判断TreeNode Click是在文字上还是在Checkbox上

selectedNode=treView.GetNodeAt(e.X,e.Y); 

 if(selectedNode!=null) 
 { 
 if(e.Button == MouseButtons.Left) 
 { 
 Rectangle rec = new Rectangle(selectedNode.Bounds.Left+16,selectedNode.Bounds.Top,selectedNode.Bounds.Width-16,selectedNode.Bounds.Height); 
 if (rec.Contains(e.X,e.Y)) 
 { 
 mouseMoveNode=selectedNode; 
 isMoveNode = true; 
 }