1 //  Created by 鑫 on 14-10-15.  2   3 //  Copyright (c) 2014年 梁镋鑫. All rights reserved.  4   5 //  6   7    8   9 #import "TXViewController.h" 10  11   12  13 @interface TXViewController ()<UIPickerViewDataSource,UIPickerViewDelegate> 14  15 @property (weak, nonatomic) IBOutlet UIPickerView *pickerView; 16  17 - (IBAction)randomFood; 18  19 @property(nonatomic ,strong)NSArray *foods; 20  21 @property (weak, nonatomic) IBOutlet UILabel *fruitLabel; 22  23 @property (weak, nonatomic) IBOutlet UILabel *mainLabel; 24  25 @property (weak, nonatomic) IBOutlet UILabel *drinkLabel; 26  27   28  29 @end 30  31   32  33 @implementation TXViewController 34  35   36  37 - (void)viewDidLoad 38  39 { 40  41     [super viewDidLoad]; 42  43 // Do any additional setup after loading the view,typically from a nib. 44  45      46  47     //初始化 48  49 //    self.fruitLabel.text =self.foods[0][0]; 50  51 //    self.mainLabel.text =self.foods[1][0]; 52  53 //    self.drinkLabel.text =self.foods[2][0]; 54  55     //手动调用代理方法  所以可用for循环，上面不可以 56  57 //    [self pickerView:nil didSelectRow:0inComponent:0]; 58  59 //    [self pickerView:nil didSelectRow:0inComponent:1]; 60  61 //    [self pickerView:nil didSelectRow:0inComponent:2]; 62  63     for ( intComponent  = 0; Component < self.foods.count; Component++) { 64  65         [self pickerView:nil didSelectRow:0 inComponent:Component]; 66  67     } 68  69      70  71 } 72  73   74  75   76  77 //随机选中某一食物 78  79   80  81 - (IBAction)randomFood { 82  83      84  85     //生成随机数 86  87      88  89     //arc4random()%14; 生成0到14的随机数 ,[self.foods[0] count]取出第0列这个数组，这个数组在调用count这个方法 90  91 //    [self.pickerViewselectRow:arc4random()%[self.foods[0] count] inComponent:0 animated:YES]; 92  93 //    [self.pickerViewselectRow:arc4random()%[self.foods[1] count] inComponent:1 animated:YES]; 94  95 //    [self.pickerViewselectRow:arc4random()%[self.foods[2] count] inComponent:2animated:YES]; 96  97      98  99     //  用for循环100 101     for (intcomponent = 0; component < self.foods.count; component++) {102 103         //第component列数组的总长度104 105         intcount = [self.foods[component]count];106 107         //之前的行号108 109         intoldrow = [self.pickerView selectedRowInComponent:component];110 111         //第几行 默认新的行号跟旧的行号一样112 113         introw =oldrow;114 115     116 117     //    arc4random()%count等价arc4random_uniform(count);118 119         //保证行数不一样120 121         //之前的行号122 123        124 125         while (row ==oldrow) {126 127             row = arc4random()%count;128 129         }130 131         //让pickerView主动选中第component列第row行132 133         [self.pickerView selectRow:row inComponent:componentanimated:YES];134 135         136 137         //设置label的文字138 139         [self pickerView:nil didSelectRow:row inComponent:component];140 141  142 143     }144 145     146 147     148 149     150 151     152 153     154 155 }156 157  158 159 -(NSArray *)foods160 161 {162 163     if (_foods == nil) {164 165         _foods = [NSArray arrayWithContentsOfFile:[[NSBundlemainBundle]pathForResource:@"foods" ofType:@"plist"]];166 167     }168 169     return _foods;170 171 }172 173  174 175  176 177  178 179 #pragma mark ---数据源方法180 181 //一共多少列182 183 -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView184 185 {186 187     return self.foods.count;188 189 }190 191 //列。(NSInteger)component  第(NSInteger)componentl列显示多少行192 193 -(NSInteger)pickerView:(UIPickerView *)pickerViewnumberOfRowsInComponent:(NSInteger)component194 195 {196 197    // 先取出第component列的数组198 199     NSArray *subfoods = self.foods[component];200 201     return subfoods.count;202 203 }204 205  206 207  208 209 #pragma mark  - - 代理方法210 211 -(NSString *)pickerView:(UIPickerView *)pickerViewtitleForRow:(NSInteger)row forComponent:(NSInteger)component212 213 {214 215     //先取出第component列，在取出这个数组这一行216 217     return self.foods[component][row];218 219 }220 221 //选中第component列第row行222 223 -(void)pickerView:(UIPickerView *)pickerViewdidSelectRow:(NSInteger)row inComponent:(NSInteger)component224 225 {226 227     228 229     NSLog(@"选中了第%d列第%d行",component, row);230 231     if (component ==0){232 233         self.fruitLabel.text = self.foods[component][row];234 235         236 237     }238 239     else if(component==1)240 241     {242 243         self.mainLabel.text = self.foods[component][row];244 245     }246 247     else if(component  == 2)248 249     {250 251         self.drinkLabel.text = self.foods[component][row];252 253     }254 255     256 257     258 259     260 261     262 263     264 265     266 267 }268 269  270 271  272 273 @end

1.UIPickerView的常见属性// 数据源(用来告诉UIPickerView有多少列多少行)@property(nonatomic,assign) id<UIPickerViewDataSource> dataSource;// 代理(用来告诉UIPickerView每1列的每1行显示什么内容,监听UIPickerView的选择)@property(nonatomic,assign) id<UIPickerViewDelegate>   delegate;// 是否要显示选中的指示器@property(nonatomic)        BOOL                      showsSelectionIndicator;// 一共有多少列@property(nonatomic,readonly) NSInteger numberOfComponents; 2.UIPickerView的常见方法// 重新刷新所有列- (void)reloadAllComponents;// 重新刷新第component列- (void)reloadComponent:(NSInteger)component; // 主动选中第component列的第row行- (void)selectRow:(NSInteger)rowinComponent:(NSInteger)component animated:(BOOL)animated; // 获得第component列的当前选中的行号-(NSInteger)selectedRowInComponent:(NSInteger)component; 3.数据源方法(UIPickerViewDataSource)//  一共有多少列-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView;//  第component列一共有多少行- (NSInteger)pickerView:(UIPickerView *)pickerViewnumberOfRowsInComponent:(NSInteger)component; 4.代理方法(UIPickerViewDelegate)//  第component列的宽度是多少- (CGFloat)pickerView:(UIPickerView *)pickerViewwidthForComponent:(NSInteger)component;//  第component列的行高是多少- (CGFloat)pickerView:(UIPickerView *)pickerViewrowHeightForComponent:(NSInteger)component; //  第component列第row行显示什么文字- (NSString *)pickerView:(UIPickerView *)pickerViewtitleForRow:(NSInteger)row forComponent:(NSInteger)component; //  第component列第row行显示怎样的view(内容)- (UIView *)pickerView:(UIPickerView *)pickerViewviewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView*)view; //  选中了pickerView的第component列第row行- (void)pickerView:(UIPickerView *)pickerViewdidSelectRow:(NSInteger)row inComponent:(NSInteger)component;