ios之自动拾取器

//

//  ViewController.m

//  自动拾取器

//

//  Created by 李江 on 16/5/4.

//  Copyright © 2016年 李江. All rights reserved.

//

#import "ViewController.h"

#import "MJExtension.h"

#import "CityModel.h"

@interface ViewController ()<UIPickerViewDataSource,UIPickerViewDelegate>

{

    NSArray *dataArray;

   

}

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    UIPickerView *pickerView = [[UIPickerView alloc]initWithFrame:CGRectMake(0, 736-300, 414, 300)];

    pickerView.delegate  =self;

    pickerView.dataSource = self;

    pickerView.backgroundColor = [UIColor grayColor];

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

    dataArray = [NSArray arrayWithContentsOfFile:path];

    //把数据类型转化为CityModel

    NSLog(@"%@",dataArray);

    dataArray = [CityModel mj_objectArrayWithKeyValuesArray:dataArray];

    [self.view addSubview:pickerView];

}

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{

    return 2;

}

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

    if (component == 0) {

        return dataArray.count;

    }

    NSInteger selectRow = [pickerView selectedRowInComponent:component];

    CityModel *model = dataArray[selectRow];

    NSArray *cityArray = model.cities;

    return cityArray.count;

}

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

    if (component == 0) {

        CityModel *model = dataArray[row];

        return model.state;

    }

    NSInteger selectedRow = [pickerView selectedRowInComponent:0];

    CityModel *model = dataArray[selectedRow];

    return model.cities[row];

}

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

    if (component == 0) {

        [pickerView reloadAllComponents];

    }

}

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CityModel.h里面代码如下

@property(nonatomic,copy)NSArray *cities;

@property(nonatomic,copy)NSString *state;

plist文件格式

运行效果