《简单的自定义DropDatePicker》-- UIPopoverController 和 代理 以及 Block 实现。

最近做项目为了方便项目使用，自定义的空间 写的比较粗糙。欢迎大家批评指正。
以上为在项目中的实际应用

 //  DropDownDatePicker.h
 //  DropDownDatePickerDemo
 //
 //  Created by HRP on 15/3/25.
 //  Copyright (c) 2015年 HRP. All rights reserved.
 //

 #import <UIKit/UIKit.h>
 typedef NS_ENUM(NSInteger, DropDownDatePickerMode)
 {
   DropDownDatePickerModeDate,
   DropDownDatePickerModeTime
 };

 @interface DropDownDatePicker : UIView

 - (id)initWithFrame:(CGRect)frame dateMode:(DropDownDatePickerMode)mode;

 @property (nonatomic, copy) void(^dateChangeHandler)(NSDate *);

 @property (nonatomic, readonly) UILabel         *titleLabel;
 @property (nonatomic, readonly) UIBarButtonItem *confrimButton;

 @property (nonatomic,strong   ) UIColor         *dateTextColor; //Default is Blue
 @property (nonatomic,strong   ) UIFont          *dateTextFont;  //Default is 14.0

 @property (nonatomic,strong   ) NSDate          *currentDate;   //Default is [NSDate date]

 @property (nonatomic,retain   ) NSDate          *minimumDate;   //Default is nil
 @property (nonatomic,retain   ) NSDate          *maximumDate;   //Default is nil

 @property (nonatomic,assign   ) NSInteger       minuteInterval;

 @end

 ===== 以下为DropDownDatePicker.m======

 //
 //  DropDownDatePicker.m
 //  DropDownDatePickerDemo
 //
 //  Created by  HRP on 15/3/25.
 //  Copyright (c) 2015年 HRP. All rights reserved.
 //

 #import "DropDownDatePicker.h"

 @protocol HRPDropDownDatePickerControllerDelegate <NSObject>

 @required

 - (void)datePickerControllerNeedDismiss;
 - (void)datePickerControllerDateChanged:(NSDate *)newDate;

 @end

 @interface HRPDropDownDatePickerController : UIViewController

 - (id)initWithDatePickerMode:(DropDownDatePickerMode)mode;

 @property (nonatomic) UIPopoverController *popover;

 @property (nonatomic,readonly ) UILabel         *titleLable;
 @property (nonatomic,readonly ) UIBarButtonItem *confrimButton;
 @property (nonatomic,readwrite) NSDate          *currentDate;

 @property (nonatomic,weak)id<HRPDropDownDatePickerControllerDelegate> delegate;

 @property (nonatomic,retain) NSDate *minimumDate;
 @property (nonatomic,retain) NSDate *maxmumDate;
 @property (nonatomic)        NSInteger minuteInterval;

 @end

 @implementation HRPDropDownDatePickerController
 {
   DropDownDatePickerMode  _mode;
   UIDatePicker           *_picker;
   NSDate                 *_lastDate;
 }

 - (id)initWithDatePickerMode:(DropDownDatePickerMode)mode
 {
   if (self = [super init])
   {
     _mode = mode;
   }
   return self;
 }

 - (void)viewDidLoad
 {
   _confrimButton = [[UIBarButtonItem alloc] initWithTitle:@"OK"
                                                     style:UIBarButtonItemStyleDone
                                                    target:self action:@selector(dismiss)];

   self.navigationItem.rightBarButtonItem = _confrimButton;

   _titleLable = [[UILabel alloc] initWithFrame:CGRectMake(, , , )];
   _titleLable.textColor         = [UIColor blueColor];
   _titleLable.font              = [UIFont systemFontOfSize:];
   self.navigationItem.titleView = _titleLable;

   _picker = [[UIDatePicker alloc] initWithFrame:CGRectMake(, , ,  - )];
   _picker.datePickerMode = (_mode == DropDownDatePickerModeDate)?UIDatePickerModeDate:UIDatePickerModeTime;
   [self.view addSubview:_picker];
 }

 - (void)dismiss
 {
   _lastDate = self.currentDate;

   if (![self.currentDate isEqual:_lastDate])
   {
     if (_delegate) {
       [_delegate datePickerControllerDateChanged:self.currentDate];
     }
   }
   if (_delegate) {
     [_delegate datePickerControllerNeedDismiss];
   }
 }

 - (void)setCurrentDate:(NSDate *)currentDate
 {
   [_picker setDate:currentDate animated:YES];
 }

 - (void)setMaxmumDate:(NSDate *)maxmumDate
 {
   _picker.maximumDate = maxmumDate;
 }

 - (void)setMinimumDate:(NSDate *)minimumDate
 {
   _picker.minimumDate = minimumDate;
 }

 - (NSDate *)currentDate
 {
   return _picker.date;
 }

 - (NSDate *)maxmumDate
 {
   return _picker.maximumDate;
 }

 - (NSDate *)minimumDate
 {
   return _picker.minimumDate;
 }

 - (void)setMinuteInterval:(NSInteger)minuteInterval
 {
   _picker.minuteInterval = minuteInterval;
 }

