iPhone开发UI组件UIDatePickerView的预习

 新建工程如下：

编辑控制器的.h文件如下所示：

////  ViewController.h//  UIDatePickerVIew////  Created by apple on 15/9/2.//  Copyright (c) 2015年 LiuXun. All rights reserved.//#import <UIKit/UIKit.h>@interface ViewController : UIViewController <UIPickerViewDataSource,UIPickerViewDelegate>{    int a;    int b;    int t;}@property (nonatomic, strong) UIPickerView *pickView;@property (nonatomic, strong) NSMutableArray *pickerNameArray;@property (nonatomic, strong) NSMutableArray *pickerPlaceArray;@property (nonatomic, strong) NSMutableDictionary *typeDictionary;@property (nonatomic, strong) UILabel * lblSelect;@property (nonatomic, strong) NSString *selectStr;@property (nonatomic, strong) NSTimer * timer;@property (nonatomic, strong) UIButton *btn;@property (nonatomic, strong) UIImageView *zhen;@property (nonatomic, strong) UIImageView *pan;@end

编辑控制器的.m文件如下所示：

////  ViewController.m//  UIDatePickerVIew////  Created by apple on 15/9/2.//  Copyright (c) 2015年 LiuXun. All rights reserved.//#import "ViewController.h"#define WIDTH    [UIScreen mainScreen].bounds.size.width#define HEIGHT  [UIScreen mainScreen].bounds.size.height@interface ViewController ()@property (nonatomic, strong) NSString *str1;@property (nonatomic, strong) NSString *str2;@property (nonatomic, strong) NSDate *start;@property (nonatomic, strong) NSDate *end;@end@implementation ViewController- (void)viewDidLoad{    [super viewDidLoad];[self assignForPickView];        self.pickView = [[UIPickerView alloc] initWithFrame:CGRectMake(10, WIDTH/2+50, WIDTH-20, WIDTH/3)];    self.pickView.backgroundColor = [UIColor yellowColor];    self.pickView.dataSource = self;    self.pickView.delegate = self;    self.pickView.showsSelectionIndicator = YES;    [self.view addSubview:self.pickView];         // 显示数据    self.lblSelect = [[UILabel alloc ] initWithFrame:CGRectMake(0, 10, WIDTH, WIDTH/6)];    self.lblSelect .text = self.selectStr;    self.lblSelect.textAlignment = NSTextAlignmentCenter;    [self.view addSubview:self.lblSelect];        // button    self.btn = [[UIButton alloc] initWithFrame:CGRectMake(10, WIDTH/2+WIDTH/3+100, WIDTH-20, WIDTH/5)];    [self.btn  setTitle:@"点击抽奖" forState:UIControlStateNormal];    [self.btn setTitle:@"开始抽奖" forState:UIControlStateHighlighted];    [self.btn addTarget:self action:@selector(chouJiang) forControlEvents:UIControlEventTouchUpInside];    [self.btn setBackgroundColor:[UIColor redColor]];    [self.view addSubview:self.btn];        // 显示表盘    self.pan = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, (WIDTH-40)/2, (WIDTH-40)/2)];    self.pan.center = CGPointMake(WIDTH/2, 120);    self.pan.image = [UIImage imageNamed:@"1.png"];    [self.view addSubview:self.pan];        // 显示表针    self.zhen = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 11, (WIDTH - 40)/4)];    self.zhen.center = CGPointMake(WIDTH/2, 120);    self.zhen.image = [UIImage imageNamed:@"3.png"];    [self.view addSubview:self.zhen];    [self.view bringSubviewToFront:self.lblSelect];    } //抽奖监听方法-(void)chouJiang{     self.start  = [[NSDate alloc] init];       NSLog(@"t1= %d",t);    self.timer = [NSTimer scheduledTimerWithTimeInterval:0.01 target:self selector:@selector(jiang) userInfo:nil repeats:YES];   }-(void) jiang{    self.end = [[NSDate alloc] init];    t = self.start.timeIntervalSince1970;    int t2 = self.end.timeIntervalSince1970;    NSLog(@"t2= %d  t1= %d",t2,t);    if ((t2 - t) == 5 ) {        [self.timer invalidate];    }    int b1 = arc4random()%100+100000;      for (int i = 0; i<b1 ; i++) {        self.zhen.transform = CGAffineTransformRotate(self.zhen.transform, -M_PI_4/180);    }        a = arc4random() % (self.pickerNameArray.count);    NSMutableArray  *BB = [self.typeDictionary  