c# - Shouldn't the column start with special characters? -

i'm working excel sheet of .xls format , writing data it. problem whenever data doesn't start alphabets prompting me different errors.

for example: when column data started =?us-ascii?q?google keywords?= threw me exception:

 exception hresult: 0x800a03ec   

and when data -------- original message --------subject: error was:

not enough storage available complete operation. (exception hresult: 0x8007000e (e_outofmemory)) 

this how i'm writing data:

 foreach (allcasesreplies infolist in allcasesreplies)   {       n = 0;       mworksheet.cells[l + m, ++n] = infolist.id;       mworksheet.cells[l + m, ++n] = infolist.replies;       m++;    } 

this how clean objects:

private static void saveandcollectthegarbage(microsoft.office.interop.excel.application excelapp, string path, microsoft.office.interop.excel.sheets sheet) {         excelapp.columns.autofit();         mworkbook.saveas(path, microsoft.office.interop.excel.xlfileformat.xlworkbooknormal,         missing.value, missing.value, missing.value, missing.value, microsoft.office.interop.excel.xlsaveasaccessmode.xlexclusive,         missing.value, missing.value, missing.value,         missing.value, missing.value);         mworkbook.close(true, missing.value, missing.value);         sheet = null;         mworkbook = null;         excelapplication.quit();         gc.waitforpendingfinalizers();         gc.collect();         gc.waitforpendingfinalizers();         gc.collect(); } 

so have tried omitting these data , working great.

are there rules column has start specific characters , if so, these?

if type "?" in excel cell has general format, excel automaticall interprete formula. need change cell format before inserting text cell.

something like:

foreach (allcasesreplies infolist in allcasesreplies)   {       n = 0;       microsoft.office.interop.excel.range range1 = mworksheet.cells[l + m, ++n] range;       range1.numberformat = "@";       range1.value2 = infolist.id;        microsoft.office.interop.excel.range range2 = mworksheet.cells[l + m, ++n] range;       range2.numberformat = "@";       range2.value2 = infolist.replies;        m++;    }