如何檢索月最後一個日期給月作爲參數在iphone

Question

我想檢索iphone應用程序中給定月份的最後日期。任何人都可以告訴我如何實現這一目標？我在stackoverflow上看到了一些解決方案，但他們只是給了最後一個月的一天。

謝謝。

UPDATE：

+(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; 

} 

如果我用這個代碼，它顯示我在控制檯輸出錯誤如下

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

Answer 1

你可以通過使用此功能： -

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]; 
    }