#import "ViewController.h"
@interface ViewController ()<UIPickerViewDataSource,UIPickerViewDelegate>
展示数据的pickView
@property (weak, nonatomic) IBOutlet UIPickerView *pickView;
数组当中有3个小数组, 每一个小数组代表一列.每一列小数组的个数代表这一列有多少行.
@property(nonatomic,strong) NSArray *foodArray;
显示当前选中的食物
@property (weak, nonatomic) IBOutlet UILabel *foodLabel;
@end
@implementation ViewController
@end
@implementation ViewController
懒加载数据
-(NSArray *)foodArray{
if (_foodArray == nil) {
获取Plist文件的路径
NSString *filePath = [[NSBundle mainBundle] pathForResource:@"foods.plist" ofType:nil];
从Plist文件当中加载数组.
_foodArray = [NSArray arrayWithContentsOfFile:filePath];
}
return _foodArray;
}
}
return _foodArray;
}
- (void)viewDidLoad {
[super viewDidLoad];
设置数据源
self.pickView.dataSource = self;
设置代理
self.pickView.delegate = self;
}
}
总共有多少列
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
数组当中有几个元素, 就展示多少列.每一个元素代表一列,
return self.foodArray.count;
}
}
第component列有多少行.
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
取出当前所在的列.每一列都是一个数组.
NSArray *array = self.foodArray[component];
返回每一组当中, 每一个小数组的数个, 也就是这一组里面有多少行.
return array.count;
}
}
返回每一行的标题
- (nullable NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{
取出当前所在的列.每一列都是一个数组.
NSArray *componentArray = self.foodArray[component];
返回小数组当中每一个元素
return componentArray[row];
}
点击了哪一列的哪一行
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
NSString *food = self.foodArray[component][row];
NSString *food = self.foodArray[component][row];
self.foodLabel.text = food;
}