在Delphi6.0下生成Excel文件，请高手解答！！急！！！特急！！！！！(100)

Question

有以下生成Excel文件的程序，在Delphi5下运行正常，但是在Delphi6.0下提示
null不是“OLEVariant”类型不匹配，ExcelApplication1.Workbooks.Add(null,0);这行通不过。
请高手指点！！！为什么？？？？
procedure TForm_Format.BitBExcelClick(Sender: TObject);
  var
    i,row:integer;
    ExcelApplication1: TExcelApplication;
    ExcelWorkbook1: TExcelWorkbook;
    ExcelWorksheet1: TExcelWorksheet;
    ExcelFileName:String;
begin
    if SaveDialogExcel.Execute then
    begin
      ExcelApplication1:=TExcelApplication.Create(self);
      ExcelWorkbook1:=TExcelWorkbook.Create(self);
      ExcelWorksheet1:=TExcelWorksheet.Create(self);
      Screen.Cursor:=crHourGlass;
      ExcelApplication1.Connect;
      ExcelApplication1.Workbooks.Add(null,0); //..该行不能通过！！！！
      ExcelWorkBook1.ConnectTo(ExcelApplication1.Workbooks[1]);
      ExcelWorkSheet1.ConnectTo(ExcelWorkBook1.Sheets[1] as _WorkSheet);
      ExcelFileName:=SaveDialogExcel.FileName;
      ExcelWOrkSheet1.Cells.Item[1,1]:='楼宇名称';
      ExcelWOrkSheet1.Cells.Item[1,2]:='门牌号码';
      ExcelWOrkSheet1.Cells.Item[1,3]:='计量表名称';
      ExcelWOrkSheet1.Cells.Item[1,4]:='设备序号';
      ExcelWOrkSheet1.Cells.Item[1,5]:='读  数';
      ExcelWOrkSheet1.Cells.Item[1,6]:='计量单位';
      ExcelWOrkSheet1.Cells.Item[1,7]:='抄表日期';
      ExcelWOrkSheet1.Cells.Item[1,8]:='抄表时间';
      QueryHisData.First;
      row:=2;
      While not QueryHisData.Eof do
      begin
          ExcelWOrkSheet1.Cells.Item[row,1]:=QueryHisData.FieldByname('BldName').AsString;
          ExcelWOrkSheet1.Cells.Item[row,2]:=QueryHisData.FieldbyName('DoorPlate').AsString;
          ExcelWOrkSheet1.Cells.Item[row,3]:=QueryHisData.FieldbyName('EquipName').AsString;
          ExcelWOrkSheet1.Cells.Item[row,4]:=QueryHisData.FieldbyName('EquipNo').AsString;
          ExcelWOrkSheet1.Cells.Item[row,5]:=QueryHisData.FieldbyName('PracticeData').AsString;
          ExcelWOrkSheet1.Cells.Item[row,6]:=QueryHisData.FieldbyName('EquipMete').AsString;
          ExcelWOrkSheet1.Cells.Item[row,7]:=QueryHisData.FieldbyName('GDate').AsString;
          ExcelWOrkSheet1.Cells.Item[row,8]:=QueryHisData.FieldbyName('GTime').AsString;
          row:=row+1;
          QueryHisData.next;
      end;
      ExcelWorkBook1.SaveCopyAs(ExcelFileName+'.xls');
      ExcelWOrkBook1.Close(false);
      ExcelApplication1.Disconnect;
      ExcelApplication1.Quit;
      Screen.Cursor:=crDefault;
    end;end;

Answer 1

ExcelApplication1:=TExcelApplication.Create(self);
      ExcelWorkbook1:=TExcelWorkbook.Create(self);
      ExcelWorksheet1:=TExcelWorksheet.Create(self);
      这三行去掉。

Answer 2

同意，ycxuyuq(注册失败) ,我在转换到d6时也遇到过这样的问题。
解决办法相同！！

Answer 3

谢谢ycxuyuq(注册失败) 
问题解决了，怎么给你加分啊？？！！

Answer 4

I no tiem 了，我这有一段在DELPHI6中能运行的代码，去看看能否解决
procedure Tfrm_main.sb_excelClick(Sender: TObject);
var
   Unassigned: Variant;
   ls_xlsFilename:string;
   eclApp,WorkBook :variant;
   li_fieldcount,li_rec,i,j,li_c :integer;
begin
   if (DBGrid_EditTableForm.DataSource.DataSet.State=dsInactive) then exit;
   li_rec:=DBGrid_EditTableForm.DataSource.DataSet.RecordCount;
   if (li_rec<1) then exit;
   li_fieldcount :=DBGrid_EditTableForm.FieldCount;
   ls_xlsFilename :=DBText1.Field.AsString+'表结构.xls';
   try
     frm_progress.Show;
     frm_progress.Caption:='正在检查系统是否MS EXCEL';
     eclApp :=CreateOleObject('Excel.Application');
     WorkBook :=CreateOleObject('Excel.Sheet');
   except
     frm_progress.Close;
     MessageDlg('您的系统没有安装MS EXCE!', mtInformation,[mbOk],0);
     exit;
   end;   try
     frm_progress.Caption:='正在构造表结构标题';
     WorkBook :=eclApp.workBooks.add;
     eclApp.cells(1,li_fieldcount div 2) :=DBText1.Field.AsString+'表结构';
     //eclApp.cells(2,1) :='字段名中文含义';
     //eclApp.cells(3,1) :='字    段    名';
     frm_progress.progressbar1.Position:=0;
     frm_progress.progressbar1.Max:=li_fieldcount;
     for i :=1 to  li_fieldcount do      //转化字段名；
     begin
       frm_progress.Caption:='正在构造字段信息......';
       frm_progress.progressbar1.Position:=i;
       eclApp.cells(2,i) :=DBGrid_EditTableForm.Columns[i-1].Title.caption ;
       eclApp.cells(3,i) :=DBGrid_EditTableForm.Fields[i-1].FieldName ;
     end;
     DBGrid_EditTableForm.DataSource.DataSet.First ;
     frm_progress.progressbar1.Position:=0;
     frm_progress.progressbar1.Max:=li_rec*li_fieldcount;
     for i :=1 to  li_rec  do    //recordcount
     begin
       for j :=1 to  li_fieldcount do  //转化一个记录
       begin
         li_c:=li_c+1;
         frm_progress.Caption:='正在构造表结构内容信息......';
         frm_progress.progressbar1.Position:=li_c;
         eclApp.cells(i+3,j) :=DBGrid_EditTableForm.Fields[j-1].AsString;
       end;
       DBGrid_EditTableForm.DataSource.DataSet.Next ;
     end;
     frm_progress.Close;
     try
       WorkBook.saveas(ExtractFilePath(Application.ExeName )+ls_xlsFilename);
       WorkBook.close;
       showmessage('保存EXECL文件成功，路径为：'+ExtractFilePath(Application.ExeName )+ls_xlsFilename);
     except
       MessageDlg('保存文件出错!', mterror,[mbOk],0);
     end;
   except
     frm_progress.Close;
     showmessage('不能正确操作EXECL文件，可能该文件已经被其他程序占用或系统错误');
     WorkBook.close;
     eclApp.quit;
     eclApp :=Unassigned;
   end;
end;