calculating age from date picker

Question

hai i m trying to calcuating age from mvc annotaions date picker 

datatypes of DOB is datetime and age is in int .when i m trying to wrote like this i found a error like input sting is not in correct formate

 

my code is

public ActionResult AddTrainer(Tbl_Trainer _obj, HttpPostedFileBase file)

{

var thisyear = DateTime.Now.Year;

var birthyear = _obj.Dateofbirth;

// int age = (Int32.Parse(thisyear) - Int32.Parse(birthyear.ToString())) / 10000;

int age = (int)thisyear - int.Parse(_obj.Dateofbirth.Value.ToString())/1000;--input sting is not in correct formate

int outletid=(int) Session["id"];

if (file != null && file.ContentLength > 0)

{

BinaryReader br = new BinaryReader(file.InputStream);

var filename = Path.GetFileName(file.FileName);

int filelength = filename.Length;

byte[] filedata = br.ReadBytes((int)file.InputStream.Length);

int i = _Dalobj.AddTrainer(outletid,_obj, filedata, age);

if (i == 1)

 

{....

...}

 

TIA