ListCtrl/ListView help wanted. I think??? - C / C++ / MFC Discussion Boards

use the atoi or atol functions.

iWidth = atoi(strWidth);

Or you could use strtod() and strtol().

strtol() is useful if you want to read a number that is not in base 10. For example
to read hex numbers use strtol("0x12345678", NULL, 16)

_tcstol() and _tcstod() are the macros for UNICODE/MBCS portability

Stephen Kellett
--
C++/Java/Win NT/Unix variants
Memory leaks/corruptions/performance/system problems. UK based.
Problems with RSI/WRULD? Contact me for advice.

int nWidth = 110; <br />
CString strWidth; <br />
strWidth.Format ( "%d", nWidth ); // like the sprintf function

-Ben

---------
On the topic of code with no error handling -- It's not poor coding, it's "optimistic" Wink | ;)

Use function StrToInt this way

int nWidth=StrToInt(strWidth);

just one line of code and u got inr value.;)

Gonna be 18 till I die

Two problems. First, why use a non standard function when atoi works perfectly well, and second ( from MSDN)

Windows NT/2000: Requires Windows 2000 (or Windows NT 4.0 with Internet Explorer 4.0 or later).
Windows 95/98: Requires Windows 98 (or Windows 95 with Internet Explorer 4.0 or later).

Sounds like a bad idea to me, unless you specifically do not target the platforms not supported, and even then I would personally prefer not to get into the habit of using something I may find unavailable to me down the track, for no good reason I can see.

Christian

#include "std_disclaimer.h"

People who love sausage and respect the law should never watch either one being made.

The things that come to those who wait are usually the things left by those who got there first.

I need to color 3D graphic object, the graphic object is described by multiple triangles in variable size. I need to color this 3D object. Color will be variable based on the different
heighth (Z coordinate) of the 3D dimension, but the parts which are in the same height must be in the same color. How to color this graphic object? Please help me.

Since you can set a color for each vertex of the mesh, this doesn't seem to be a problem. Just set the color as a function of the z for each vertex :
...
glColor3f(R(z),G(z),B(z));
glVertex(x,y,z);
...
where R,G,B are mapping of z

Jonathan de Halleux, Belgium.

I am currently writing a Dialog based application that sits atop a database. In the summary screens I use a ListCtrl to display all records from a given table that can be selected to then take us to the detail screen. Using advice previously administered from this forum I have set the width of column one to zero, this is to hide the tables Primary Key from the user, while still having it available to me to use when next accessing the record in the database.

In a particular table I have an Order column for use in reports that the user, uses to set the order. I want to create a seperate screen where the user can reorder the records. This is where I have run into my current problem, how do I achieve this what is the best control for me to use.

I envisaged using the ListCtrl, which has become my friend in this project. I would display the Customer (with hidden Primary Key), allow them to re-order the list and then I would cycle through the records updating them sequentially with the new order value.

Problem is the SetItemPosition() function only works when in Icon or Small Icon mode and SetExtendedStyles only has drag and drop ability on rows not columns. Of course I am using Report mode and need to re-order the rows not columns. This stops me from using drag and drop or Up/Down command buttons to enable the re-ordering.

I also thought about using a ListView, but if I didn't want to have the Primary Key visible I would have to create a map and store it in an array external to the ListView. This would force me to keep track of the order of two things to achieve the result I want. Thats one to many for my brain that is running low on RAM at the moment.

What have I missed? I'm sure it is obvious, but not to me. How should I be doing this? Preferably I would like to be able drag the row into it's new position. Any help much appreciated. What's the answer?

Thanks in advance for the help.

P.S. All humour, sarcasm and colloquialisms removed so as not to confuse or offend. Also as a test to see if this question gets an answer this time.

Michael Martin
Pegasystems Pty Ltd
Australia
martm@pegasystems.com
+61 413-004-018

The only built-in control that does drag & drop of rows is CDragListBox, but that's derived from a listbox (old Win 3.1 control) not a list view control, so if you need to keep the report style UI of the list view control, CDragListBox won't do it for you.
The list view control doesn't have any built-in reordering support, unfortunately. (Well, version 6 of the common controls does, but that only works on XP.)

--Mike--
http://home.inreach.com/mdunn/
"Holding the away team at bay with a non-functioning phaser was an act of unmitigated gall. I admire gall."
-- Lt. Cmdr. Worf

Mike

thanks for the help CDragListBox seems to be what I was looking for. MSDN says that I can have columns and set their width so I should be able to keep the Primary Key in the row data which is what I was looking for. It also tells me that I just add a ListBox to my dialog in the editor and then in ClassWizard set a control variable of type CDragListBox. Problem is that I only have CListBox as a choice. I am going to add CListBox and then manual edit the code to use CDragListBox and hope that this works.

