C / C++ / MFC

11-Dec-02 8:32

Hi,

I need to output some CString data after I've copied it to a char array (ie: char ptrSomeCharArray[33]). I can't seem to get the data extracted from the CString object.

I've tried:

CString m_sFullname("Like2Byte"), m_sAccount("12345678"), m_sRoom("222");
char SomeCharArray[33];

sprintf( SomeCharArray + strlen(SomeCharArray), "%s", m_sAccount);
sprintf( SomeCharArray + strlen(SomeCharArray), "%s", m_sRoom);
sprintf( SomeCharArray + strlen(SomeCharArray), "%s", m_sFullname);

While this compiles without error, inserting it into a
MessageBox function displays garbage. Even wrapping the var in TEXT() doesn't work. I've also tried casting using LPCTSTR, LPTSTR and (const char*). None work correctly.

Anyone help out?

User 665811-Dec-02 8:43

User 6658

11-Dec-02 8:43

Have you tried e.g. sprintf( SomeCharArray + strlen(SomeCharArray), "%s", m_sAccount.GetBuffer(0)); ?

But err, what does the sprintf do? Do you want to append the CString to SomeCharArray? You should use strcat instead

regards

modified 12-Sep-18 21:01pm.

Like2Byte11-Dec-02 8:49

11-Dec-02 8:49

Well, I tried m_sAccount.Mid(0) but that gave me the same results are m_sAccount.

Let me try your suggestion.
(The 'In a nut-shell' explination)sprintf basically copies whatever kind of data to end of another string converting it to a string when it's all done.
say, SomeCharArray contains "HelloWorld" and someIntValue = 32768.
Therefore, sprintf(SomeCharArray + strlen(SomeCharArray), "%i", someIntValue); copies 32768 to the end of SomeCharArray; thus, leaving, "HelloWorld32768".

(BRB)

Michael Dunn11-Dec-02 8:49

Michael Dunn

11-Dec-02 8:49

Any time you use a string object (CString or any other string wrapper class) with the printf family of functions, you need to cast the object to a pointer type, so that only the pointer is put on the stack.

sprintf( SomeCharArray + strlen(SomeCharArray), "%s", (LPCTSTR) m_sAccount);

But as Gregor said, the real bug in your code is how you construct the string in the first place. Just use one sprintf() call.

--Mike--
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Like2Byte11-Dec-02 8:51

11-Dec-02 8:51

Of all the places I put (LTCTSTR), I *don't* think I placed it right there. Roll eyes | :rolleyes:

(BRB)

Alvaro Mendez11-Dec-02 8:56

Alvaro Mendez

11-Dec-02 8:56

You can use strcpy, like this:

strcpy(SomeCharArray, m_sAccount + m_sRoom + m_sFullname);

However, you need to be careful that the length of the 3 variables does not surpass the size of SomeCharArray - 1.

Regards,
Alvaro

Well done is better than well said. -- Benjamin Franklin
(I actually prefer medium-well.)

carrie11-Dec-02 10:39

carrie

11-Dec-02 10:39

yeah, thats the method I would use. Nice and easy Smile | :)

Gary R. Wheeler11-Dec-02 14:55

Gary R. Wheeler

11-Dec-02 14:55

You need to initialize SomeCharArray to an empty string, either via

SomeCharArray[0] = '\0';

strcpy(SomeCharArray,"");

otherwise, you're concatenating at an arbitrary location in the string. Another way to do this would be

sprintf("%s%s%s",m_sAccount,m_sRoom,m_sFullname);

Software Zen: delete this;

Shay Harel11-Dec-02 17:36

Shay Harel

11-Dec-02 17:36

Try this :

CString str="Hello";
char *pStr=str.GetBuffer(0);

Thsi should return a pointer of type char representing the string content, always works for me.

Shay

Like2Byte12-Dec-02 3:04

Handling Checkbox changes in CListCtrl

12-Dec-02 3:04

Well, I appreciate *everyones* help. Big Grin | :-D

I also went over to CodeGuru and found this other method.

Again, thanks.

DRHuff11-Dec-02 7:13

DRHuff

11-Dec-02 7:13

I have a CListCtrl in report mode with checkboxes. With several lines of data I can check/uncheck the check boxes without shifting the selection or getting any update other than an ItemChanged update. I need the checkbox change to be reflected back and set the current selection to the item changed. How do I do this?

I have tried to handle it in the OnItemChanged but I get some really bizarre behaviour.

Dave Huff

Igor would you give me a hand with the bags?

Certainly - you take the blonde and I'll take the one in the turban!

Joan M11-Dec-02 7:38

Joan M

11-Dec-02 7:38

take a look at this link...
http://www.codeproject.com/listctrl/listctrldemo.asp[^]

hope this helps...

DRHuff11-Dec-02 7:52

DRHuff

11-Dec-02 7:52

Nope it doesn't.

It tells me how to use GetCheck and SetCheck but it doesn't tell me how to pick up on the change as it is being done.

I am also having a problem similar to one described a few posts down where I have the element selected and when I hit the down key it places me back to the first element in the list. But when I hit the up arrow it works just fine! Mad | :mad:

Thanks

Dave Huff

Igor would you give me a hand with the bags?

Certainly - you take the blonde and I'll take the one in the turban!

Alvaro Mendez11-Dec-02 8:28

Alvaro Mendez

11-Dec-02 8:28

Here's some very old code I dug up that handles this. I don't remember how it works -- that's how long it's been -- but I hope it helps.

// Handle the ItemChanged message.
void CMyDlg::OnItemchangedListParts(NMHDR* pNMHDR, LRESULT* pResult) 
{
	NM_LISTVIEW* pNMListView = (NM_LISTVIEW*)pNMHDR;
	*pResult = 0;
 
	if (HasCheckboxChanged(pNMListView))
		UpdateControls();
}
 
// Check if the checkbox in the given item has changed.
bool CMyDlg::HasCheckboxChanged(NM_LISTVIEW* pNMListView, bool* pbChecked = NULL) const
{
	ASSERT(pNMListView);
 
	if (pNMListView->uOldState == 0 && pNMListView->uNewState == 0)
		return false; // No change
 
	BOOL bPrevState = (BOOL)(((pNMListView->uOldState & LVIS_STATEIMAGEMASK)>>12) - 1);   // Old check box state
	if (bPrevState < 0)     // On startup there's no previous state 
		bPrevState = 0; // so assign as false (unchecked)
 	
	// New check box state
	BOOL bChecked=(BOOL)(((pNMListView->uNewState & LVIS_STATEIMAGEMASK)>>12) - 1);   
	if (bChecked < 0) // On non-checkbox notifications assume false
		bChecked = 0; 
 
	if (pbChecked)
		*pbChecked = !!bChecked;		
	return (bPrevState != bChecked);
}

Regards,
Alvaro

Well done is better than well said. -- Benjamin Franklin
(I actually prefer medium-well.)