根据Mob官网的天气预报接口写了一个简单的demo

第一步 自己注册一个应用，然后获取里面的 App Key，下载MobAPI SDK

然后拖入 MobAPI.framework 和 MOBFoundation.framework 到你的项目中

官网是 ：http://www.mob.com

第二步  导入libraries  文件

第三步 ：  新建一个 UIViewController 控制器  －－－ WeatherMainViewController

然后在  AppDelegate.m 里面写入如下  要导入

#import "WeatherMainViewController.h"

#import <MobAPI/MobAPI.h>

 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
     self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
     self.window.backgroundColor = [UIColor whiteColor];
     // 1. 首页
     WeatherMainViewController *weather = [[WeatherMainViewController alloc] init ];
     self.window.rootViewController = weather;
     [self.window makeKeyAndVisible];
 
     [MobAPI registerApp:@"1ab37d5dsa3a3c"];
     return YES;
 }

注意： 1ab37d5dsa3a3c 是你的 App Key

第四：根据api文档获取里面的字段和返回参数取值

他的返回参数是

                             {
   "msg": "success",
   "result": [
     {
       "airCondition": "良",
       "city": "北京",
       "coldIndex": "低发期",
       "updateTime": "",
       "date": "2015-09-08",
       "distrct": "门头沟",
       "dressingIndex": "短袖类",
       "exerciseIndex": "适宜",
       "future": [
         {
           "date": "2015-09-09",
           "dayTime": "阵雨",
           "night": "阴",
           "temperature": "24°C/18°C",
           "week": "星期三",
           "wind": "无持续风向小于3级"
         },
         {
           "date": "2015-09-10",
           "dayTime": "阵雨",
           "night": "阵雨",
           "temperature": "22°C/15°C",
           "week": "星期四",
           "wind": "无持续风向小于3级"
         },
         {
           "date": "2015-09-11",
           "dayTime": "阴",
           "night": "晴",
           "temperature": "23°C/15°C",
           "week": "星期五",
           "wind": "北风3～4级无持续风向小于3级"
         },
         {
           "date": "2015-09-12",
           "dayTime": "晴",
           "night": "晴",
           "temperature": "26°C/13°C",
           "week": "星期六",
           "wind": "北风3～4级无持续风向小于3级"
         },
         {
           "date": "2015-09-13",
           "dayTime": "晴",
           "night": "晴",
           "temperature": "27°C/16°C",
           "week": "星期日",
           "wind": "无持续风向小于3级"
         },
         {
           "date": "2015-09-14",
           "dayTime": "晴",
           "night": "多云",
           "temperature": "27°C/16°C",
           "week": "星期一",
           "wind": "无持续风向小于3级"
         },
         {
           "date": "2015-09-15",
           "dayTime": "少云",
           "night": "晴",
           "temperature": "26°C/14°C",
           "week": "星期二",
           "wind": "南风3级南风2级"
         },
         {
           "date": "2015-09-16",
           "dayTime": "局部多云",
           "night": "少云",
           "temperature": "26°C/15°C",
           "week": "星期三",
           "wind": "南风3级南风2级"
         },
         {
           "date": "2015-09-17",
           "dayTime": "阴天",
           "night": "局部多云",
           "temperature": "26°C/15°C",
           "week": "星期四",
           "wind": "东南风2级"
         }
       ],
       "humidity": "湿度：46%",
       "province": "北京",
       "sunset": "18:37",
       "sunrise": "05:49",
       "temperature": "25℃",
       "time": "14:35",
       "washIndex": "不适宜",
       "weather": "多云",
       "week": "周二",
       "wind": "南风2级"
     }
   ],
   "retCode": ""
 }

最后：

 //
 //  WeatherMainViewController.m
 //  全球天气预报
 //
 //  Created by txbydev3 on 17/1/11.
 //  Copyright © 2017年 陈竹青. All rights reserved.
 //
 
 //屏幕的宽度
 #define TXBYApplicationW ([UIScreen mainScreen].applicationFrame.size.width)
 //屏幕的高度
 #define TXBYApplicationH ([UIScreen mainScreen].applicationFrame.size.height)
 
 #import "WeatherMainViewController.h"
 #import "WeatherViewController.h"
 #import "Weather.h"
 #import "FutureWeather.h"
 #import "MJExtension.h"
 #import <MobAPI/MobAPI.h>
 #import <MOBFoundation/MOBFoundation.h>
 
 @interface WeatherMainViewController ()<UITableViewDelegate,UITableViewDataSource>
 
 @property (nonatomic, strong) NSArray *resultArray;
 @property (nonatomic, strong) NSArray *futureArray;
 
 @property (nonatomic, strong)  Weather *weather;
 
 @property (nonatomic, strong) UITableView *tableView ;
 
 @property (weak, nonatomic)   UILabel *city;
 @property (weak, nonatomic)   UILabel *airCondition;
 @property (weak, nonatomic)   UILabel *temperature;
 @property (weak, nonatomic)   UILabel *weatherLab;
 
