在TreeCtrl控件中，加入了checkbox的风格。那当我在checkbox 中打勾时会引发什么消息呀

处理一下该控件的WM_LBUTTONDOWN消息，再用HitTest就可以知道用户选择了哪一项了。
example:
UINT   uFlags;
HTREEITEM   hItem   =   pmyTreeCtrl-> HitTest(myPoint,   &uFlags);

if   ((hItem   !=   NULL)   &&   (TVHT_ONITEM   &   uFlags))
{
      pmyTreeCtrl-> Select(hItem,   TVGN_CARET);
}
uFlags可以是:
TVHT_ABOVE     Above   the   client   area.    
TVHT_BELOW     Below   the   client   area.    
TVHT_NOWHERE     In   the   client   area,   but   below   the   last   item.    
TVHT_ONITEM     On   the   bitmap   or   label   associated   with   an   item.    
TVHT_ONITEMBUTTON     On   the   button   associated   with   an   item.    
TVHT_ONITEMICON     On   the   bitmap   associated   with   an   item.    
TVHT_ONITEMINDENT     In   the   indentation   associated   with   an   item.    
TVHT_ONITEMLABEL     On   the   label   (string)   associated   with   an   item.    
TVHT_ONITEMRIGHT     In   the   area   to   the   right   of   an   item.    
TVHT_ONITEMSTATEICON     On   the   state   icon   for   a   tree-view   item   that   is   in   a   user-defined   state.    
TVHT_TOLEFT     To   the   left   of   the   client   area.    
TVHT_TORIGHT     To   the   right   of   the   client   area