ios - Comparing uipickerdate to current date -

here code have 2 datepickers need compare them current date if condition or switch.

nsdateformatter *dateformatter = [[nsdateformatter alloc]init]; dateformatter.timezone=[nstimezone defaulttimezone]; dateformatter.timestyle=nsdateformattershortstyle; dateformatter.datestyle=nsdateformattershortstyle; nsstring *datetimestring=[dateformatter stringfromdate:starttime.date]; nslog(@"start time %@",datetimestring);   nsdateformatter *dateformatter2 = [[nsdateformatter alloc]init]; dateformatter2.timezone=[nstimezone defaulttimezone]; dateformatter2.timestyle=nsdateformattershortstyle; dateformatter2.datestyle=nsdateformattershortstyle; nsstring *datetimestring2=[dateformatter2 stringfromdate:endtime.date]; nslog(@"end time %@",datetimestring2); 

in .h

@property (weak, nonatomic) iboutlet uidatepicker *starttime; @property (weak, nonatomic) iboutlet uidatepicker *endtime; 

how do that? need store them nsdate or nstime since need time?

also, there if range in objective c?

thanks,

just add this:

if ([[nsdate date] isequaltodate:starttime.date]) { nslog(@"currentdate equal starttime");  }  if ([[nsdate date] isequaltodate:endtime.date]) { nslog(@"currentdate equal endtime");  } 

if want calculate interval between 2 dates use method

- (nstimeinterval)timeintervalsincedate:(nsdate *)anotherdate   if([starttime.date timeintervalsincedate:[nsdate date]] > 0) {   //start time greater today }  else if([starttime.date timeintervalsincedate:[nsdate date]] < 0) {     //start time less today }  else {    //both dates equal } 

for knowing when application has entered background use notifications add statement in viewdidload

[[nsnotificationcenter defaultcenter] addobserver:self selector:@selector(applicationenteredbackground) name:uiapplicationdidenterbackgroundnotification object:nil]; 

add function cater notification when posted

-(void)applicationenteredbackground {    //do above steps here when want. } 

and in dealloc function of class remove observer notification

-(void)dealloc {   [[nsnotificationcenter defaultcenter] removeobserver:self]; }