c# - convert string to mm/dd/yyyy datetime -

i'm trying convert string comes textbox, example in format '03/24/2014' datetime. i'm trying:

cultureinfo = new cultureinfo("en-us");                     dtassemblydate = datetime.parseexact(txtoperationsignaturedate.value, "dd/mm/yyyy", us); 

or

dtassemblydate = datetime.parseexact(txtoperationsignaturedate.value, "dd/mm/yyyy", null); 

but no luck , i'm getting exceptions value cannot casted datetime. how can fxi problem? in advance, laziale

if string expressed in format mm/dd/yyyy

cultureinfo = new cultureinfo("en-us");                     dtassemblydate = datetime.parseexact(txtoperationsignaturedate.value, "mm/dd/yyyy", us); 

but prefer use datetime.tryparse avoid surprises...

if(datetime.tryparse(txtoperationsignaturedate.value,                       cultureinfo.invariantculture,                       datetimestyles.none,                       out dtassemblydate))     console.writeline(dtassemblydate.toshortdatestring());