|
Hello,
I'm following this tutorial for MFC/C++: http://www.codeproject.com/listctrl/creportctrl.asp . This concerns implementing a CListCtrl-derived class with certain "out of the box" functionality that the MFC "report style" CListCtrl lacks. For example, the user can re-order items by clicking on a column header, and, optionally, the programmer can include a checkbox beside nodes.
I created a dialog that uses this CReportCtrl, but that didn't work - I could see entries, but there were no headings, and no lines, even though I'd called the SetGridLines() member function.
I then called ModifyStyle(0,LVS_REPORT), which is meant to be used with the CListCtrl base class. Now, CReportCtrl was mostly fully functional. The column headers were visible. When I called SetGridLines(TRUE), gridlines appeared. However, one last important piece of functionality was still missing: I couldn't re-order column entries by clicking on a column header, in the style of windows explorer.
I can confirm that the function(OnColumnClick) is called when I click on a column header. I can confirm that _CompareFunction is *not* being called.
Most recently, I changed the List dialog item properties view from "Icon" to "Report". This had the effect of causing all sorts of errors such as "Unhandled exception at 0x78144580 in Lustre.exe: 0xC0000005: Access violation reading location 0x0aa30324" when I debugged. Apparently, this was the offending code:
int CReportCtrl::InsertItem(int nIndex, LPCTSTR pszText, ...)<br />
{<br />
const int iIndex = CListCtrl::InsertItem(nIndex, pszText);<br />
<br />
if (!_IsValidIndex(iIndex))<br />
return iIndex;<br />
<br />
CStringArray arr;<br />
arr.Add(pszText);<br />
<br />
va_list list;<br />
va_start(list, pszText);<br />
<br />
for(int iColumn = 1; iColumn < GetColumnCount(); iColumn++)<br />
{<br />
LPCTSTR lpsz = va_arg(list, LPCTSTR);<br />
CString str = (lpsz == NULL) ? _T("") : lpsz;<br />
arr.Add(str);
CListCtrl::SetItemText(iIndex, iColumn, str);<br />
}<br />
<br />
va_end(list);<br />
<br />
_AssignNewItemData(iIndex, arr.GetData(), arr.GetSize());<br />
<br />
return iIndex;<br />
}
I'd be very grateful if someone could point me in the right direction. I suspect this has something to do with the fact that I am using visual studio 2005, and this tutorial was created with visual studio 6,
Thanks a lot,
Sternocera ( ( (
|
|
|
|
|
Sternocera wrote: arr.Add(str); // This particular line was flagged by visual studio
As what?
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
You know when you're debugging and you get the little green arrow that highlights the offending code? Thats what I meant by flagged.
|
|
|
|
|
So what is the value of str at that point?
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
At that juncture, the value of str is "‹ÿU‹ìV‹u ÷Æ"
Hope that helps 
|
|
|
|
|
Sternocera wrote: for(int iColumn = 1; iColumn < GetColumnCount(); iColumn++)
{
LPCTSTR lpsz = va_arg(list, LPCTSTR);
If you are not 100% sure you know what you are doing that is a very very bad idea.... it might be anyway
|
|
|
|
|
I didn't write the code. As stated, it is from a codeproject tutorial. Could you elaborate on why it is (potentially)such a bad idea?
|
|
|
|
|
Sternocera wrote: it is from a codeproject tutorial.
Which one? Post a link.
Sternocera wrote: Could you elaborate on why it is (potentially)such a bad idea?
The arg list is not infinite and the function relies on the number of columns matching the number of arguments. If they aren't, which appears to be what you are experiencing, I don't believe the test for NULL is not going to work because that is not how va_arg() works. I believe it will just keep reading memory beyond the end of what was actually provided by the caller.
|
|
|
|
|
The codeproject tutorial in question is http://www.codeproject.com/listctrl/creportctrl.asp[^]
I think you're right about it reading memory beyond its bounds. That would be consistent with str cotaining all that garbage. Could you suggest a solution?
Regards,
Sternocera
|
|
|
|
|
Sternocera wrote: Could you suggest a solution?
