展开TreeCtrl给定根的所有子节点

       //展开给定根的所有子节点
       void CMyTreeCtrl::ExpandAllItem(HTREEITEM hRoot, BOOL bExpand)
       {
              if (hRoot == NULL)
                     return;
 
              if (ItemHasChildren(hRoot))
              {  
                     Expand(hRoot,bExpand?TVE_EXPAND:TVE_COLLAPSE);
  
                     hRoot=GetChildItem(hRoot);  
                     while (hRoot!=NULL)
                     {
                            ExpandAllItem(hRoot, bExpand);
                            hRoot=GetNextSiblingItem(hRoot);
                     } // end of while(hRoot != NULL, Expand it and find next item)
              } // end of if(has children)
       }