iOS中UIPickerView实现省/市连动

UIPickerView实现省/市的连动

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<UIPickerViewDelegate,UIPickerViewDataSource>
@property(strong,nonatomic) UIPickerView *myPickView;
@property(strong,nonatomic) NSArray *array;//用于存储数据
@property(strong,nonatomic) NSMutableArray *provinceArray;//省份数组
@property(strong,nonatomic) NSMutableArray *cityArray;//城市数组
@property(strong,nonatomic) UIAlertController *alterController;
@property(strong,nonatomic) UIAlertAction *actionA;
@property(strong,nonatomic) UIAlertAction *actionB;

@end

#import "ViewController.h"

@interface ViewController ()


@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    //初始化
    self.provinceArray=[NSMutableArray array];
    self.cityArray=[NSMutableArray array];
    
    self.myPickView=[[UIPickerView alloc] initWithFrame:CGRectMake(30, 100, 350, 200)];
    self.myPickView.backgroundColor=[UIColor greenColor];
    //指定代理
    self.myPickView.delegate=self;
    self.myPickView.dataSource=self;
    
    [self.view addSubview:self.myPickView];
    
    //提取文件
    NSString *path=[[NSBundle mainBundle] pathForResource:@"city" ofType:@"plist"];
    self.array=[NSArray arrayWithContentsOfFile:path];
    
    //把地区数据提取出来存储到 dic 字典中
    for (NSDictionary *dic in self.array) {
        //把字典 dic 中的省提取出来放到集合 provinceArray 中
        [self.provinceArray addObject:dic[@"State"]];
    }
    //NSLog(@"%@",self.provinceArray);
    
    
    
    
}

-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return 2; //输出的是两列
}

-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    if (component==0) {
        return self.provinceArray.count;
    }else
    {
        return self.cityArray.count;
    }
}

-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    if (component==0) {
        return [self.provinceArray objectAtIndex:row];
    }
    return [self.cityArray objectAtIndex:row];
}

-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
    if (component==0)
    {
        //清除上次选择的城市
        [self.cityArray removeAllObjects];
        NSDictionary *dic=[self.array objectAtIndex:row];
        NSArray *array1=dic[@"Cities"];
        NSMutableArray *cityA=[NSMutableArray array];
        for (NSDictionary *tempdic in array1) {
            [cityA addObject:tempdic[@"city"]];
        }
        self.cityArray=cityA;
        [self.myPickView selectRow:row inComponent:0 animated:YES];
        //刷新组件
        [self.myPickView reloadComponent:1];
    }
    if(component==1){
        
        NSInteger integerFirst=[self.myPickView selectedRowInComponent:0];
        NSInteger integerTow=[self.myPickView selectedRowInComponent:1];
        NSString *firstStr=[self.provinceArray objectAtIndex:integerFirst];
        NSString *towStr=[self.cityArray objectAtIndex:integerTow];
        NSString *str=[NSString stringWithFormat:@"您要选择的是:%@, %@吗？",firstStr,towStr];
        self.alterController=[UIAlertController alertControllerWithTitle:@"系统提示" message:str preferredStyle:UIAlertControllerStyleAlert];
        self.actionA=[UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:nil];
        self.actionB=[UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:nil];
        [self.alterController addAction:self.actionA];
        [self.alterController addAction:self.actionB];
        [self presentViewController:self.alterController animated:YES completion:nil];
    }

}

-(CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component
{
    return 40;
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}