string strFileName = Environment.CurrentDirectory+@"/template/template.tpl";
    string strSaveFileName = Environment.CurrentDirectory+@"/excel/"+System.DateTime.Now.ToString().Replace(":","").Replace("-","").Replace(" ","")+@".xls";
    Excel.Application ThisApplication = new Excel.ApplicationClass();
    Excel.Workbook ThisWorkBook;
    object missing = System.Reflection.Missing.Value;
    try
    {
     //加载Excel模板文件
     ThisWorkBook = ThisApplication.Workbooks.Open(strFileName,missing,missing,missing,missing,missing,missing,missing,missing,missing,missing,missing,missing);
     Excel.Worksheet ThisSheet = (Excel.Worksheet)ThisWorkBook.Sheets[1];
     ThisSheet.Cells[7,1] = dtEnd.ToShortDateString();
     progressBar.Value = 30;
     ThisApplication.Visible = false;
     DataRow dr = dt.Rows[0];
     for( int i=0; i<dt.Columns.Count;i++)
     {
      ThisSheet.Cells[7,i+2] = dr[i].ToString();
      progressBar.Value +=1;
     }
     //更新数据后另存为新文件
     ThisSheet.SaveAs(strSaveFileName,missing,missing,missing,missing,missing,missing,missing,missing);
    }
    catch{}
    finally
    {
     ThisApplication.Quit();
     ThisWorkBook = null;
     ThisApplication = null;
     //dt = null;
    }
    try
    { //打开刚才生成的Excel文件
     Excel.Workbook NewWorkBook;
     NewWorkBook = NewApplication.Workbooks.Open(strSaveFileName,missing,missing,missing,missing,missing,missing,missing,missing,missing,missing,missing,missing);
     Excel.Worksheet NewSheet = (Excel.Worksheet)NewWorkBook.Sheets[1];
     NewApplication.Visible = true;

//也可以使用System.Diagnostics.Process.Start(strSaveFileName);来打开新文件

    }