显示天气预报的Demo

实现的效果如下所示:

代码如下:

ViewController.h

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController
@property (weak, nonatomic) IBOutlet UIPickerView *cityPickView;
- (IBAction)request:(id)sender;

@property (weak, nonatomic) IBOutlet UILabel *city;
@property (weak, nonatomic) IBOutlet UILabel *temperature;
@property (weak, nonatomic) IBOutlet UILabel *windyDirection;
@property (weak, nonatomic) IBOutlet UILabel *level;
@property (weak, nonatomic) IBOutlet UILabel *moisture;
@property (weak, nonatomic) IBOutlet UILabel *time;

@end

ViewController.m

#import "ViewController.h"

@interface ViewController ()

@property (nonatomic,strong)NSDictionary *dic;
@property (weak, nonatomic) IBOutlet UIView *activityView;

//@property (nonatomic,strong)UIActivityIndicatorView *activity;

//存放所有的城市名字
@property (nonatomic,strong)NSMutableArray *data;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
   
 
    //先隐藏
    _activityView.hidden = YES;
   
}

//懒加载
- (NSDictionary *)dic
{
    if (_dic == nil) {
        
        NSString *path = [[NSBundle mainBundle]pathForResource:@"cityCode.plist" ofType:nil];
        _dic = [NSDictionary dictionaryWithContentsOfFile:path];
    }
    return _dic;
    
}

- (NSMutableArray *)data
{
    if (_data == nil) {
        _data = [NSMutableArray array];
        
    }
    
    return _data;
    
}
//列数
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return 1;
    
}

//每列的行数
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    return self.dic.count;
    
}

//显示标题
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{

//取得所有的key
    NSArray *cities = [_dic allKeys];
    
    //_data保存所有的城市
    _data = [cities copy];
    
    //取得城市的名字
    NSString *cityName = cities[row];
    
    return cityName;
    
    
}

//当前选中的行数
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
    NSLog(@"row = %ld",row);
    
    
}

//请求网络数据
- (IBAction)request:(id)sender {
    
    _activityView.hidden = NO;
    
    //得到_cityPickView当前选中的行数
    NSInteger rowIndex = [_cityPickView selectedRowInComponent:0];
    
    //得到 选中行的城市名字
    NSString *city = _data[rowIndex];
    
    //取得城市对应的ID
    NSString *cityId = _dic[city];

//构造URL对象
    NSString *str = [NSString stringWithFormat:@"http://www.weather.com.cn/adat/sk/%@.html",cityId];
    
    NSURL *url = [NSURL URLWithString:str];
    
    //构造request对象
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
    
    //构造NSURLSession
    NSURLSession *session= [NSURLSession sharedSession];
    
    //创建网络任务
    NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
        
        //解析JSON数据
        NSDictionary *dic1 = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
 
        //回到主线程  刷新UI
        dispatch_async(dispatch_get_main_queue(), ^{
            
            [self refreshUI:dic1];
            
        });
        
    }];
    
    //发起网络任务
    [task resume];
}

//刷新UI
- (void)refreshUI:(NSDictionary *)dic
{
    
    _activityView.hidden = YES;
    
    //取得数据
    NSDictionary *dic2 = dic[@"weatherinfo"];
    NSString *ws = dic2[@"WS"];    //风级
    NSString *city = dic2[@"city"];    //城市
    NSString *temp = dic2[@"temp"];   //温度
    NSString *SD = dic2[@"SD"];      //湿度
    NSString *Wd = dic2[@"WD"];    //风向
    NSString *time = dic2[@"time"];  //时间

_city.text = city;
    _temperature.text = temp;
    _windyDirection.text = Wd;
    _level.text = ws;
    _moisture.text = SD;
    _time.text = time;
    
}

在以后的学习中,会一直坚持写博客,记录自己的学习笔记,为自己的学习和工作做好准备!!!