iOS 建立地区

#import "ViewController.h"

@interface ViewController ()

<UIPickerViewDataSource,UIPickerViewDelegate>

@property(nonatomic,strong)UIPickerView *pickerView;

@property(nonatomic,strong)NSArray *rowDataSource;

@property(nonatomic,strong)NSArray *row2DataSource;

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    self.rowDataSource=@[@"安徽省",@"浙江省",@"山东省",@"江苏省",@"陕西省",@"福建省",@"湖北省",@"湖南省"];

     self.row2DataSource=@[@"芜湖市",@"合肥市",@"南京市",@"杭州市",@"广东市",@"亳州市",@"自贡市",@"长沙市"];

    self.pickerView=[[UIPickerView alloc]initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width,400)];

    //UIPickerView  选择的数据必须提供，可以有多列数据，  每一列有多行数据

    self.pickerView.dataSource=self;

    self.pickerView.delegate=self;

    [self.viewaddSubview:self.pickerView];

}

//列数

-(NSInteger)numberOfComponentsInPickerView:(nonnullUIPickerView*)pickerView

{

    return 2;

}

//每一列的行数

-(NSInteger)pickerView:(nonnullUIPickerView*)pickerView numberOfRowsInComponent:(NSInteger)component{

  NSIntegercount  =0;

if(component ==0)

{

    return self.rowDataSource.count;

}

elseif(component ==1)

{

    count =self.row2DataSource.count;

}

    returncount;

}

//每一行的数据

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

    NSString* title =@"";

    if(component ==0)

    {

        title=self.rowDataSource[row];

    }

    elseif(component ==1)

    {

        title =self.row2DataSource[row];

    }

    returntitle;

}

- (void)didReceiveMemoryWarning {

    [super didReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}

@end