'读XML到数据集
             Dim ds As new DataSet
             Dim ss As String
             ss = Path.GetFullPath("..") & "\XMLFile2.xml"
              ds.ReadXml(ss)
'**********************************************************************
          a1 = Path.GetFullPath("..") & "\XMLFile2.xml"
        Dim fsdata As FileStream = New FileStream(a1, FileMode.Create)
         '文件流
        ds.WriteXml(fsdata)
        fsdata.Close()
       '将ds写入文件XML