8.网络请求（未完）

一、前言：工程是MVC的,采用AFNetworking框架进行网络数据请求
MBProgressHUD框架进行弹窗提示

二、定义网络请求
1.直接在Model层定义一个类
例如DCCardModel

#import 

@interface DCCardModel : NSObject
@property(nonatomic,copy)NSString *update;//
@property(nonatomic,copy)NSString *url;
 
//定义两种方法
+ (NSURLSessionDataTask *)queryCardWithParameters:(NSDictionary *)parameters completion:(responseArrayWithPaginationBlock)completion;

+ (void)loadCardCompletion:(responseArrayBlock)completion;
@end

属性解释
因为发起POST请求：返回结果是{"update":"2","url":"http://s16.sinaimg.cn/large/005vePOgzy70Rd3a9pJdf&690"}
上面的属性就是根据这个定义的

方法解释：

• (void)loadCardCompletion:(responseArrayBlock)completion;

首先它是一个类方法，responseArrayBlock是一个Block，这个Block定义在一个公共的文件，例如AppConfig.h定义
typedef void (^responseArrayBlock)(NSArray *array, NSString *error);

---

方法实现

+ (void)loadCardCompletion:(responseArrayBlock)completion
{
 
    [[APIClient sharedClient] POST:@"http://127.0.0.1/getJson.php"
                        parameters:nil
                          progress:^(NSProgress * _Nonnull uploadProgress) {
                              
                          } success:^(NSURLSessionDataTask * _Nonnull task, id  _Nullable responseObject) {
                            
                              NSLog(@"请求结果：%@",responseObject);
                              //block回调
                               completion(nil,data);
                          } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
                              completion(nil, error.localizedDescription);
                          }];
}

[[APIClient sharedClient] 是对Afnetwork的封装方法

在APIClient.h类中定义一个请求单例

• (instancetype)sharedClient;
  .m实现

+ (instancetype)sharedClient {
    static APIClient *_sharedClient = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        _sharedClient = [APIClient manager];
        _sharedClient.requestSerializer = [AFJSONRequestSerializer serializer];
        _sharedClient.responseSerializer = [ResponseSerializer serializer];
        //设定请求超时时间
        [_sharedClient.requestSerializer willChangeValueForKey:@"timeoutInterval"];
        _sharedClient.requestSerializer.timeoutInterval = 60.f;
        [_sharedClient.requestSerializer didChangeValueForKey:@"timeoutInterval"];
        ((AFJSONResponseSerializer *)_sharedClient.responseSerializer).removesKeysWithNullValues = YES;
        _sharedClient.responseSerializer.acceptableContentTypes = [NSSet setWithObjects:@"application/json", @"text/json", @"text/html", @"text/javascript", @"text/plain", nil];

    });
    return _sharedClient;
}

---

三、使用
viewController.m定义一个方法，加载数据

#pragma mark - 请求卡类型数据
- (void)loadData
{
    //先走一个动画，提示用户正在加载数据
    [MBProgressHUD showCustomLoadingHub:[MBProgressHUDCoustomView hotelLoadingGifView]];
    
    @weakify(self);
    [DCCardModel loadCardCompletion:^(NSArray *array, NSString *error) {
        @strongify(self)
        //请求到数据的时候，就隐藏动画
        [MBProgressHUD hideHUD];
        if (!error) {
            if (array.count > 0) {
                NSLog(@"do something!!!!!!!!!!");
            }
        } else {
            [MBProgressHUD showHUDWithFailedText:error];
        }
  
    }];
    
}