如何从iOS中的UIDatePicker分配选定的日期

Question

- (void)viewDidLoad
{
 [super viewDidLoad];
 UIDatePicker *datepicker = [[UIDatePicker alloc] init];

 datepicker.datePickerMode = UIDatePickerModeDate;

 [datepicker addTarget:self action:@selector(date)   forControlEvents:UIControlEventValueChanged];

 self.birthDay.inputView = datepicker;
}


-(void)date
{

 NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

 [dateFormatter setDateStyle:NSDateFormatterMediumStyle];

 self.birthDay.text = [dateFormatter stringFromDate:[self.datepicker date]];
}

Answer 1

您已经在viewDidLoad方法中声明了UIDatePicker *datepicker ，因此作用域是本地的，要从其他功能使用它，请在.h文件中声明它

Answer 2

Try this,

in .h set datepicker as a property and in

- (void)viewDidLoad
{
   [super viewDidLoad];
   self.datepicker = [[UIDatePicker alloc] init];

   self.datepicker.datePickerMode = UIDatePickerModeDate;

   [self.datepicker addTarget:self action:@selector(date)   forControlEvents:UIControlEventValueChanged];

   self.birthDay.inputView = self.datepicker;
}

-(void)date
{
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc]init];
    dateFormat.locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];
    [dateFormat setDateFormat:@"yyyy-MM-dd"];
    dateString = [dateFormat stringFromDate:[self.datepicker date]];
    self.birthDay.text = dateString;
}