C / C++ / MFC

Re: Manually implement LVSCW_AUTOSIZE_USEHEADER

24-Sep-03 10:39

Wim Jans wrote:
Does anybody know how they calculate the exact width of the text.

CListCtrl::GetStringWidth() would be one way.

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

Wim Jans24-Sep-03 10:49

Wim Jans

24-Sep-03 10:49

And a nice way to do it!
Just fits my needs.

Thanks for that Smile | :)

Scrollbars in a dynamically changing dialog

Member 53435724-Sep-03 10:15

Member 534357

24-Sep-03 10:15

I have a dialog as a child window to a CSizingControlBar. The dialog was created using the resource editor with 5 button controls at the top of it. At run time I dynamically add CListCtrls to it (the number of list controls will vary - depends on how many the user wants). The issue I am having is with the scroll bars when a new control is added while the scroll bar is scrolled down (not at the top position) the list controls get properly added in the right position but when I scroll back to the top of the dialog because I reset my scroll position to 0 before I add the new controls my original static controls are no longer there - They seem to disappear
If anyone can tell me what I am doing wrong I would greatly appreciate it

Thank you

VC++ Debugger

yanmei24-Sep-03 9:56

yanmei

24-Sep-03 9:56

I am getting this very strang problem while tracing my program with VS 6.0 debugger.

my program is written in VC++ 6.0, and it runs fine in release mode and in debug mode if I don't step into any functions.

But,my system looks like dead( freeze, stuck, what ever...) if I try to step into the program. This could happen any where in the program, it even happened at one line which contains only simple assignment statement (like: int x= 1;).

Would anybody give me some clues on this problem? Why do I get this? How to fix it?

Thank you very much in advance! Confused | :confused:

Re: VC++ Debugger

Neville Franks24-Sep-03 10:22

Neville Franks

24-Sep-03 10:22

I see this from time to time, usually when debugging multithreaded apps on XP. Never noticed it on W2K. Ofter press Ctrl+Alt+Del to bring up Task Manager brings it back to life. That is the only solution I've found.

Neville Franks, Author of ED for Windows. Free Trial at www.getsoft.com

GetCheck w listboxctrl (has checkboxes)

ns24-Sep-03 9:52

24-Sep-03 9:52

Which message do I need? I am trying NM_CLICK, and in that handler I check to see if any of my items is checked (have checkboxes). Problem is, the first item I click, triggers the event and the code steps into the function where I look for a checked item:

void CDlgFTP::OnClickLstftp(NMHDR* pNMHDR, LRESULT* pResult) 
{
	for( int index = 0; index <  m_lstFiles.GetItemCount(); index++)
	{
		BOOL chk = m_lstFiles.GetCheck(index);
		if (chk)
		{
		  	m_bGet.EnableWindow(TRUE);
		}

	}	
	*pResult = 0;
}

but this time around, chk is 0, but when I check the second item, and step into the code, the chk for element # 1 becomes 1, since its now checked. SO it looks like I am triggering my checkbox checking code prematurely. What message should I use instead?

Basically I want a button to get enabled when any item is selected in the listctrl.

Thanks,
ns

Dialog menu problem...

LukeV24-Sep-03 8:17

LukeV

24-Sep-03 8:17

Hi!

I added a menu to my dialog (through the Wizard) and I can't get any command notification from it.

ON_COMMAND(ID_SOME_COMMAND, OnSomeCommand)

void CSomeClass::OnSomeCommand()
{

}

OnSomeCommand never gets called. I did notice, however, that I do get a message in my DefWndProc function (message 273) but lParam = 0, when it should equal ID_SOME_COMMAND. What's wrong?

I'm using MFC's CDialog class...

Thanks for your help! Smile | :)

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David Crow24-Sep-03 8:22

24-Sep-03 8:22

Is CSomeClass a CDialog-derived object?

Is ID_SOME_COMMAND assigned to any of the menu items?

LukeV wrote:
...I do get a message in my DefWndProc function...

Are you using .NET?

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

LukeV24-Sep-03 8:28

LukeV

24-Sep-03 8:28

I'm using MFC's CDialog class...

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RChin24-Sep-03 8:46

RChin

24-Sep-03 8:46

I think this relates to your problem, but may not solve it:

http://support.microsoft.com/default.aspx?scid=kb;en-us;242577[^]

It basically describes the problem whereby the UI menu updates will not work for dialog based application.

I Dream of Absolute Zero

Need help with multi-dim arrays please

LukeV24-Sep-03 9:49

LukeV

24-Sep-03 9:49

Found the problem... I was using ModifyMenu to change the menu item's text, and it was setting the ID to 0.

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Flack24-Sep-03 7:51

Flack

24-Sep-03 7:51

In a header file of one of my classes I have a private two dim array,

<br />
double V[][6] = {<br />
      {-.01,0,0, -.2,-.2,1},  // POINT AND NORMAL<br />
      {.1,0,0, .2,-.2,1},<br />
      {0,.11,0,  -.2,.2,1},<br />
      {.08,.09,0,  .2,.2,1}<br />
   };<br />

but this gives me a compiler error. It says "syntax error : '{'" and
"unexpected token(s) preceding '{'; skipping apparent function body".
Does anyone know why? All I want to do is declare and initialize it.

