NSDate 判断日期是今天还是昨天

-(NSString
*)compareDate:(NSDate *)date{

／／一：

NSCalendar
*cal = [NSCalendar currentCalendar];

NSDateComponents
*components = [cal components:(NSEraCalendarUnit|NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit) fromDate:[NSDate date]];

NSDate
*today = [cal dateFromComponents:components];

components
= [cal components:(NSEraCalendarUnit|NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit) fromDate:date];

NSDate
*otherDate = [cal dateFromComponents:components];

if([today
isEqualToDate:otherDate]) {

return
@"今天";

}

／／二；

NSDate
* today = [NSDate date];

NSDate
* yesterday = [NSDate dateWithTimeIntervalSinceNow:-86400];

NSDate
* refDate = date;

//
10 first characters of description is the calendar date:

NSString
* todayString = [[today description] substringToIndex:10];

NSString
* yesterdayString = [[yesterday description] substringToIndex:10];

NSString
* refDateString = [[refDate description] substringToIndex:10];

if
([refDateString isEqualToString:todayString])

{

return
@"今天";

}
else if ([refDateString isEqualToString:yesterdayString])

{

return
@"昨天";

}

else

{

return
[self formatDate:date];

}

}

-(NSString
*)formatDate:(NSDate *)date{

NSDateFormatter*
formatter = [[[NSDateFormatter alloc] init] autorelease];

[formatter
setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

//[formatter
setDateFormat:@"MM-ddHH:mm"];

NSString*
str = [formatter stringFromDate:date];

return
str;

}