判断是否包含某个节点
Dim xml As String = "<xml><to>George</to><from>John</from><content>Don't forget the meeting!</content></xml>"
Dim xo As Foxtable.XObject = Foxtable.XObject.Parse(xml)
if xo("to") isnot nothing then
Output.Show(xo("to"))
end if
if xo("to2") isnot nothing then
Output.Show(xo("to2"))
end if