Call InsertItem() with a count of the number of variable arguments.
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
I'm currently calling InsertItem in this fashion:
SampleReportCtrl.InsertItem(0, _T("test1"));
SampleReportCtrl.InsertItem(1, _T("test2"));
SampleReportCtrl.InsertItem(2, _T("test3"));
How could I call InsertItem() with a count of the number of variable arguments?
Thanks
Sternocera
|
|
|
|
|
Sternocera wrote: How could I call InsertItem() with a count of the number of variable arguments?
SampleReportCtrl.InsertItem(0, 1, _T("test1"));
SampleReportCtrl.InsertItem(1, 1, _T("test2"));
SampleReportCtrl.InsertItem(2, 1, _T("test3"));
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
|
Sternocera wrote: There are 3 columns
But you were calling InsertItem() with only one variable argument, hence the 1 that I supplied. If you wanted to call it with three arguments, you would need to do:
SampleReportCtrl.InsertItem(0, 3, _T("test1"), _T("test2"), _T("test3"));You would obviously need to change the method's signature for this to work properly. Your solution of making the last argument 0 is probably a bit cleaner, however.
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
InsertItem is an overloaded function. I found by calling it in this manner:
SampleReportCtrl.InsertItem(0, _T("test1"),0);
SampleReportCtrl.InsertItem(1, _T("test2"),0);
SampleReportCtrl.InsertItem(2, _T("test3"),0);
everything worked nicely. Thanks!
|
|
|
|
|
Sternocera wrote: I found by calling it in this manner:
SampleReportCtrl.InsertItem(0, _T("test1"),0);
SampleReportCtrl.InsertItem(1, _T("test2"),0);
SampleReportCtrl.InsertItem(2, _T("test3"),0);
everything worked nicely.
Which creates 3 rows and 1 column.
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
Yes. Thanks for your help, David.
|
|
|
|
|
how many columns are there in the list control?
|
|
|
|
|
Hai All,
Can anybody please expalin me a way.I'm having a handle value(say hnd) to a dialog.I want to acess the controlls of that dialog (say edit control).I know the ID (say IDD1)of the controll also.But when I'm using the ::GetDlItem(hnd,IDD1) it is showing unreferenced memory.
MyCode is like this
hnd=::GetForegroundWindow();
HWND hWnd = ::GetDlgItem(hnd, IDD1);
CEdit* pEdit = (CEdit*)CWnd::FromHandle(hWnd);
pEdit->SetWindowText("HELLO");
My intenetion is to change the text of the edit controll(IDD1).
Thanks in advance
Robs here
|
|
|
|
|
Wheres the edit control if its on the current dialog you can use of Id of editcontrol you enter Id of edit control on GetDlgItem and dont need to ID of Dialog.
|
|
|
|
|
robshere wrote: hnd=::GetForegroundWindow();
HWND hWnd = ::GetDlgItem(hnd, IDD1);
CEdit* pEdit = (CEdit*)CWnd::FromHandle(hWnd);
You are not checking the return value of any of these functions. Why?
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
I have a PC connected via HDMI to my TV but after a period with the TV on another input the PC's HDMI output switches off.
Is there a function I can call to force a display detection again as this sorts things out?
It's an ATI Radeon Express 1250 on a motherboard by the way.
Thanks.
Elaine ![Rose | [Rose]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/rose.gif)
|
|
|
|
|
*If* its ACPI causing the port to power down, can't you just disable ACPI in the BIOS? Try it and see if it helps.
-Randor (David Delaune)
|
|
|
|
|
 I want to write a program that would swap the left and right audio channel system wide (regardless of audio/video player). This is not a program that plays audio/video files, but works kind like a filter, any audio that outputs to the speaker/headphone should be affected by this program. Is this possible? if so, can someone point me in the right direction on how this could be done.
What should I look into? directsound? audio driver?
I only want to write this because I couldn't find any program that would do this. If such program exist, what is the name of the software?
Thanks
hi
|
|
|
|
|
often the driver of the audio card give you a boolean flag to choose if you want to reverse the speakers. Take a look to the control panel before start to write the program.
Russell
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
