iOS开发UI篇—UIPickerView控件简单介绍
一.UIPickerView 控件
1.简单介绍：
2.示例代码
TXViewController.m文件
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 *)foods 160 161 { 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 *)pickerView 184 185 { 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)component 194 195 { 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)component 212 213 { 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)component 224 225 { 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
实现效果：
二.UIPickerView 用法
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;