UIPickerView
#import "ViewController.h" @interface ViewController ()<UIPickerViewDataSource,UIPickerViewDelegate> @property (nonatomic,strong)NSArray *foods;
@property (weak, nonatomic) IBOutlet UILabel *fruitLabel;
@property (weak, nonatomic) IBOutlet UILabel *mainFoodLabel;
@property (weak, nonatomic) IBOutlet UILabel *drinkLabel; - (IBAction)randomMenu;
@property (weak, nonatomic) IBOutlet UIPickerView *pickerView; @end @implementation ViewController -(NSArray *)foods{
if (!_foods) {
NSString *filePath = [[NSBundle mainBundle] pathForResource:@"foods.plist" ofType:nil];
_foods = [NSArray arrayWithContentsOfFile:filePath];
} return _foods;
} - (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib. NSLog(@"%@",self.foods); //默认选中数据，第一行数据
// [self pickerView:nil didSelectRow:0 inComponent:0];
// [self pickerView:nil didSelectRow:0 inComponent:1];
// [self pickerView:nil didSelectRow:0 inComponent:2]; NSInteger columns = self.foods.count;
for (int i = ; i < columns; i++) {
[self pickerView:nil didSelectRow: inComponent:i];
} } #pragma mark UIPickerView数据源
#pragma mark 列数
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
return self.foods.count;
} #pragma mark 每一列的行数
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{ //获取每一列的数据
NSArray *items = self.foods[component]; //返回每一列的个数据
return items.count;
} #pragma mark UIPickerView代理
-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{ //获取每一列的数据
NSArray *items = self.foods[component]; //返回对应列的行的数据
return items[row];
} #pragma mark pickerView的选中
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
NSLog(@"component %ld row %ld",component,row); //获取数据
NSArray *items = self.foods[component];
NSString *rowStr = items[row]; //更改数据
switch (component) {
case ://水果
self.fruitLabel.text = rowStr;
break;
case ://主食
self.mainFoodLabel.text = rowStr;
break;
case ://饮料
self.drinkLabel.text = rowStr;
break; default:
break;
} } #pragma mark 随机菜单，由天决定我们吃什么
- (IBAction)randomMenu {
NSLog(@"xx");
// 1.获取每列有多少行
NSInteger columns = self.foods.count; for (int i = ; i < columns; i ++) { NSArray *items = self.foods[i];
//对应列的行数 NSInteger rowsInColumn = items.count; // 2.在行范围产生随机数据
NSInteger randomRow =arc4random_uniform((int)rowsInColumn); //每列的随机行数不能与之前一样
// 获取旧的行数
NSInteger oldRow = [self.pickerView selectedRowInComponent:i]; while (oldRow == randomRow ) {
randomRow =arc4random_uniform((int)rowsInColumn);
} // 0.0~0.9
//arc4random_uniform(10) * 0.1 // 0.00~0.99
//arc4random_uniform(100) * 0.01 // 3.更改数据
// 3.1 更改label的数据
[self pickerView:nil didSelectRow:randomRow inComponent:i]; #warning 要改变PIckerview选中的行，要使用pickerview的一个方法
// 3.1 更改UIPickerView选中的数据
[self.pickerView selectRow:randomRow inComponent:i animated:YES];
} }
@end