日期转换为字符串xcode

Question

我正在开发一个显示开始日期和结束日期的应用，但我在文本字段中显示日期问题

这里的一切正常：

但是当我在2012年12月30日的输出中你可以看到2012年（硬编码），但是在textfield中它写了2013年（格式化）：

如果我尝试使用＆＃34，那么

会发生同样的事情。整天＆＃34;选项：

要分享我的应用代码，以便让事情变得更轻松

#import "StartEndEventVC.h"
#import "visitVC.h"
#import "Functions.h"



@interface StartEndEventVC ()
{
    NSDate                  *date;
    NSDateFormatter         *df;
    NSString                *selectedCell;
}

@property (nonatomic, strong) Functions *funciones;
@end


@implementation StartEndEventVC

@synthesize funciones       = _funciones;
@synthesize datePicker      = _datePicker,
            SwitchDate      = _SwitchDate,
            fecFinDateSE    = _fecFinDateSE,
            fecInicioDateSE = _fecInicioDateSE;


#pragma mark *** Common methods ***
- (void)viewDidLoad
{
    [super viewDidLoad];

    //Datepicker initial settings
    self.datePicker.timeZone = [NSTimeZone localTimeZone];
    self.datePicker.locale   = [NSLocale currentLocale];
    self.datePicker.calendar = [NSCalendar currentCalendar];

    //Date format initial settings
     df             = [NSDateFormatter new];
    [df setDateFormat:@"EE, dd MMM YYYY HH:mm a"];
    [df setTimeZone:[NSTimeZone localTimeZone]];

    //initial cell to interact with datepicker
    selectedCell    = @"startDate";


    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"back"
                                                                             style:UIBarButtonItemStyleBordered
                                                                            target:self
                                                                           action:@selector(didBack:)];
}


-(void)estableceFechaCamposTexto{

    self.fecInicioDateSE        = [[NSDate alloc]init];
    self.fecFinDateSE           = [[NSDate alloc]init];

    self.fecInicioDateSE        = [NSDate date];
    self.fecFinDateSE           = [self.fecInicioDateSE dateByAddingTimeInterval:60*60];


    self.startDateLabel.text    = [df stringFromDate:self.fecInicioDateSE];
    self.endDateLabel.text      = [df stringFromDate:self.fecFinDateSE];
}


-(void)viewDidAppear:(BOOL)animated{
    if ((self.fecInicioDateSE == nil) || (self.fecFinDateSE == nil)) [self estableceFechaCamposTexto];

        self.startDateLabel.text    = [df stringFromDate:self.fecInicioDateSE];
        self.endDateLabel.text      = [df stringFromDate:self.fecFinDateSE];
}




-(Functions *)funciones{
    if (!_funciones) _funciones = [[Functions alloc]init];
    return _funciones;
}


-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
    if ([segue.identifier isEqualToString:@"doneStartEnd"]) {

        [segue.destinationViewController setFecInicioDateV:  self.fecInicioDateSE];
        [segue.destinationViewController setFecFinDateV:     self.fecFinDateSE];

        NSLog(@"fecha inicio StartEvent: %@", self.fecInicioDateSE);
        NSLog(@"fecha fin    StartEvent: %@", self.fecFinDateSE);

    }
}

#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    switch (indexPath.row) {
        case 0:
            selectedCell = @"startDate";
            self.datePicker.date = self.fecInicioDateSE;

            break;
        case 1:
            selectedCell = @"endDate";
            self.datePicker.date = self.fecFinDateSE;
        default:
            break;
    }
}
#pragma mark -


#pragma mark *** Custom methods ***
-(void)comparaFechaInicio{

    if ([self.fecInicioDateSE timeIntervalSinceDate:self.fecFinDateSE] >= 0) {
        if (self.SwitchDate.on)     self.fecFinDateSE = [self.fecInicioDateSE dateByAddingTimeInterval:60*60*24];
        else
            if(!(self.SwitchDate.on))   self.fecFinDateSE = [self.fecInicioDateSE dateByAddingTimeInterval:60*60];
    }

    self.startDateLabel.text    = [df stringFromDate:self.fecInicioDateSE];
    self.endDateLabel.text      = [df stringFromDate:self.fecFinDateSE];

    NSLog(@"Hardcoded date: %@", self.fecInicioDateSE);
    NSLog(@"formatted date: %@", [df stringFromDate:self.fecFinDateSE]);
}

- (void) didBack:(id)sender {
    [self.navigationController popViewControllerAnimated:YES];
}

#pragma mark -


#pragma mark *** Button actions ***
-(IBAction)adjustDate:(id)sender{
    if ([selectedCell isEqualToString:@"startDate"]){

        self.fecInicioDateSE = [self.datePicker date];
        [self comparaFechaInicio];
    }
    else
        if ([selectedCell isEqualToString:@"endDate"]){

            self.fecFinDateSE = [self.datePicker date];
            self.endDateLabel.text  = [df stringFromDate:self.datePicker.date];
        }
}

- (IBAction)saveChanges:(id)sender {
    [self comparaFechaInicio];

    [self performSegueWithIdentifier:@"doneStartEnd" sender:self];
}

-(IBAction)changeDateType:(id)sender{
    if (self.SwitchDate.on){
        self.datePicker.datePickerMode  = UIDatePickerModeDate;
        [df setDateFormat:@"EE, dd MMM YYYY"];
    }
    else{
        self.datePicker.datePickerMode  = UIDatePickerModeDateAndTime;
        [df setDateFormat: @"EE, dd MMM YYYY HH:mm a"];
    }

    [self comparaFechaInicio];
}
#pragma mark -
@end

Answer 1

你陷入Apple did with recent their Do Not Disturb bug的陷阱。您希望在NSDateFormatter中使用yyyy，而不是YYYY。