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

  • Enterprise cloud adoption has evolved rapidly from fringe curiosity to the mainstream. As enterprises increasingly move mission-critical workloads to the cloud, it's important to track best practices to ensure a seamless migration process. While CIOs are becoming increasingly mature and pragmatic in their approach to cloud, surprises and challenges still need to be addressed. Read this eBook to learn the key best practices for cloud deployment success, the importance of SLAs in choosing a cloud provider, and …

  • Old Habits Die Hard: The report, which is in its fifth year, polled 1,100 senior IT security executives at large enterprises around the world and indicates an ongoing disconnect between the security solutions organizations spend money on and the ability of those solutions to protect sensitive data. While 30 percent of respondents classify their organizations as 'very vulnerable' or 'extremely vulnerable' to data attacks (and the number of breaches continues to rise) the two top spending priorities are network …

Most Popular Programming Stories

More for Developers

RSS Feeds

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