【实战】如何实现滚轮时间的显示

(高级控件）拾取器

PS：无论是UIPickerView还是UIDatePicker，都需要设置成IBOutlet类型。

按钮的事件类型为：Touch Up Inside

- （IBAction）buttonPressed:(id)sender{

  NSDate *selectedTime = [UIDatePicker date];

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

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

  NSString *selectedTimeString = [dateFormatter stringFromDate:selectedTime];

  NSString *message = [[NSString alloc]initWithFormat:@"The date and time you selected is: %@",selectedTimeString];

  UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"shijian" message:message

                                                                    delegate:nil  cancelButtonTitle:@"Cancel" otherButtonTitles:nil];

  [alertView show]; 

}

-(void)viewDidLoad{

  [super viewDidLoad];

  NSDate *now = [NSDate date];

  [datePicker setDate:now animated:NO]; //设定日期拾取器的时间，animated:YES是实现动画效果，在初始化时候滚轮滚动到当前日期。

}