Any idea why these other choices aren't appearing? Is it a setting I can modify or maybe a header I am missing in the project?

I have noticed other strange things that have hapened over time. A couple of years ago when I would create an app with a DropList ComboBox I would have the option of selecting a CString as a value variable, while now I only get int. I then have to change the int to CString and hack the DDX section of the code to get it to return the selected string and not zero based index when I do UpdateData(TRUE);

Did these changes appear while I was sleeping for the past couple of years or have I just screwed up something simple yet again?

Michael Martin
Pegasystems Pty Ltd
Australia
martm@pegasystems.com
+61 413-004-018

I need to print a metafile to a specified rectangle on the printer DC. I am using the PlayEnhMetaFile(...) function to paint the metafile to the DC. This works except the RECT passed into the API call is in logical units (I believe) and the printer DC is something else. How do I get one or the other into the same coordinate system?

TIA!

hello everyone,

here is my situation. I have a document view app. in the view I create an edit control programatticaly and make it appear at a certain point. When I call CEdit::create I pass "this" as the parent window. Thus, the newly created edit control is a child of the view (i think). What I want to be able to do however, is when I click back on the document the text box which pops up should dissapear. However this simply doesnt happen, its as though the popped up text box is modal to the view. I think this is happening because the text box is being created "on" the view it is almost as if the view doesnt lose focus. Thus, clicking back on it doesnt cause the view to throw any focus related messages... Hope this is clear....

Andreas

Yes, of course. That's how controls work. The problem is that your view cannot have focus by itself. The easiest way to do this would be to handle the onclick event of the view and deactivate the edit control.

I have been looking at how I would do this and keep on finding the same code - that you would derive from CEDit and override WM_CHAR messages, and check for VK_ESCAPE, however take a look at this code:

void CEditExtended::OnChar(UINT nChar, UINT nRepCnt, UINT nFlags)
{
MessageBox("Character message thrown!");

switch( nChar )
{
case VK_ESCAPE :
{
MessageBox("Escape");
break;
}
case VK_RETURN :
{
MessageBox("Return!");
break;
}
default :
{
CEdit::OnChar(nChar, nRepCnt, nFlags);
break;
}
}

CEdit::OnChar(UINT nChar,UINT nRepCnt,UINT nFlags);
}

Pressing the escape key simply isnt throwing these messages, why would this be?? Any idea how I can do this? (i know everything else is it set up right because if i press another key then this function gets called so its nothing like that)

any help very much appreciated!

thanks

Hi Anon,

I think you might find that your App (which I suspect is a wizard generated Dialog App) is actually generating a WM_CLOSE or WM_CANCEL. The easiest way to fix your problem is to put a check in you OnClose method.

It should look something like :
if (GetKeyState() & VK_ESCAPE = VK_ESCAPE)
return;
CDialog::OnCancel();

Let us know if you getting it working & how.

Julien.

Opps

Try this :

BOOL CYourDialog::OnCommand(WPARAM wParam, LPARAM lParam)
{
//////////////////////////////////////////////////////////////
// Prevent Enter and ESC from closing the control.
//////////////////////////////////////////////////////////////
if (wParam == IDOK)
return FALSE;
if (wParam == IDCANCEL)
return FALSE;

return CDialog::OnCommand(wParam, lParam);
}

J

One way to catch the escape key is to overide PreTranslateMessage and before calling the base class PreTranslateMessage, look for a message w/msg = WM_KEYDOWN and wParam = VK_ESCAPE. Then, I usually translate the message into a MYMSG_CUSTOM_ESCAPE message and post that message back to me and return without calling the base class. See sample below.

BOOL CMyWnd::PreTranslateMessage(MSG* pMsg)
{
BOOL bCallBaseClass = TRUE;

if (pMsg->message == WM_KEYDOWN && pMsg->wParam == VK_ESCAPE)
{
PostMessage(MYMSG_CUSTOM_ESCAPE);
bCallBaseClass = FALSE;
}

if (bCallBaseClass)
BOOL CWnd::PreTranslateMessage(pMsg);

return TRUE;
}

LRESULT CMyWnd::OnMyCustomEscape(WPARAM wParam, LPARAM lParam)
{
// TO SOMETHING

return 0;
}

My "this" pointer in my DLL is getting f*ck up,.. I don't know why.
I have create a small 72K zipped test application and dll that shows
this problem.

download it here.

www.marino.dk/misc/dlltest01.zip

run the application, and click on the 'help' menu and then the 'testme2'
menu item. Here you should get an example of a "this" pointer being destroyed.

