SampleApp.Form1.tvFilePlan_BeforeExpand Function
Called just before a tree view item is about to expand. Use this method to get the list of targets (children) for the selected component so that they may be displayed. The event is not triggered if the selected node has already had this event called upon it.

Private void tvFilePlan_BeforeExpand (object, System.Windows.Forms.TreeViewCancelEventArgs)
  Type Name Description  
    object sender    
    System.Windows.Forms.TreeViewCancelEventArgs e    
  Return Description  
    void