point me in the right direction. Smile | :)

Thanks in advance,

Biggie.

The introduction in detail !

Guoguor23-Sep-04 16:07

Re: The introduction in detail !

23-Sep-04 16:07

I use the function
int ExtEscape(
HDC hdc,
int nEscape,
int cbInput,
LPCSTR lpszInData,
in cbOutput,
LPSTR lpszOutData
);
at my program.Because of my poor English,I couldn't understand the function's introduction at Microsoft Windows CE.NET Help.Could you give me a introduction about the function and the use of it in detail?
Thanks!

free like a bird

Roger Wright23-Sep-04 20:41

Roger Wright

23-Sep-04 20:41

The documentation in the Platform SDK covers this in detail, but in brief this function allows you to access driver-specific functions that are not exposed by the Windows GDI. The specific device is passed to the function using its handle, hdc. The device driver function is specified by nEscape, while lpszInData is a pointer to whatever data is required as input for the function. The cbInput parameter specifies the size of the structure indicated by lpszInData in bytes. Similarly, the lpszOutData parameter is a pointer to the structure where you want the results to be stored, and cbOutput contains the size, in bytes, of this structure. ExtEscape returns a positive value if the call is successful, and 0 if the requested function doesn't exist. A negative return value indicates an error. Several predefined values exist for nEscape, primarily related to printers, but other than these you are free to specify any value supported by the target driver.

"My kid was Inmate of the Month at Adobe Mountain Juvenile Corrections Center" - Bumper Sticker in Bullhead City

Beginner Windows C++ GUI question

Indrawati23-Sep-04 15:58

Indrawati

23-Sep-04 15:58

Hi
I have just started learning C++ GUI programming using Visual C++ (I'm using VC++ 6), and I have two questions regarding it:
1. Let's say I create a dilog-based project, and I put some things (buttons, lists, etc.). The problem is, when the user maximizes the the dialog, the button placements are not automatically modified, leaving a large part of the maximized window blank. Is there a way to automatically reposition ALL the things inside the dialog when the user maximizes the window (or resizes the window, for that matter)? Or do I need to manually recalculate the correct positions and sizes for all the things and apply them one by one?
2.Is there a tutorial/website that explains how I can create other GUIs beside the document/view or dialog-based GUIs that Visual C++ provides (e.g. skin-based GUI, GUI's with shape other than simple rectangle, etc.)?

Thanks!

Re: Beginner Windows C++ GUI question

Christian Graus23-Sep-04 16:42

Christian Graus

23-Sep-04 16:42

Indrawati wrote:
Is there a way to automatically reposition ALL the things inside the dialog when the user maximizes the window

No.

Christian

I have drunk the cool-aid and found it wan and bitter. - Chris Maunder

Re: Beginner Windows C++ GUI question

Ravi Bhavnani23-Sep-04 18:04

23-Sep-04 18:04

MFC doesn't come with a layout manager like Java. However, see this[^] and this[^] CP section for answers.

/ravi

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To Michael Dunn

Guoguor23-Sep-04 15:50

23-Sep-04 15:50

I just want to know the initializtion of the parameter lpCmdLine. Could you tell me how and where to find it?
thanks!

free like a bird

Tim Smith23-Sep-04 16:01

Tim Smith

23-Sep-04 16:01

lpCmdLine is passed into your program from CRT initialization. The CRT just calls GetCommandLine.

Tim Smith

I'm going to patent thought. I have yet to see any prior art.

Guoguor23-Sep-04 16:09

23-Sep-04 16:09

Thank you very much,Tim!

free like a bird

Bob Stanneveld24-Sep-04 0:08

Bob Stanneveld

24-Sep-04 0:08

Hello,

I'm just wondering why your message subject is: "To Michael Dunn"?

Multiply it by infinity and take it beyond eternity and you'll still have no idea about what I'm talking about.

Where and when to initialize them?

Antony M Kancidrowski24-Sep-04 3:38

Antony M Kancidrowski

24-Sep-04 3:38

It may be more appropriate to be "Dear Mr. Dunn"! Poke tongue | ;-P

Ant.

I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Williams (Little Britain)

Guoguor23-Sep-04 15:09

Re: Where and when to initialize them?

23-Sep-04 15:09

Recently, I write a program.And I write a WinMain function for it. But I don't know where and how to initialize the parameters of the function. Should I to initialize them by myself? Or the system will intialize them?
Where can I find the initializtion of the parameters
hInstC,hInstP,lpCmdLine,nCmdShow?
the function is as follows:
int PASCAL WinMain(HINSTANCE hInstC, HINSTANCE hInstP, LPTSTR lpCmdLine, int nCmdShow)
{..................}

free like a Bird

Michael Dunn23-Sep-04 15:15

Michael Dunn

23-Sep-04 15:15

Windows calls WinMain() when your program is run, so it will set up the parameters itself.

--Mike--
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----
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Help writing a function

NietzscheDisciple23-Sep-04 12:11

NietzscheDisciple

23-Sep-04 12:11

Hello All,

I am new to C++ and am trying to do some DSP programming. I would like to write the following function

y(n) = (1-a)*x(n-1) + a*y(n-1)

The arguments to this function are all floats - "x", "y" and "a".

Could somebody help me with this?

Ravi Bhavnani23-Sep-04 12:35

23-Sep-04 12:35

I could help you if you can answer these 2 questions:

(1) is x a function (if so, what is it)?
(2) what's the definition of y(0)?

/ravi

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NietzscheDisciple23-Sep-04 12:44

NietzscheDisciple

23-Sep-04 12:44

Thanks, Ravi.

To answer your questions, this function which I'll call SmoothingFunction, is called by another function by name, SmoothCoeffs().

I have two arrays, Coeff[] and Smooth[], each with 5 elements. Values in the array Coeff[] are "smoothed" and then stored in Smooth[].

Here is the SmoothCoeffs() function:
NUM_ITER is 5.

<br />
inline void cDSP::SmoothCoeffs()<br />
{<br />
   float *nStart = &gnCoeff[mnCoeffIndex];<br />
   float *nFin = &gnSmooth[mnCoeffIndex];<br />
<br />
   for (int i = 0; i < NUM_ITER; i++)<br />
   {<br />
	// CALL SMOOTHING ROUTINE<br />
	SmoothingFunction(nStart, nFin, mnSmoothCoeff);<br />
    }<br />
<br />
    mnCoeffIndex += NUM_ITER;				   // increment coeff index<br />
	<br />
   if (mnCoeffIndex >= NUM_COEFF)<br />
	mnCoeffIndex = 0;				   // reset coeff index if finished with buffer<br />
}<br />

"x" represents an element of Coeff() and "y" represents an element of Smooth().

Hope that helps!

Ravi Bhavnani23-Sep-04 13:31

23-Sep-04 13:31

OK, so that implies x and y are simply floating point values and not functions. But then I'm confused by your original definition, viz:

y(n) = (1-a)*x(n-1) + a*y(n-1)

To me, that says y is a function of n, whose definition includes the value y(n-1). This is pretty easy to code recursively, but then I need to know the exit condition (eg: y(0) is arbitrarily defined as some value). Assuming y(0) is zero, I think the function you want is:

#define EPSILON   0.0000001
double y
  (float n,
   float a,
   float x)
{
  if (fabs (n) < EPSILON)
     return (0.0); // exit condition
  return ((1.0 - a)*x*(n - 1.0) + (a*y(n-1)));
}

/ravi

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