如何回溯月份的最后一个月在iphone中给出月份作为参数

我想在iPhone应用程序中检索给定月份的最后日期。 任何人都可以告诉我如何实现这一目标？ 我在stackoverflow上看到了一些解决方案，但它们只给出了一个月的最后一天。

谢谢。

更新：

+(NSString*)getLastDateOfMonth:(NSString *)monthYearString { //NSString *inputDate = [NSString stringWithFormat:@"%@ %@",@"01",monthYearString]; NSString *inputDate = [NSString stringWithFormat:@"%@ %@",@"01",@"May 2012"]; NSLog(@"Input date:- %@",inputDate); NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init]; [dateFormatter setDateFormat:@"dd MMM yyyy"]; NSDate *date = [dateFormatter dateFromString:inputDate]; NSCalendar *gregCalendar=[[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease]; NSDateComponents *components=[gregCalendar components:NSMonthCalendarUnit|NSYearCalendarUnit fromDate:date]; NSInteger month=[components month]; NSInteger year=[components year]; if (month==12) { [components setYear:year+1]; [components setMonth:1]; } else { [components setMonth:month+1]; } [components setDay:1]; NSDate *lastDate = [[gregCalendar dateFromComponents:components] dateByAddingTimeInterval:0]; NSDateFormatter *outputFormatter = [[NSDateFormatter alloc]init]; [outputFormatter setDateFormat:@"MM/dd/yyyy"]; NSString *lastDateOfMonth = [outputFormatter stringFromDate:lastDate]; return lastDateOfMonth; } 

如果我使用此代码，它会在控制台中显示错误输出，如下所示

  Input date:- 01 May 2012 LAst DAte in Month:- 06/01/2012 

Answer 1

您可以使用此function执行此操作： –

  NSDate currDate=[NSDate date]; NSDate *getLastDateMonth(NSDate *currDate) { NSCalendar *gregCalendar=[[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease]; NSDateComponents *components=[gregCalendar components:NSMonthCalendarUnit|NSYearCalendarUnit fromDate:currDate]; NSInteger month=[components month]; NSInteger year=[components year]; if (month==12) { [components setYear:year+1]; [components setMonth:1]; } else { [components setMonth:month+1]; } [components setDay:1]; return [[gregCalendar dateFromComponents:components] dateByAddingTimeInterval:0]; }