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：