1 前言
UIDatePicker是一個十分類似於UIPickerView的類，十分常用，今天我們來學習一下。

2 UIDatePicker簡介
上代碼
日期選擇：
.h文件：
[plain]
@property(nonatomic,strong) UIDatePicker *myDatePicker; 

@property(nonatomic,strong) UIDatePicker *myDatePicker;
.m文件：
[plain]
@synthesize myDatePicker; 
 
- (void)viewDidLoad 
{ 
    //一年的秒數 
    float oneYearTime = 60*60*24*365; 
    NSLog(@"oneYearTime====>%f",oneYearTime); 
    [super viewDidLoad]; 
    // Do any additional setup after loading the view, typically from a nib. 
    self.view.backgroundColor = [UIColor whiteColor]; 
    //事件選擇器 
    self.myDatePicker = [[UIDatePicker alloc] init]; 
    self.myDatePicker.center = self.view.center; 
    self.myDatePicker.datePickerMode=UIDatePickerModeDate; 
    //添加事件 
    [self.myDatePicker addTarget:self action:@selector(datePickerDateChanged:) forControlEvents:UIControlEventValueChanged]; 
    //獲得當前時間 
    NSDate *currentDate = self.myDatePicker.date; 
    NSLog(@"Date = %@",currentDate); 
    NSDate *oneYearFromToday = [currentDate dateByAddingTimeInterval:oneYearTime]; 
    NSDate *twoYearFromToday = [currentDate dateByAddingTimeInterval:2*oneYearTime]; 
    //最小可選時間 
    self.myDatePicker.minimumDate = oneYearFromToday; 
    self.myDatePicker.maximumDate = twoYearFromToday; 
    [self.view addSubview:self.myDatePicker]; 
} 
 
-(void) datePickerDateChanged:(UIDatePicker *)paramDatePicker{ 
    if ([paramDatePicker isEqual:self.myDatePicker]) { 
        NSLog(@"Selected date=%@",paramDatePicker); 
    } 
} 

@synthesize myDatePicker;

- (void)viewDidLoad
{
    //一年的秒數
    float oneYearTime = 60*60*24*365;
    NSLog(@"oneYearTime====>%f",oneYearTime);
    [super viewDidLoad];
 // Do any additional setup after loading the view, typically from a nib.
    self.view.backgroundColor = [UIColor whiteColor];
    //事件選擇器
    self.myDatePicker = [[UIDatePicker alloc] init];
    self.myDatePicker.center = self.view.center;
    self.myDatePicker.datePickerMode=UIDatePickerModeDate;
    //添加事件
    [self.myDatePicker addTarget:self action:@selector(datePickerDateChanged:) forControlEvents:UIControlEventValueChanged];
    //獲得當前時間
    NSDate *currentDate = self.myDatePicker.date;
    NSLog(@"Date = %@",currentDate);
    NSDate *oneYearFromToday = [currentDate dateByAddingTimeInterval:oneYearTime];
    NSDate *twoYearFromToday = [currentDate dateByAddingTimeInterval:2*oneYearTime];
    //最小可選時間
    self.myDatePicker.minimumDate = oneYearFromToday;
    self.myDatePicker.maximumDate = twoYearFromToday;
    [self.view addSubview:self.myDatePicker];
}

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

時間選擇：
.m文件：
[plain]
 (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    // Do any additional setup after loading the view from its nib. 
    self.view.backgroundColor = [UIColor whiteColor]; 
    //事件選擇器 
    self.myDatePicker = [[UIDatePicker alloc] init]; 
    self.myDatePicker.center = self.view.center; 
    //設置成時間模式 
    self.myDatePicker.datePickerMode=UIDatePickerModeCountDownTimer; 
    [self.view addSubview:self.myDatePicker]; 
    NSTimeInterval twoMinutes = 2*60; 
    [self.myDatePicker setCountDownDuration:twoMinutes]; 
} 

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    self.view.backgroundColor = [UIColor whiteColor];
    //事件選擇器
    self.myDatePicker = [[UIDatePicker alloc] init];
    self.myDatePicker.center = self.view.center;
    //設置成時間模式
    self.myDatePicker.datePickerMode=UIDatePickerModeCountDownTimer;
    [self.view addSubview:self.myDatePicker];
    NSTimeInterval twoMinutes = 2*60;
    [self.myDatePicker setCountDownDuration:twoMinutes];
}UIDatePickerMode類型：
[plain]
-type enmu{ 
    UIDatePickerModeTime,//時間 
    UIDatePickerModeDate,//日期 
    UIDatePickerModeDateAndTime,//時間和日期 
    UIDatePickerModeCountDownTimer//倒計時模式 
} 

-type enmu{
    UIDatePickerModeTime,//時間
    UIDatePickerModeDate,//日期
    UIDatePickerModeDateAndTime,//時間和日期
    UIDatePickerModeCountDownTimer//倒計時模式
}運行結果：