CXTListBase::AddColumn -- ItemCount = 0?

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   From toolkit v11 -- In AddColumn, this code:

 int iIndex = pHeaderCtrl->GetItemCount();
 if (nWidth == -1 && iIndex >= 0 )
 {
  // Get the column width of the previous column from header control
  HD_ITEM hd_item;
  hd_item.mask = HDI_WIDTH;               //indicate that we want the width
  pHeaderCtrl->GetItem(iIndex - 1, &hd_item);
  nWidth = hd_item.cxy;
 }

doesn't get a valid hd_item when iIndex = 0!

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scruzer Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 01 February 2008 Location: United States Status: Offline Points: 13	Post Options Post Reply Quote scruzer Report Post Thanks(0) Quote Reply Topic: CXTListBase::AddColumn -- ItemCount = 0? Posted: 19 May 2008 at 2:42pm
	From toolkit v11 -- In AddColumn, this code: int iIndex = pHeaderCtrl->GetItemCount(); if (nWidth == -1 && iIndex >= 0 ) { // Get the column width of the previous column from header control HD_ITEM hd_item; hd_item.mask = HDI_WIDTH; //indicate that we want the width pHeaderCtrl->GetItem(iIndex - 1, &hd_item); nWidth = hd_item.cxy; } doesn't get a valid hd_item when iIndex = 0!

Smucker Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 02 February 2008 Status: Offline Points: 156	Post Options Post Reply Quote Smucker Report Post Thanks(0) Quote Reply Posted: 19 May 2008 at 6:11pm
	Perhaps because you asked it to get item iIndex - 1. As good practice, you may also want to zero any structure you pass to APIs. (I don't think it matters for the header control): HD_ITEM hd_item = {0};
	Product: Xtreme Toolkit Pro version 13.2 (Unicode, static build) Platform: Windows 200x/XP/Vista/Win7 (32/64 bit) Language: Visual C++ 9.0 (Studio 2008)

scruzer Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 01 February 2008 Location: United States Status: Offline Points: 13	Post Options Post Reply Quote scruzer Report Post Thanks(0) Quote Reply Posted: 29 May 2008 at 2:21pm
	Or, perhaps -- using the default parameter leads to the bug in the code? virtual int AddColumn( LPCTSTR lpszColHeading, int nWidth = -1, int nFormat = LVCFMT_LEFT ); again, looking at this code. If you call this function the first time, with nWidth as the default parameter (-1)... The call to GetItem will request item "-1". int CXTListBase::AddColumn(LPCTSTR lpszColHeading, int nWidth/= -1/, int nFormat/= LVCFMT_LEFT/) { // if we are not in report mode return error. if ((GetWindowLong(m_pListCtrl->m_hWnd, GWL_STYLE) & LVS_TYPEMASK) != LVS_REPORT) return -1; // get a pointer to the header control, if NULL return error. CHeaderCtrl* pHeaderCtrl = _xtGetHeaderCtrl(); if (pHeaderCtrl == NULL) return -1; int iIndex = pHeaderCtrl->GetItemCount(); // could be 0! if (nWidth == -1 && iIndex >= 0 ) { // Get the column width of the previous column from header control HD_ITEM hd_item; hd_item.mask = HDI_WIDTH; //indicate that we want the width pHeaderCtrl->GetItem(iIndex - 1, &hd_item); nWidth = hd_item.cxy; } return m_pListCtrl->InsertColumn(iIndex, lpszColHeading, nFormat, nWidth, iIndex); } My fix, "don't use the default parameter".