写入到excel?

Question

写入到excel
Excel.Application ExcelApp=new Excel.ApplicationClass();
Excel.Workbook ExcelWorkBook=ExcelApp.Application.Workbooks.Add(true);
Excel.Worksheet ExcelWorkSheet=(Excel.Worksheet)ExcelWorkBook.Worksheets[1];for ( ii=0;ii<rowcount;ii++)
{
for ( jj=0;jj<columncount;jj++)
{ ExcelApp.Cells[ii+4,jj+1]=ds.Tables["tablevalue"].Rows[ii][jj].ToString().Trim(); }
}
ExcelWorkBook.SaveCopyAs(pathsave);
ExcelWorkSheet=null;
ExcelWorkBook.Close(false,null,null);
ExcelApp.Quit();