#import "ViewController.h"
  2 
  3 @interface ViewController ()
  4 @property (weak, nonatomic) IBOutlet UIPickerView *pickerView;
  5 
  6 @end
  7 
  8 @implementation ViewController
  9 
 10 - (void)viewDidLoad
 11 {
 12     [super viewDidLoad];
 13     //初始化資料
 14     NSMutableArray *multYears = [NSMutableArray array];//
 
年
 15     for(int i=0; i<20; i++)
 16     {
 17         NSString *year = [NSString stringWithFormat:@"20%02d年",i+1];
 18         [multYears addObject:year];
 19     }
 20     self.years = multYears;
 21     
 22     NSMutableArray *multMonths = [NSMutableArray arrayWithCapacity:12];//月
 23     for
 
(int i=1; i<=12; i++)
 24     {
 25         NSString *month = [NSString stringWithFormat:@"%d月",i];
 26         [multMonths addObject:month];
 27     }
 28     self.months = multMonths;
 29     
 30     NSMutableArray *multDays = [NSMutableArray arrayWithCapacity:31];//日
 31     for(int i=1; i<=31
 
; i++)
 32     {
 33         NSString *day = [NSString stringWithFormat:@"%d日",i];
 34         [multDays addObject:day];
 35     }
 36     self.days = multDays;
 37     
 38     
 39     //設定pickerView的資料來源和代理
 40     self.pickerView.dataSource = self;
 41     self.pickerView.delegate = self;
 42     
 43     //顯示當前日期
 44     NSDate *now = [NSDate date];
 45     //分解日期
 46     NSCalendar  *calendar = [[NSCalendar alloc]initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
 47     
 48     NSCalendarUnit unitFlags = NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay;
 49     NSDateComponents *components = [calendar components:unitFlags fromDate:now];
 50     
 51     
 52     //設定pickerView顯示當前日期
 53     NSInteger year = [components year];
 54     [self.pickerView selectRow:year-2000-1 inComponent:0 animated:year];
 55     
 56     NSInteger month = [components month];
 57     [self.pickerView selectRow:month-1 inComponent:1 animated:month];
 58     
 59     NSInteger day = [components day];
 60     [self.pickerView selectRow:day-1 inComponent:2 animated:day];
 61 }
 62 
 63 #pragma mark - pickerView的代理方法
 64 -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
 65 {
 66     return 3;
 67 }
 68 -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
 69 {
 70     NSInteger row = 0;
 71     switch (component)
 72     {
 73         case 0:
 74             row = self.years.count;
 75             break;
 76         case 1:
 77             row = self.months.count;
 78             break;
 79         case 2:
 80             row = self.days.count;
 81             break;
 82     }
 83     return  row;
 84 }
 85 
 86 -(NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
 87 {
 88     NSString *title;
 89     switch (component)
 90     {
 91         case 0:
 92             title = self.years[row];
 93             break;
 94         case 1:
 95             title = self.months[row];
 96             break;
 97         case 2:
 98             title = self.days[row];
 99             break;
100     }
101     return  title;
102 }
103 -(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
104 {
105     NSString *strDate = [NSString stringWithFormat:@"%@-%@-%@",
106                          self.years[[pickerView selectedRowInComponent:0]],
107                          self.months[[pickerView selectedRowInComponent:1]],
108                          self.days[[pickerView selectedRowInComponent:2]]];
109     NSLog(@"%@",strDate);
110 }
111 @end