private mySB as new StringBuilder
Sub Recursive(byval ParentID as Int) 　
    dim query= from c in mylist 
        where ParentID=ParentID 

    for each item in query 
        mysb.appendstring(getHTML(item))

       ' 这个负责递归所有的子孙。
        Recursive(Item.id) 
    next 
end sub        

stringBuilder mySB;

void recursive (int ParentID)
{
    var query= from c in mylist
                      where c.ParentID=ParentID
                      select c.ID, c.ParentID, c.Title

     for each item in query
     {
          mySB.appendText("<TD>" + item.Title + "</TD>");
           
          ///递归调用，渲染子孙树
          recursive(item.ID);
     }      
}