Also, lets say I have a 3-dim array, (which I cant initialize either until I fix my first problem)

<br />
double polygon[][][] = {<br />
      { V[0], V[1], V[2] },<br />
      { V[1], V[2], V[3] }<br />
   };<br />

and I need a for loop to go thru polygon. I want to do something like:

<br />
for (int n = 0 ; n < polygon.length ; n++)<br />
  for (int i = 0 ; i < polygon[n].length ; i++) {<br />
    for (int k = 0 ; k < 3 ; k++)<br />
       normal[k] = polygon[n][i][k+3];<br />

What do I replace the bold & underlined with? Would it be sizeof(polygon)/sizeof(polygon[0]) for the outer loop and sizeof(polygon[0])/sizeof(polygon[0][0]) for the inner?

This stuff confuses me.

Thanx for the help,
-Flack

David Crow24-Sep-03 8:20

24-Sep-03 8:20

I got no errors with your two-dimensional array.

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

Flack24-Sep-03 8:34

Flack

24-Sep-03 8:34

Here is the entire header file:

<br />
/*<br />
   Extremely simple example of zbuffer algorithm<br />
*/<br />
#include <windows.h><br />
#include <math.h><br />
#include "Pix.h"<br />
<br />
class ZBuffer1 {<br />
// THE SCENE<br />
<br />
	private:<br />
	// ALL VERTICES IN THE SCENE<br />
	double V[][6] = {<br />
        {-.01,0,0, -.2,-.2,1},  // POINT AND NORMAL<br />
        {.1,0,0, .2,-.2,1},<br />
        {0,.11,0,  -.2,.2,1},<br />
        {.08,.09,0,  .2,.2,1}<br />
        };<br />
<br />
	// ALL POLYGONS IN THE SCENE - THESE REFER TO THE VERTICES<br />
	double polygon[3][3][3];<br />
<br />
	// ALL LIGHT SOURCE DIRECTION VECTORS IN THE SCENE<br />
	double L[1][3];<br />
<br />
	double rgb[3];<br />
	double p[30][7]; // TEMPORARY STORAGE FOR SHADED PROJECTED POLYGON<br />
<br />
	// THE RENDERER<br />
	double FAR_Z; // BACKGROUND Z<br />
	double * zbuffer;<br />
	double normal[3];<br />
<br />
	int W, H;<br />
<br />
	// INITIALIZE EVERYTHING ON START<br />
	void init();<br />
<br />
	// CLEAR THE ZBUFFER AND IMAGE<br />
	void clearZbuffer();<br />
<br />
	// PROJECT ONE {X,Y,Z,Nx,Ny,Nz} VERTEX ONTO THE IMAGE PLANE,<br />
	// AND SHADE IT, TO CREATE A {Px,Py,Pz,Red,Green,Blue} VECTOR<br />
	void projectVertex(double pt[], double p[]);<br />
<br />
	// VERY ELEMENTARY VERTEX SHADER (JUST A PLACE-HOLDER)<br />
	// THIS SHOULD BE REPLACED BY A TRUE PHONG SHADING ALGORITHM<br />
	void doShading(double pt[], double rgb[]);<br />
<br />
	// DISPLAY ONE POLYGON<br />
	void displayPolygon(double polygon[][3]);<br />
<br />
    // GENERIC UTILITY ROUTINES<br />
<br />
	// NORMALIZE A VECTOR<br />
	void normalize(double v[]);<br />
<br />
	// LINEAR INTERPOLATION<br />
	double lerp(double t, double a, double b) {return a + t * (b - a);}<br />
<br />
	// CONVERT A FLOATING POINT VALUE INTO A 0..255 INTEGER<br />
	int f2i(double t) {return max(0, min(255, (int)(255 * t)));}<br />
<br />
	public:<br />
	Pix pix;<br />
<br />
	ZBuffer1(int, int);<br />
	// THIS IS CALLED EVERY FRAME TO RENDER THE IMAGE<br />
	void setPix();<br />
};<br />

I try to compile and still get an error on the underlined line:
zbuffer1.h(14) : error C2059: syntax error : '{'
zbuffer1.h(14) : error C2334: unexpected token(s) preceding '{'; skipping apparent function body

I dont know what Im doing wrong.

David Crow24-Sep-03 9:04

24-Sep-03 9:04

Flack wrote:
I dont know what Im doing wrong.

You are trying to initialize that array within the class itself. Try this:

class ZBuffer1
{
private:
    double V[][6];
public:
    ZBuffer1();
};
 
ZBuffer1::ZBuffer1()
{
    V[0][0] = -0.01;
    V[0][1] =  0.0;
    V[0][2] =  0.0;
    V[0][3] = -0.2;
    V[0][4] = -0.2;
    V[0][5] =  1.0;
 
    V[1][0] =  0.1;
    V[1][1] =  0.0;
    V[1][2] =  0.0;
    V[1][3] =  0.2;
    V[1][4] = -0.2;
    V[1][5] =  1.0;
 
    V[2][0] =  0.0;
    V[2][1] =  0.11;
    V[2][2] =  0.0;
    V[2][3] = -0.2;
    V[2][4] =  0.2;
    V[2][5] =  1.0;
 
    V[3][0] = 0.08;
    V[3][1] = 0.09;
    V[3][2] = 0.0;
    V[3][3] = 0.2;
    V[3][4] = 0.2;
    V[3][5] = 1.0;
}

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

JWood24-Sep-03 8:39

JWood

24-Sep-03 8:39

I think you have to first accept that this is not very easy to do in C/C++. A 2D array is an array of pointer to more arrays. In a declaration you can only have one unknown dimension []. So your second example will not compile. The first one might be an error related to

The rest must be specified. V is a pointer to a pointer, V[n] is a pointer and v[n][m] is a value. The [m] operator is saying advance i + k*m spaces to obtain the location.

You need to either dynamically allocate this with multiple news or allocs, or use constants to create the space in memory in the first place, so it is far easier just to store the dimensions in an integer and use this in your loops.

J.
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