objectForKey:self.pickerNameArray[a]];        b = arc4random() % (BB.count);        [self  pickerView:self.pickView didSelectRow:a inComponent:0];    [self  pickerView:self.pickView didSelectRow:b inComponent:1];    [self.pickView reloadComponent:0];    [self.pickView  selectRow:a inComponent:0 animated:YES];        }-(void) assignForPickView{    self.pickerNameArray =[ [NSMutableArray alloc] initWithObjects:@"河南",@"北京",@"山东",@"河北" ,nil];    NSMutableArray *hArr = [NSMutableArray arrayWithObjects:@"周口", @"郑州",@"焦作",@"驻马店",nil];    NSMutableArray *bArr = [NSMutableArray arrayWithObjects:@"昌平",@"海淀",@"朝阳",@"丰台",@"大兴", nil];    NSMutableArray *sArr = [NSMutableArray arrayWithObjects:@"青岛",@"烟台", nil];    NSMutableArray *hBArr = [NSMutableArray arrayWithObjects:@"石家庄", nil];    NSMutableArray *typeArr = [NSMutableArray arrayWithObjects:hArr,bArr,sArr,hBArr, nil];    self.typeDictionary = [NSMutableDictionary dictionaryWithObjects:typeArr forKeys:self.pickerNameArray];    self.pickerPlaceArray = hArr;    }// 分为多少列-(NSInteger) numberOfComponentsInPickerView:(UIPickerView *)pickerView{    return 2;  } // 每一列有多少行-(NSInteger) pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{    NSInteger row = 0;    switch (component) {        case 0:            row = self.pickerNameArray.count;            break;        case 1:            row = self.pickerPlaceArray.count;            break;    }    return row;} //  利用系统自带的格式。-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{    if (component == 0) {        return self.pickerNameArray[row];    }    else    {        return self.pickerPlaceArray[row];    }  }// 自定义格式-(UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view{    UILabel *contentLabel = nil;    if (component == 0) {        contentLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 100, 30)];        contentLabel.textAlignment = NSTextAlignmentCenter;        contentLabel.text = self.pickerNameArray[row];        contentLabel.font = [UIFont systemFontOfSize:14];        contentLabel.backgroundColor = [UIColor cyanColor];    }else    {        contentLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 180, 30)];        contentLabel.text = self.pickerPlaceArray[row];        contentLabel.textAlignment = NSTextAlignmentCenter;        contentLabel.font = [UIFont systemFontOfSize:14];        contentLabel.backgroundColor = [UIColor darkGrayColor];    }    return contentLabel;}-(void) pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{    switch (component) {        case 0:        {            self.str1 = self.pickerNameArray[row];            self.pickerPlaceArray = self.typeDictionary[self.str1];            if (self.pickerPlaceArray.count >1) {                self.selectStr = [NSString stringWithFormat:@"%@, %@",self.str1,[self.pickerPlaceArray objectAtIndex:b]];            }            else            {                self.selectStr = self.str1;                        }                        // 更新视图            [pickerView reloadComponent:1];            [pickerView selectRow:b inComponent:1 animated:YES];        }            break;        case 1 :        {            self.str2 = self.pickerPlaceArray[row];            self.selectStr = [NSString stringWithFormat:@"%@ ,%@",self.str1,self.str2];            break;        }        break;    }    self.lblSelect.text = self.selectStr;}  // 设置每一列的行高-(CGFloat) pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component{    return 40;}// 设置每一列的宽度-(CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component{    CGFloat width = 0.0;    if (component == 0) {        width = 100;    }    else        width = 180;    return width;}- (void)didReceiveMemoryWarning{        [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end

运行结果如下：