Finding an item (matching data instead of label)

FindItemData is another tree control searching function very similar to the FindItem function. Instead of matching a substring of the label, it compares the item's associated data. If an exact data match is found, the matching item is returned, otherwise NULL. This function uses the functions GetNextItem, GetPrevItem, and GetLastItem seen previously. In order to use this function, your tree control items must have associated data, which can be set using SetItemData. Also, the item's mask must include TVIF_PARAM.
// FindItemData  - Finds an item whose data matches the passed in lparam value.
// Returns       - Handle to the item or NULL
// lparam        - Data to search for
// bDownDir      - Search direction - TRUE for down
// hItem         - Item to start searching from. NULL for currently selected item

HTREEITEM CTreeCtrlX::FindItemData(DWORD lparam, BOOL bDownDir /*=TRUE*/, HTREEITEM hItem /*=NULL*/)
{
	HTREEITEM htiSel = hItem ? hItem : GetSelectedItem();
	HTREEITEM htiCur = bDownDir ? GetNextItem( htiSel ) :
	GetPrevItem( htiSel );
	if( htiCur == NULL )
	{
		if( bDownDir )
			htiCur = GetRootItem();
		else
			htiCur = GetLastItem( NULL );
	}
	while( htiCur && htiCur != htiSel )
	{
		DWORD sItemData = GetItemData( htiCur );
		if (sItemData == lparam )
			return htiCur;
		htiCur = bDownDir ? GetNextItem( htiCur ) : GetPrevItem( htiCur );
		if( htiCur == NULL )
		{
			if( bDownDir )
				htiCur = GetRootItem();
			else
				htiCur = GetLastItem( NULL );
		}
	}
	return NULL;
}



Comments

  • Same idea ... less code

    Posted by Legacy on 06/25/2002 12:00am

    Originally posted by: Shaun Cooley

    HTREEITEM CTreeCtrlEx::FindItemData(DWORD dwData, HTREEITEM hItem /* = TVI_ROOT */)
    
    {
    if(!hItem)
    return NULL;

    if(GetItemData(hItem) == dwData)
    return hItem;

    HTREEITEM hRet = NULL;
    HTREEITEM hChild = GetChild(hItem);
    if(hChild)
    hRet = FindItemData(dwData, hChild);

    if(hRet == NULL)
    {
    HTREEITEM hSibling = GetNextSibling(hItem);
    if(hSibling)
    hRet = FindItemData(dwData, hSibling);
    }

    return hRet;
    }

    Reply
  • Scanning a tree is very processor time expensive.

    Posted by Legacy on 01/22/1999 12:00am

    Originally posted by: Patrick Laplante

    This is not an efficient way to do it.
    Think about it.... the more item you got, the longer it will take.

    Use a CMap instead.
    CMap<HTREEITEM, HTREEITEM&, CMyData*, CMyData*> myMap;

    And look the help file on how to use it.

    Reply
Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • The open source cloud computing project OpenStack has come a long way since NASA and Rackspace launched it in 2010. Backed by leading technology infrastructure providers including Cisco, Dell, EMC, HP, IBM, Intel, and VMware, OpenStack underpins significant workloads at an increasingly diverse set of organizations, including BWM, CERN, Comcast, eBay, and Wal-Mart. For CIOs engaged in broader programs to win, serve, and retain customers -- and refocus business technology (BT) spend -- a planned and pragmatic …

  • Enterprises today must focus on digital transformation to remain competitive or disrupt their industries. The foundation for successful transformation is the adoption of a cloud-first mindset. However, IT organizations must first address legacy infrastructure and fragmented management tools that were not designed for the speed and flexibility of the cloud and digital era. Read this IDC Technology Spotlight paper to explore: Why digital transformation is driving a shift to a cloud-centric enterprise Key …

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date