#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<UIPickerViewDataSource,UIPickerViewDelegate>

@property(strong,nonatomic)UIPickerView *pickView;

//定义一个可变数组用于存放省的数据

@property(strong,nonatomic)NSMutableArray *Statearry;

//定义一个可变数组用于存放市的数据

@property(strong,nonatomic)NSMutableArray *Citiesarry;

//定义一个集合分别存省和市的数据

@property(strong,nonatomic)NSArray *arry;

@end

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

//获取数据

NSString *path=[[NSBundle mainBundle] pathForResource:@"city" ofType:@"plist"];

//初始化省和市的数组

self.Statearry=[NSMutableArray array];

self.Citiesarry=[NSMutableArray array];

//ayyr这个大数组存放所有的省市

self.arry=[NSArray arrayWithContentsOfFile:path];

//获取省份的，将取出来的省份数据放在省的可变集合Statearry里

for (NSDictionary *arr in self.arry)

{

[self.Statearry addObject:arr[@"State"]];

}

//创建pickView

self.pickView=[[UIPickerView alloc] initWithFrame:CGRectMake(0, 200, 414, 200)];

self.pickView.backgroundColor=[UIColor grayColor];

self.pickView.delegate=self;

self.pickView.dataSource=self;

[self.view addSubview:self.pickView];

}

#pragma mark 数据源 Method numberOfComponentsInPickerView

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView

{

//两列

return 2;

}

#pragma mark 数据源 Method pickerViewOfRows

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component

{

if (component==0)

{

//省份的个数

return self.Statearry.count;

}

else

{

//市的个数

return self.Citiesarry.count;

}

}

#pragma mark delegate 显示信息的方法

-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component

{

if (component==0)

{

//选择的省份

return self.Statearry[row];

}

else

{

//选择的市

return self.Citiesarry[row];

}

}

#pragma mark 选中行的信息

-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component

{

if (component==0)

{

//清空上一次市的那一列留下来的数据

[self.Citiesarry removeAllObjects];

//定义一个index，找出第一个滚动条里面的所有省对应的下标找出来，赋值给index

NSInteger index=[pickerView selectedRowInComponent:0];

//遍历出所有市

for (NSDictionary *city in self.arry[index][@"Cities"])

{

//将遍历出来市追加到存放市的集合里

[self.Citiesarry addObject:city[@"city"]];

}

//        NSLog(@"%@",self.Citiesarry);

//更新第二个滚轮的数据

[self.pickView reloadComponent:1];

}

else

{

//显示取出来的省和市

NSString *message=[NSString stringWithFormat:@"你选择的是%@的%@?",self.Statearry[[pickerView selectedRowInComponent:0]],self.Citiesarry[row]];

//设置弹出框的标题

UIAlertController *alert=[UIAlertController alertControllerWithTitle:@"提示" message:message preferredStyle:UIAlertControllerStyleAlert];

//设置按钮名称

UIAlertAction *okAction=[UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {

}];

//设置按钮名称

UIAlertAction *cancelAction=[UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:nil];

//将按钮加到提示框里面

[alert addAction:okAction];

[alert addAction:cancelAction];

//

[self presentViewController:alert animated:YES completion:nil];

}

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end