asp.net - Need to get ArrayList() to Export to Excel -

i having trouble exporting data excel. application uses arraylist() house data. don't understand arraylist's. inside arraylist() mydataclass, val1, val2, etc...the array has 7 columns , can have anywhere 1 300 rows of data. when this, can't seem down val1 data, excel sheet in cell a1 saying, mydataclass. can please me this, thank in advance. on visual studio 2010 , office 2010.

protected sub btnexport_click_backup(sender object, e system.eventargs) handles btnexport.click      dim itemlist new arraylist()     itemlist = session("sessitemlist2")     itemlist.reverse()       dim dt new system.data.datatable()     dt.columns.add("serlnmbr")     dt.columns.add("itemnmbr")     dt.columns.add("locncode")     dt.columns.add("status")     dt.columns.add("msl")     dt.columns.add("invoicenumber")     dt.columns.add("activationstatus") 

' doing wrong...

    integer = 0 itemlist.count - 1          dim dr datarow          dr = dt.newrow          dr.item(0) = itemlist(0).val1.tostring          dt.rows.add(dr)      next      try         dim oexcel interop.excel.application         dim obook workbook         dim osheet worksheet         oexcel = createobject("excel.application")         obook = oexcel.workbooks.add(type.missing)         osheet = obook.worksheets(1)          dim misvalue object = system.reflection.missing.value         dim integer         dim j integer         dim dc system.data.datacolumn         dim dr system.data.datarow         dim colindex integer = 0         dim rowindex integer = 0          'export columns excel file         each dc in dt.columns             colindex = colindex + 1             osheet.cells(1, colindex) = dc.columnname         next          'export rows excel file         each dr in dt.rows             rowindex = rowindex + 1             colindex = 0             each dc in dt.columns                 colindex = colindex + 1                 osheet.cells(rowindex + 1, colindex) = dr(dc.columnname)             next         next          'set final path         dim filename string = "c:\temp\exportedfile" + ".xls"         dim finalpath = filename         osheet.columns.autofit()         'save file in final path         obook.saveas(finalpath, xlfileformat.xlworkbooknormal, type.missing, type.missing, type.missing, type.missing, xlsaveasaccessmode.xlexclusive, type.missing, type.missing, type.missing, type.missing, type.missing)            'release objects         releaseobject(osheet)         obook.close(false, type.missing, type.missing)         releaseobject(obook)         oexcel.quit()         releaseobject(oexcel)         'some time office application not quit after automation: calling gc.collect method.         gc.collect()           '  open file user         dim oxcel interop.excel.application         dim owb workbook         dim osht worksheet         dim ocell range          oxcel = new interop.excel.application         oxcel.visible = true          ' cpu errors out here becz office not registered, can go excel & remove registration msgbox press continue         owb = oxcel.workbooks.open(finalpath)         osht = owb.worksheets(1)         ocell = osht.range("a1")     catch ex exception         '  messagebox.show(ex.message, "warning", messageboxbuttons.ok)         '  need error     end try  end sub 

' here small portion of mydataclass

public class mydataclass

public sub new(byval v1 string, byval v2 string, byval v3 string, byval v4 string, optional byval v5 string = "", optional byval v6 string = "", optional byval v7 string = "", optional byval v8 string = "")     val1 = v1     val2 = v2     val3 = v3     val4 = v4     val5 = v5     val6 = v6     val7 = v7     val8 = v8 end sub public property val1() string             return _val1     end     set(byval value string)         _val1 = value     end set end property 

etc...

public _val1 string public _val2 string public _val3 string public _val4 string public _val5 string public _val6 string public _val7 string public _val8 string 

end class

an arraylist list of objects. there no .val property on it. there may object there val property, first have cast it.

you didn't show how make arraylist, or contains have guess.

if have class val1 property, have cast object type before can access val1

dr.item(0) = cast(itemlist(0),myclass).val1.tostring 

since arraylist takes object, have cast them appropriate type first. or, if needs strings can call tostring on simple types integers.

fyi, if working excel in .net application understand need excel on server. won't have permissions access default , microsoft has recommended against doing on decade. there third-party .net components designed work various office file formats without requiring office installed. threading model of office apps wrong being used in web environment.