#pragma mark - 网络请求代理方式（异步）  - (IBAction)DelegateButtonDidClicked:(UIButton *)sender {        // 1、拼接 urlString,网址里面必须写 http://      NSString *urlString = @"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx?date=20131129&startRecord=1&len=5&udid=1234567890&terminalType=Iphone&cid=213";        // 2、根据字符串创建 URL(统一资源定位符)      NSURL *url = [NSURL URLWithString:urlString];        // 3、根据 url 创建 request 请求类的对象      NSURLRequest *request = [NSURLRequest requestWithURL:url];        // 4、请求数据（代理回调方式）遵守代理 <NSURLConnectionDataDelegate>      [NSURLConnection connectionWithRequest:request delegate:self];  }

代理方法
客户端收到服务器的响应

#pragma mark | 客户端收到服务器的响应  - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response  {      // 只执行一次      // 初始化 receiveData 对象      self.receiveData = [NSMutableData data];  }

客户端收数据(并非一次性全部拿到)

#pragma mark | 客户端收数据(并非一次性全部拿到)  - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data  {      // 每次返回的都是新数据      // 拼接数据(请求一点 拼接一点)      [self.receiveData appendData:data];  }

客户端接收数据完毕

#pragma mark | 客户端接收数据完毕  - (void)connectionDidFinishLoading:(NSURLConnection *)connection  {      // 解析数据      NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:self.receiveData options:(NSJSONReadingMutableContainers) error:nil];          NSArray *array = dict[@"news"];        self.newsArray = [NSMutableArray array];        for (NSDictionary *smallDict in array) {          NewsModal *modal = [[NewsModal alloc] init];          [modal setValuesForKeysWithDictionary:smallDict];          [self.newsArray addObject:modal];      }        for (NewsModal *modal in self.newsArray) {          NSLog(@"%@", modal.title);      }  }

网络请求失败

#pragma mark | 网络请求失败  - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error  {      NSLog(@"%@", error);  }