 @end
 
 @implementation WeatherMainViewController
 
 - (void)viewDidLoad {
     [super viewDidLoad];
     [self request ];
 }
 
 - (void)setHeadView {
     UIImageView *imageView = [[UIImageView alloc] initWithFrame:self.view.bounds];
     imageView.image = [UIImage imageNamed:@"background"];
     [self.view addSubview:imageView];
      // 城市
     UILabel *cityLabel = [[UILabel alloc] initWithFrame:CGRectMake((TXBYApplicationW - )*0.5, , , )];
     cityLabel.textColor = [UIColor whiteColor];
     cityLabel.font = [UIFont systemFontOfSize:];
     [imageView addSubview:cityLabel];
     self.city = cityLabel;
 
     // 空气指数
     UILabel *air = [[UILabel alloc] initWithFrame:CGRectMake(, CGRectGetMaxY(cityLabel.frame) + , , )];
     air.textColor = [UIColor whiteColor];
         air.font = [UIFont systemFontOfSize:];
     air.text = @"空气指数";
     [imageView addSubview:air];
 
     UILabel *airCondition = [[UILabel alloc] initWithFrame:CGRectMake(CGRectGetMaxX(air.frame), CGRectGetMaxY(cityLabel.frame) + , TXBYApplicationW - , )];
     airCondition.textColor = [UIColor whiteColor];
         airCondition.font = [UIFont systemFontOfSize:];
     [imageView addSubview:airCondition];
     self.airCondition = airCondition;
 
 //    温度
      UILabel *temp = [[UILabel alloc] initWithFrame:CGRectMake(, CGRectGetMaxY(air.frame) + , , )];
     temp.textColor = [UIColor whiteColor];
     temp.text  =@"温度";
     temp.font = [UIFont systemFontOfSize:];
     [imageView addSubview:temp];
 
     UILabel *temperature = [[UILabel alloc] initWithFrame:CGRectMake(CGRectGetMaxX(temp.frame) , CGRectGetMaxY(airCondition.frame) + , , )];
     temperature.textColor = [UIColor whiteColor];
     temperature.font = [UIFont systemFontOfSize:];
     [imageView addSubview:temperature];
     self.temperature = temperature;
 
     // 天气
     UILabel *weatherLab = [[UILabel alloc] initWithFrame:CGRectMake(, CGRectGetMaxY(temp.frame) + , , )];
     weatherLab.textColor = [UIColor whiteColor];
     weatherLab.text  =@"天气";
     weatherLab.font = [UIFont systemFontOfSize:];
     [imageView addSubview:weatherLab];
 
     UILabel *weather = [[UILabel alloc] initWithFrame:CGRectMake(CGRectGetMaxX(weatherLab.frame), CGRectGetMaxY(temperature.frame) + , , )];
     weather.textColor = [UIColor whiteColor];
     weather.font = [UIFont systemFontOfSize:];
 //    weather.textAlignment = NSTextAlignmentCenter;
     [imageView addSubview:weather];
     self.weatherLab = weather;
 
     self.tableView = [[UITableView alloc] initWithFrame:CGRectMake(, CGRectGetMaxY(weather.frame) + , TXBYApplicationW, TXBYApplicationH *0.5) style:UITableViewStylePlain];
     self.tableView.delegate = self;
     self.tableView.dataSource = self;
     self.tableView.backgroundColor = [UIColor clearColor];
     self.tableView.tableFooterView = [UIView new];
     [imageView addSubview:self.tableView];
  }
 
 -(void)request  {
     //1.确定请求路径
    NSString *urlStr = @"http://apicloud.mob.com/v1/weather/query?key=1ab5503423a3c&city=苏州&province=江苏";
     // 防止 string 类型 转 url 为空
     urlStr = [urlStr stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];
      NSURL *url = [NSURL URLWithString:urlStr];
     NSURLRequest *request = [NSURLRequest requestWithURL:url];
      //3.获得会话对象
     NSURLSession *session = [NSURLSession sharedSession];
     NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
          if (error == nil) {
             //6.解析服务器返回的数据
             //说明：（此处返回的数据是JSON格式的，因此使用NSJSONSerialization进行反序列化处理）
             NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
              NSLog(@"%@",dict);
              [self setHeadView];
              self.resultArray = [Weather mj_objectArrayWithKeyValuesArray:dict[@"result"]];
              for (Weather *weather in self.resultArray) {
                  self.city.text = weather.city;
                  self.temperature.text = weather.temperature;
                  self.airCondition.text =weather.airCondition;
                  self.weatherLab.text =weather.weather;
                  self.futureArray = weather.future;
              }
         }
     }];
     //5.执行任务
     [dataTask resume];
 }
 
 - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
     return self.futureArray.count;
 }
 
 - (UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
     UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];
     if (cell == nil) {
         cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:@"cell"];
         cell.selectionStyle = UITableViewCellSelectionStyleNone;
         cell.backgroundColor = [UIColor clearColor];
     }
     FutureWeather *weather = self.futureArray[indexPath.row];
 
     cell.textLabel.text = weather.week;
     cell.detailTextLabel.text = weather.temperature;
     return cell;
  }
 
 - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
     return ;
 }
 
 - (void)didReceiveMemoryWarning {
     [super didReceiveMemoryWarning];
 }
 
 @end

效果图