iOS开发技巧

(Swift)

import UIKit

class ViewController: UIViewController {
    var datePicker: UIDatePicker!
    
    func datePickerDateChanged(datePicker: UIDatePicker) {
        println("Selected date = (datePicker.date)")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        datePicker = UIDatePicker()
        datePicker.center = view.center
        view.addSubview(datePicker)
        
        datePicker.addTarget(self,
            action: "datePickerDateChanged:",
            forControlEvents: .ValueChanged)
            
        /*
            set the minimum and the maximum dates that it can display
        */
        
        let oneYearTime:NSTimeInterval = 365 * 24 * 60 * 60
        let todayDate = NSDate()
        let oneYearFromToday = todayDate.dateByAddingTimeInterval(oneYearTime)
        let twoYearsFromToday = todayDate.dateByAddingTimeInterval(2 * oneYearTime)
        datePicker.minimumDate = oneYearFromToday
        datePicker.maximumDate = twoYearsFromToday
    }
}

(Objective-C)

#import "ViewController.h"

@interface ViewController ()

@property (nonatomic, strong) UIDatePicker *myDatePicker;

@end

@implementation ViewController

- (void) datePickerDateChanged:(UIDatePicker *)paramDatePicker {
    if ([paramDatePicker isEqual:self.myDatePicker]) {
        NSLog(@"Selected date = %@", paramDatePicker.date);
    }
}

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.myDatePicker = [[UIDatePicker alloc] init];
    self.myDatePicker.center = self.view.center;
    [self.view addSubview:self.myDatePicker];
    
    [self.myDatePicker addTarget:self
        action:@selector(datePickerDateChanged:)
        forControlEvents:UIControlEventValueChanged];
        
    NSTimeInterval oneYearTime = 365 * 24 * 60 * 60;
    NSDate *todayDate = [NSDate date];
    NSDate *oneYearFromToday = [todayDate dateByAddingTimeInterval:oneYearTime];
    NSDate *twoYearsFromToday = [todayDate dateByAddingTimeInterval:2 * oneYearTime];
    self.myDatePicker.minimumDate = oneYearFromToday;
    self.myDatePicker.maximumDate = twoYearsFromToday;
}

@end