Plz somebody help me,

Peter Marino ( IO Interactive )
www.marino.dk

I don't understand what your objective is but I won't beat you about that.

You are making a comparison of g_lpThis to an uninitialized this pointer in the CDeleteMeDLLApp::Start2 method.

Your DLL is being loaded and initialized during the first call to LoadLibrary but this does not mean that you have an instance of the CDeleteMeDLLApp class on which you may make method calls. You are getting a raw pointer to the CDeleteMeDLLApp::Start2 method export and basically callin into very dangerous territory.

Please explain more about what you are trying to do and I think we can all help you better.

Cliff

ok,... it sounds like I have completly misunderstood how the a dll should work. The Start2 test is comparing the g_lpThis pointer to the actual this pointer,... which isn't the same,.. why isn't it the same, that is my question.

Ok, I got an answer at Codeguru,... it's because my Start2 is seen from the App as a "C" call and not a "C++" object call CDeleteMeDLLApp::Start2. This explains it. Which in turn also gives you the correct answer when you tell me that I don't have an instance of the CDeleteMeDllApp,.. well there is an instance, I just don't have it in my App program.

thx a lot. now I can sleep Smile | :)

Peter Marino
www.marino.dk

The "This" pointer in a member function of a class is actually an 'invisible' first parameter passed to the function by the compiler. For example, when you write the function :

void CDeleteMeDLLApp::Start2( unsigned long dwDummy1, unsigned long dwDummy2 )

The compiler actually generates this as if it was :

void CDeleteMeDLLApp::Start2(CDeleteMsDllApp* this, unsigned long dwDummy1, unsigned long dwDummy2 )

The problem here is that inside the DLL you are saying that "start2" is a class member function (and therefore has this 'invisible' first parameter called "this"). However, in the App you are telling the compiler it is a normal 'C/C++' function (and therfore it does not have a "this"). When the compiler generated the call to "Start2" is does not add the "this" bexcause it is not aware that "Start2" is a class member (and even if it was aware, the compiler does not now the address of the class instance 'theApp' at this point - only the DLL knows that. So the compilter cannot pass the address even if it knew it should)

To correct this you must resolve this inconsistent view of the function - either make it a member in both places, or a non member in both places. You have 3 choices :

(a) Use non-member functions in the dll, rather than class members;
(b) Make the member functions 'static', so they do not have a 'this' pointer;
(c) export the class from the DLL, rather than the individual member functions. When I do this, I often export a function that returns a pointer to the class, like this :

In the Dll :

CDeleteMeApp* declspec( dellexport) getClass() { return &theApp; }

In the app :

typedef CDeleteMeDll* (CALLBACK* GETCLASS)();
GETCLASS getClass;

HLIB lib = LoadLibrary("deleteMeDll");
getClass = (GETCLASS)GetProcAddress("getClass");
CDeleteMeDLL* theClass = getClass();

theClass->Start(pWnd);
theClass->Start2(1, 2);

You need to rework you interface between the DLL and the App - either make it 'c-style', and export 'normal' functions (you can of course make these exported functions into 'wrapper' functions that simply call the appropriate class member function !), or make it 'C++ style', and export the class, not the member functions. Either way, the bottom line is to avoid exporting class member functions!!

The root of this is that DLLs were invented before C++ was in widespread use, and therefore the DLL architecture has no knowledge of the concept of 'class' - DLLs were designed to hold code (functions) and data as separate elements, not classes (a hybrid mix of code and data). Microsoft has addressed this with the 'declspec (dllexport)' extension to C++ which basically allows you to export an entire class (the compiler will do the necessary work to map from C++ back onto the DLL-style function/data model).

Hello

Does anybody knows how can I catch Input and Output Internet traffic ?

Regards

Read more about it at ... and let me know what you think!

I think that spamming message boards is a very poor way to get people to buy your software, but maybe that's just me. Go to http://www.codeproject.com/info/advertise.asp if you want to advertise here.

--Mike--
http://home.inreach.com/mdunn/
"Holding the away team at bay with a non-functioning phaser was an act of unmitigated gall. I admire gall."
-- Lt. Cmdr. Worf

Is it possible to define a customized syntax highlighting in Visual Studio ? I want some keywords to be green, and some to be red. Thanks for the answers. Rose | [Rose]

If you mean custom words then I'm not sure if that is possible but if you wish to recolorize the currently supported syntaxses (sp) you can go into Tools->Options and you change the colorization there.

Hope that helps. Smile | :)

Sean Cody (NullStream)
"As long as you want to live,
everywhere will become heaven.
Afterall, you are still alive."
- End Of Evanglion