 @end

 @interface DropDownDatePicker()
 <HRPDropDownDatePickerControllerDelegate>

 @end

 @implementation DropDownDatePicker
 {
   UIButton                        *_button;
   UIPopoverController             *_popover;
   HRPDropDownDatePickerController *_controller;
   DropDownDatePickerMode           _mode;
   BOOL                             _needNotify;
 }

 - (id)initWithFrame:(CGRect)frame
            dateMode:(DropDownDatePickerMode)mode
 {
   self = [super initWithFrame:frame];
   if (self) {
     _needNotify = NO;
     _mode       = mode;
     UIImage *arrowImage = [UIImage imageNamed:@"HZDropDownDatePickerDownArrow"];
     CGRect  imageViewFrame = CGRectMake(CGRectGetWidth(self.bounds) - arrowImage.size.width - , , arrowImage.size.width, arrowImage.size.height);

     UIImageView *imageView = [[UIImageView alloc] initWithFrame:imageViewFrame];
     imageView.image           = arrowImage;
     imageView.backgroundColor = [UIColor redColor];
     [self addSubview:imageView];

     _button = [UIButton buttonWithType:UIButtonTypeSystem];
     _button.contentVerticalAlignment = UIControlContentHorizontalAlignmentLeft;
     _button.titleLabel.font          = [UIFont systemFontOfSize:14.0];
     _button.frame                    = self.bounds;
     [_button setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];

     [_button addTarget:self
                 action:@selector(showPopover)
       forControlEvents:UIControlEventTouchUpInside];

     [self addSubview:_button];

     _controller = [[HRPDropDownDatePickerController alloc] initWithDatePickerMode:mode];
     _controller.delegate = self;

     UINavigationController *navi = [[UINavigationController alloc] initWithRootViewController:_controller];
     if (!_popover) {
       _popover = [[UIPopoverController alloc] initWithContentViewController:navi];
       _popover.popoverContentSize = CGSizeMake(, );
     }
     else {
       [_popover setContentViewController:navi];
     }
     self.currentDate = [NSDate date];
   }
   return self;
 }

 - (UILabel *)titleLabel
 {
   return _controller.titleLable;
 }

 - (NSDate *)currentDate{
   return _controller.currentDate;
 }

 - (void)setDateTextFont:(UIFont *)dateTextFont
 {
   _button.titleLabel.font = dateTextFont;
 }

 - (UIFont *)dateTextFont
 {
   return _button.titleLabel.font;
 }

 - (void)setDateTextColor:(UIColor *)dateTextColor
 {
   [_button setTitleColor:dateTextColor forState:UIControlStateNormal];
 }

 - (UIColor *)dateTextColor
 {
   return [_button titleColorForState:UIControlStateNormal];
 }

 - (void)setCurrentDate:(NSDate *)currentDate
 {
   _controller.currentDate = currentDate;
   _needNotify = NO;
   [self datePickerControllerDateChanged:currentDate];
 }

 - (void)setMaximumDate:(NSDate *)maximumDate
 {
   _controller.maxmumDate = maximumDate;
 }

 - (NSDate *)maximumDate
 {
   return _controller.minimumDate;
 }

 - (void)setMinimumDate:(NSDate *)minimumDate
 {
   _controller.minimumDate = minimumDate;
 }

 - (NSDate *)minimumDate
 {
   return _controller.minimumDate;
 }

 - (NSInteger)minuteInterval{
   return _controller.minuteInterval;
 }

 - (void)setMinuteInterval:(NSInteger)minuteInterval{
   _controller.minuteInterval = minuteInterval;
 }

 -(UIBarButtonItem *)confrimButton{
   return _controller.confrimButton;
 }

 #pragma mark -
 #pragma mark delegate

 - (void)datePickerControllerNeedDismiss
 {
   [_popover dismissPopoverAnimated:YES];
 }

 - (void)datePickerControllerDateChanged:(NSDate *)newDate
 {
   NSString *dateString;
   NSDateFormatter* formater = [[NSDateFormatter alloc] init];
   if(_mode == DropDownDatePickerModeDate){
     formater.dateFormat = @"yyyy年 MM月 dd日";
   }
   else if(_mode == DropDownDatePickerModeTime){
     formater.dateFormat = @"hh: mm";
   }

   dateString = [formater stringFromDate:newDate];
   [_button setTitle:dateString forState:UIControlStateNormal];

   if(_dateChangeHandler && _needNotify){
     _dateChangeHandler(newDate);
   }
   _needNotify = YES;
 }

 #pragma mark Private Methods

 - (void)showPopover
 {
   CGFloat x = self.bounds.size.width / ;
   CGFloat y = self.bounds.size.height / ;

   [_popover presentPopoverFromRect:CGRectMake(x, y, , )
                             inView:_button
           permittedArrowDirections:UIPopoverArrowDirectionAny
                           animated:YES];
 }

 @end