#import "ViewController.h"@interface ViewController ()<UIPickerViewDataSource, UIPickerViewDelegate>- (IBAction)selectAnyFood;@property (weak, nonatomic) IBOutlet UIPickerView *pickView;@property (weak, nonatomic) IBOutlet UILabel *fruitLab;@property (weak, nonatomic) IBOutlet UILabel *foodLab;@property (weak, nonatomic) IBOutlet UILabel *drinkLab;@property (nonatomic, strong) NSArray *foods;@end@implementation ViewController#pragma mark - 懒加载数据- (NSArray *)foods{    if (!_foods) {                NSString *path = [[NSBundle mainBundle] pathForResource:@"foods.plist" ofType:nil];        NSArray *foodsArr = [NSArray arrayWithContentsOfFile:path];        _foods = foodsArr;    }    return _foods;}- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.        // 视图加载完毕默认显示第0行数据    for (int i = 0; i<self.foods.count; i++) {                [self pickerView:nil didSelectRow:0 inComponent:i];    }    }#pragma mark - 数据源方法- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{    return self.foods.count;}- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{    // 注意为什么 self.foods[component]不能用点语法点出count？    /**     *  [self.foods objectAtIndex:0]; == self.foods[0];//这两句的效果等价，而self调用objectAtIndex:0这个方法，返回的是一个id类型的万能指针，它的真实类型要到实际运行的时候才能检测得到，因此不能直接使用self.foods[0].count。     */    return [self.foods[component] count];}#pragma mark - 代理方法- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{    return self.foods[component][row];}- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{    if (component == 0) {                self.fruitLab.text = self.foods[component][row];    } else if(component == 1) {        self.foodLab.text = self.foods[component][row];    } else {        self.drinkLab.text = self.foods[component][row];    }}/** *  随机点餐 */- (IBAction)selectAnyFood {        for (int i = 0; i<self.foods.count; i++) {                // 取出被选中的行        int row =(int)[self.pickView selectedRowInComponent:i];        int random;        do {            random = arc4random() % [self.foods[i] count];        } while (row == random);                [self.pickView selectRow:random inComponent:i animated:YES];        [self pickerView:nil didSelectRow:random inComponent:i];    }}@end

#import <Foundation/Foundation.h>@interface LLFlag : NSObject@property (nonatomic, copy) NSString *name;@property (nonatomic, copy) NSString *icon;- (instancetype)initWithDic:(NSDictionary *)dic;+ (instancetype)flagWithDic:(NSDictionary *)dic;+ (NSArray *)flagsList;@end

#import "LLFlag.h"@implementation LLFlag- (instancetype)initWithDic:(NSDictionary *)dic{    if (self = [super init]) {        [self setValuesForKeysWithDictionary:dic];    }    return self;}+ (instancetype)flagWithDic:(NSDictionary *)dic{    return [[self alloc] initWithDic:dic];}+ (NSArray *)flagsList{    NSString *path = [[NSBundle mainBundle] pathForResource:@"flags" ofType:@"plist"];    NSArray *dicArr = [NSArray arrayWithContentsOfFile:path];        NSMutableArray *tmpArr = [[NSMutableArray alloc] initWithCapacity:dicArr.count];    for (NSDictionary *dic in dicArr) {                LLFlag *flag = [LLFlag flagWithDic:dic];                [tmpArr addObject:flag];    }    return tmpArr;}@end

#import <UIKit/UIKit.h>@class LLFlag;@interface LLFlagView : UIView@property (nonatomic, strong) LLFlag *flag;+ (instancetype)flagView;@end

#import "LLFlagView.h"#import "LLFlag.h"@interface LLFlagView ()@property (weak, nonatomic) IBOutlet UILabel *nameLabel;@property (weak, nonatomic) IBOutlet UIImageView *iconView;@end@implementation LLFlagView+ (instancetype)flagView{    LLFlagView *view = [[[NSBundle mainBundle] loadNibNamed:@"LLFlagView" owner:nil options:nil] lastObject];        return view;}- (void)setFlag:(LLFlag *)flag{    _flag = flag;        self.nameLabel.text = flag.name;    self.iconView.image = [UIImage imageNamed:flag.icon];}@end

#import "ViewController.h"#import "LLFlag.h"#import "LLFlagView.h"@interface ViewController ()<UIPickerViewDataSource, UIPickerViewDelegate>@property (nonatomic, strong) NSArray *flags;@property (weak, nonatomic) IBOutlet UIPickerView *pickView;@end@implementation ViewController#pragma mark - 懒加载- (NSArray *)flags{    if (!_flags) {                _flags = [LLFlag flagsList];    }    return _flags;}- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.}#pragma mark - 数据源方法- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{    return 1;}- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{    return self.flags.count;}- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view{    LLFlagView *flagView = [LLFlagView flagView];    flagView.flag = self.flags[row];    return flagView;}- (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component{    return 50;}@end