使用最近发现的内置单元，可以用一种更方便快捷的方式读写xml文件。

参考：http://wiki.freepascal.org/XML_Tutorial/zh_CN

uses

...

Laz2_DOM,laz2_XMLRead,laz2_XMLWrite

...

// 导出选中表
procedure TForm_data_outport.Button2Click(Sender: TObject);
var
  Doc: TXMLDocument;                                  // variable to document
  RootNode,TableNode,RecNode,FieldNode: TDOMNode;                    // variable to nodes
  i,iField: integer;
  sTblEn,sTblCn,sql,sFldName,sFldValue: string;
begin

  SaveDialog1.Filter:='XML格式文件(*.xml)';

  if SaveDialog1.Execute then
  begin
    fnXml := SaveDialog1.FileName;
    if pos('.XML',uppercase(fnXml)) > 0 then
      fnXml := stringreplace(fnXml,'.xml','',[rfIgnoreCase]);
  end;

  Doc := TXMLDocument.Create;

  // Create a root node
  RootNode := Doc.CreateElement('ROOT');
  Doc.Appendchild(RootNode);                           // save root node

  for i := 0 to cLBoxTblNameCn.Items.Count - 1 do
  begin
    if cLBoxTblNameCn.Checked[i] = true then
    begin
      sTblEn := LBoxTblNameEn.Items.Strings[i];
      sTblCn := cLBoxTblNameCn.Items.Strings[i];

      // 增加表
      TableNode := Doc.CreateElement('table');
      TDOMElement(TableNode).SetAttribute('name',sTblEn);
      TDOMElement(TableNode).SetAttribute('describ',sTblCn);
      RootNode.Appendchild(TableNode);

      sql := 'select * from ' + sTblEn;
      ZROQuery.Close;
      ZROQuery.sql.Clear;
      ZROQuery.sql.Add(sql);
      ZROQuery.Open;

      memo1.Append('表"'+sTblCn+'"导出记录数量：' + intToStr(ZROQuery.RecordCount));
      pBar.Max := ZROQuery.RecordCount;
      // 循环记录
      while not ZROQuery.EOF do
      begin
        pBar.Position:=ZROQuery.RecNo;

        RecNode := Doc.CreateElement('record');
        TableNode.Appendchild(RecNode);

        // 循环字段
        for iField := 0 to ZROQuery.FieldCount - 1 do
        begin
          FieldNode := Doc.CreateElement('field');
          sFldName := ZROQuery.Fields[iField].FieldName;
          sFldValue := ZROQuery.Fields[iField].AsString;
          TDOMElement(FieldNode).SetAttribute(sFldName,sFldValue);
          //TDOMElement(FieldNode).
          RecNode.Appendchild(FieldNode);
        end;

        ZROQuery.Next;
      end;

      pBar.Position:=0;
    end;
  end;

  writeXMLFile(Doc,(fnXml + '.xml'));                     // write to XML
  Doc.Free;

end;