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 //
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7
8
9 #import "TXViewController.h"
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11
12
13 @interface TXViewController ()<UIPickerViewDataSource,UIPickerViewDelegate>
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15 @property (weak, nonatomic) IBOutlet UIPickerView *pickerView;
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17 - (IBAction)randomFood;
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19 @property(nonatomic ,strong)NSArray *foods;
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21 @property (weak, nonatomic) IBOutlet UILabel *fruitLabel;
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23 @property (weak, nonatomic) IBOutlet UILabel *mainLabel;
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25 @property (weak, nonatomic) IBOutlet UILabel *drinkLabel;
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27
28
29 @end
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31
32
33 @implementation TXViewController
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35
36
37 - (void)viewDidLoad
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39 {
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41 [super viewDidLoad];
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43 // Do any additional setup after loading the view,typically from a nib.
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45
46
47 //初始化
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49 // self.fruitLabel.text =self.foods[0][0];
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51 // self.mainLabel.text =self.foods[1][0];
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53 // self.drinkLabel.text =self.foods[2][0];
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55 //手动调用代理方法 所以可用for循环，上面不可以
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57 // [self pickerView:nil didSelectRow:0inComponent:0];
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59 // [self pickerView:nil didSelectRow:0inComponent:1];
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61 // [self pickerView:nil didSelectRow:0inComponent:2];
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63 for ( intComponent = 0; Component < self.foods.count; Component++) {
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65 [self pickerView:nil didSelectRow:0 inComponent:Component];
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67 }
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69
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71 }
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75
76
77 //随机选中某一食物
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81 - (IBAction)randomFood {
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83
84
85 //生成随机数
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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
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91 // [self.pickerViewselectRow:arc4random()%[self.foods[0] count] inComponent:0 animated:YES];
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93 // [self.pickerViewselectRow:arc4random()%[self.foods[1] count] inComponent:1 animated:YES];
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95 // [self.pickerViewselectRow:arc4random()%[self.foods[2] count] inComponent:2animated:YES];
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97
98
99 // 用for循环
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101 for (intcomponent = 0; component < self.foods.count; component++) {
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103 //第component列数组的总长度
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105 intcount = [self.foods[component]count];
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107 //之前的行号
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109 intoldrow = [self.pickerView selectedRowInComponent:component];
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111 //第几行 默认新的行号跟旧的行号一样
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113 introw =oldrow;
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115
116
117 // arc4random()%count等价arc4random_uniform(count);
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119 //保证行数不一样
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121 //之前的行号
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123
124
125 while (row ==oldrow) {
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127 row = arc4random()%count;
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129 }
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131 //让pickerView主动选中第component列第row行
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133 [self.pickerView selectRow:row inComponent:componentanimated:YES];
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135
136
137 //设置label的文字
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139 [self pickerView:nil didSelectRow:row inComponent:component];
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141
142
143 }
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155 }
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159 -(NSArray *)foods
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161 {
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163 if (_foods == nil) {
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165 _foods = [NSArray arrayWithContentsOfFile:[[NSBundlemainBundle]pathForResource:@"foods" ofType:@"plist"]];
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167 }
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169 return _foods;
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171 }
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178
179 #pragma mark ---数据源方法
180
181 //一共多少列
182
183 -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
184
185 {
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187 return self.foods.count;
188
189 }
190
191 //列。(NSInteger)component 第(NSInteger)componentl列显示多少行
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193 -(NSInteger)pickerView:(UIPickerView *)pickerViewnumberOfRowsInComponent:(NSInteger)component
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195 {
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197 // 先取出第component列的数组
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199 NSArray *subfoods = self.foods[component];
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201 return subfoods.count;
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203 }
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207
208
209 #pragma mark - - 代理方法
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211 -(NSString *)pickerView:(UIPickerView *)pickerViewtitleForRow:(NSInteger)row forComponent:(NSInteger)component
212
213 {
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215 //先取出第component列，在取出这个数组这一行
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217 return self.foods[component][row];
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219 }
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221 //选中第component列第row行
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223 -(void)pickerView:(UIPickerView *)pickerViewdidSelectRow:(NSInteger)row inComponent:(NSInteger)component
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225 {
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227
228
229 NSLog(@"选中了第%d列第%d行",component, row);
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231 if (component ==0){
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233 self.fruitLabel.text = self.foods[component][row];
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235
236
237 }
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239 else if(component==1)
240
241 {
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243 self.mainLabel.text = self.foods[component][row];
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245 }
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247 else if(component == 2)
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249 {
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251 self.drinkLabel.text = self.foods[component][row];
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253 }
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267 }
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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;
时间： 2024-10-24 09:52:41