how to remain old image file in mvc c# -

im new .net.. start mvc c#..

i have problem here.. im trying update logo after insert it. if dont select image file, logo location (im store location part in db) come "null"..

here controller:

    public actionresult edit(payroll_company payroll_company)     {         if (modelstate.isvalid)         {             httppostedfilebase txtuploadfile = request.files["txtuploadfile"];              if (txtuploadfile != null && txtuploadfile.contentlength > 0)             {                 string logo = txtuploadfile.filename;                 payroll_company.comp_logo = logo;                  var path = path.combine(server.mappath("~/logo/"), logo);                 txtuploadfile.saveas(path);             }             else             {                 //payroll_company comp = db.payroll_company.find(payroll_company.comp_id);                 //payroll_company.comp_logo = comp.comp_logo;             }              db.entry(payroll_company).state = entitystate.modified;             db.savechanges();             return redirecttoaction("index");         }         return view(payroll_company);     } 

here view:

<div class="form-group">    <label class="control-label col-md-2">logo</label>     <div class="col-md-10">          <input type="file" name="txtuploadfile" id="txtuploadfile" class="form-control">     </div> </div> 

how can edit company information if dont select image file , remain old image?? hope out there can me solve this..

thanks in advance

var logopath = directory.getfiles(server.mappath("~/logo/")).orderbydescending(f => file.getcreationtime(f)).firstordefault(); if (!string.isnullorwhitespace(logopath)) {     payroll_company.comp_logo = path.getfilename(logopath); } 

add code else part,because need last image file,it means created laster other image files.otherwise,you need read db first,yes,you have it.

after answer,it seems payroll_company 1 property!,so why save it? need skip the save code,and leave the return code when there no image uploaded

your exception means object attched context,so must detach first,then attach again

var _dc = (iobjectcontextadapter)db; var _oc = _dc.objectcontext; var key;// = payroll_company.key; objectstateentry ose; if (_oc.objectstatemanager.trygetobjectstateentry(key, out ose)) {     var _entity = (payroll_company)ose.entity;     db.entry(_entity).state = entitystate.detached; } db.payroll_company.attach(payroll_company); db.entry(payroll_company).state = entitystate.modified;