iOS开发UI篇—使用picker View控件完成一个简单的选餐应用

  1//  2//  YYViewController.m
  3//  06-简单选菜系统的实现
  4//  5//  Created by apple on 14-6-5.
  6//  Copyright (c) 2014年 itcase. All rights reserved.
  7//
  8  9#import"YYViewController.h" 10 11//遵守数据源和代理协议 12@interface YYViewController ()<UIPickerViewDataSource,UIPickerViewDelegate>
 13/**
 14 *  水果
 15*/ 16 @property (strong, nonatomic) IBOutlet UILabel *fruitLab;
 17/**
 18 *  主菜
 19*/ 20 @property (strong, nonatomic) IBOutlet UILabel *stapleLab;
 21/**
 22 *  饮料
 23*/ 24 @property (strong, nonatomic) IBOutlet UILabel *drinkLab;
 25/**
 26 *  保存所有的数据
 27*/ 28 @property(nonatomic,strong)NSArray *foods;
 29 @property (weak, nonatomic) IBOutlet UIPickerView *pickerView;
 30 - (IBAction)randomFood:(id)sender;
 31 32@end 33 34@implementation YYViewController
 35 36 - (void)viewDidLoad
 37{
 38    [super viewDidLoad];
 39 40//在这里设置下方数据刷新部分的初始显示 41for (int component = 0; component<self.foods.count; component++) {
 42         [self pickerView:nil didSelectRow:0 inComponent:component];
 43    }
 44}
 45 46#pragma mark-使用懒加载，把数据信息加载进来
 47 -(NSArray *)foods
 48{
 49if (_foods==nil) {
 50         NSString *fullpath = [[NSBundle mainBundle] pathForResource:@"foods.plist" ofType:nil];
 51         NSArray *arrayM = [NSArray arrayWithContentsOfFile:fullpath];
 52         _foods = arrayM;
 53    }
 54return _foods;
 55}
 56 57#pragma mark-处理随机按钮的点击事件
 58 - (IBAction)randomFood:(id)sender {
 59 60// 让pickerView主动选中某一行
 61// 让pickerView选中inComponent列的Row行
 62//    [self.pickerView selectRow:1 inComponent:0 animated:YES]; 63 64/* 65     [self.pickerView selectRow: arc4random() % 12 inComponent:0 animated:YES];
 66     [self.pickerView selectRow: arc4random() % 15 inComponent:1 animated:YES];
 67     [self.pickerView selectRow: arc4random() % 10 inComponent:2 animated:YES];
 68*/ 69 70//    [self.foods objectAtIndex:0]; == self.foods[0];
 71//    [self.foods[0] count]; 72 73/* 74     // 根据每一列的元素个数生成随机值
 75     [self.pickerView selectRow: arc4random() % [self.foods[0] count] inComponent:0 animated:YES];
 76     [self.pickerView selectRow: arc4random() % [self.foods[1] count] inComponent:1 animated:YES];
 77     [self.pickerView selectRow: arc4random() % [self.foods[2] count] inComponent:2 animated:YES];
 78*/ 79 80// 设置一个随机数 81for (int component = 0; component < self.foods.count; component++) {
 82// 获取当前列对应的数据元素的个数 83int total = [self.foods[component] count];
 84// 根据每一列的总数生成随机数（当前生成的随机数） 85int randomNumber = arc4random() % total;
 86 87// 获取当前选中的行（上一次随机后移动到的行） 88int oldRow = [self.pickerView selectedRowInComponent:component];
 89 90// 比较上一次的行号和当前生成的随机数是否相同，如果相同的话则重新生成 91while (oldRow == randomNumber) {
 92                 randomNumber = arc4random() % total;
 93        }
 94 95// 让pickerview滚动到指定的某一行 96        [self.pickerView selectRow:randomNumber inComponent:component animated:YES];
 97// 模拟，通过代码选中某一行 98        [self pickerView:nil didSelectRow:randomNumber inComponent:component];
 99    }
100}
101102#pragma mark - 设置数据
103// 一共多少列104 -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
105{
106return self.foods.count;
107}
108109// 每列对应多少行110 -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
111{
112// 1.获取当前的列113     NSArray *arayM = self.foods[component];
114//2.返回当前列对应的行数115return arayM.count;
116}
117118// 每列每行对应显示的数据是什么119 -(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
120{
121// 1.获取当前的列122     NSArray *arayM = self.foods[component];
123// 2.获取当前列对应的行的数据124     NSString *name = arayM[row];
125return name;
126}
127128#pragma mark-设置下方的数据刷新
129// 当选中了pickerView的某一行的时候调用
130// 会将选中的列号和行号作为参数传入
131// 只有通过手指选中某一行的时候才会调用132 -(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
133{
134// 获取对应列，对应行的数据135     NSString *name = self.foods[component][row];
136// 赋值137if (0 == component) {
138         self.fruitLab.text = name;
139     }elseif(1 == component)
140    {
141         self.stapleLab.text = name;
142     }else143         self.drinkLab.text = name;
144}
145146#pragma mark-隐藏状态栏
147 -(BOOL)prefersStatusBarHidden
148{
149return YES;
150}
151@end