block做方法参数时--block的参数传值过程 例1

说明：此例子中方法的调用在此文中是从下到上调用的。(即：     方法五调用方法四；      方法四调用方法三)

方法一：
- (void)setCompletionBlockWithSuccess:(void (^)(AFHTTPRequestOperation *operation, id responseObject))success
                              failure:(void (^)(AFHTTPRequestOperation *operation, NSError *error))failure
{
    // completionBlock is manually nilled out in AFURLConnectionOperation to break the retain cycle.
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-retain-cycles"
#pragma clang diagnostic ignored "-Wgnu"
    self.completionBlock = ^{
        if (self.completionGroup) {
            dispatch_group_enter(self.completionGroup);
        }

        dispatch_async(http_request_operation_processing_queue(), ^{
            if (self.error) {
                if (failure) {
                    dispatch_group_async(self.completionGroup ?: http_request_operation_completion_group(), self.completionQueue ?: dispatch_get_main_queue(), ^{
                        failure(self, self.error);
                    });
                }
            } else {
                id responseObject = self.responseObject; // self.responseObject 是本方法所在文件中的一个属性
                if (self.error) {
                    if (failure) {
                        dispatch_group_async(self.completionGroup ?: http_request_operation_completion_group(), self.completionQueue ?: dispatch_get_main_queue(), ^{
                            failure(self, self.error);
                        });
                    }
                } else {
                    if (success) {
                        dispatch_group_async(self.completionGroup ?: http_request_operation_completion_group(), self.completionQueue ?: dispatch_get_main_queue(), ^{
                            success(self, responseObject);
                        });
                    }
                }
            }

            if (self.completionGroup) {
                dispatch_group_leave(self.completionGroup);
            }
        });
    };
#pragma clang diagnostic pop
}

方法二、
- (AFHTTPRequestOperation *)HTTPRequestOperationWithRequest:(NSURLRequest *)request
                                                    success:(void (^)(AFHTTPRequestOperation *operation, id responseObject))success
                                                    failure:(void (^)(AFHTTPRequestOperation *operation, NSError *error))failure
{
    AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
    operation.responseSerializer = self.responseSerializer;
    operation.shouldUseCredentialStorage = self.shouldUseCredentialStorage;
    operation.credential = self.credential;
    operation.securityPolicy = self.securityPolicy;

    [operation setCompletionBlockWithSuccess:success failure:failure];
    operation.completionQueue = self.completionQueue;
    operation.completionGroup = self.completionGroup;

    return operation;
}

方法三、
- (AFHTTPRequestOperation *)HTTPRequestOperationWithHTTPMethod:(NSString *)method
                                                     URLString:(NSString *)URLString
                                                    parameters:(id)parameters
                                                       success:(void (^)(AFHTTPRequestOperation *operation, id responseObject))success
                                                       failure:(void (^)(AFHTTPRequestOperation *operation, NSError *error))failure
{
    NSError *serializationError = nil;
    NSMutableURLRequest *request = [self.requestSerializer requestWithMethod:method URLString:[[NSURL URLWithString:URLString relativeToURL:self.baseURL] absoluteString] parameters:parameters error:&serializationError];
    if (serializationError) {
        if (failure) {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wgnu"
            dispatch_async(self.completionQueue ?: dispatch_get_main_queue(), ^{
                failure(nil, serializationError);
            });
#pragma clang diagnostic pop
        }

        return nil;
    }

    return [self HTTPRequestOperationWithRequest:request success:success failure:failure];
}

方法四、

- (AFHTTPRequestOperation *)POST:(NSString *)URLString
                      parameters:(id)parameters
                         success:(void (^)(AFHTTPRequestOperation *operation, id responseObject))success
                         failure:(void (^)(AFHTTPRequestOperation *operation, NSError *error))failure
{
    AFHTTPRequestOperation *operation = [self HTTPRequestOperationWithHTTPMethod:@"POST" URLString:URLString parameters:parameters success:success failure:failure];

    [self.operationQueue addOperation:operation];

    return operation;
}

方法五、     注：typedef void(^HttpRequestSuccess)(HDXHttpRequestManager* manager,id model);

#pragma mark - 食府搜索
-(void)RestaurantListWithKeyWord:(NSString *)keyword Lat:(CGFloat)lat Lng:(CGFloat)lng Success:(HttpRequestSuccess)success Fail:(HttpRequestFail)fail
{
    NSDictionary *dic=@{@"keyword":keyword,@"lat":[NSNumber numberWithFloat:lat],@"lng":[NSNumber numberWithFloat:lng]};
    AFHTTPRequestOperationManager *manager=[AFHTTPRequestOperationManager manager];
    
    [manager POST:[BaseURL stringByAppendingString:@"foods/list.json"] parameters:[self getParams:dic] success:^(AFHTTPRequestOperation *operation, id responseObject) {
        success(self,responseObject);
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        fail(self, error);
    }];
   
}

方法六、

-(void)SearchReastaurant
{
    HDXHttpRequestManager *manager=[HDXHttpRequestManager shareManager];
    
    [manager RestaurantListWithKeyWord:_searchBar.text Lat:Lat Lng:Lng Success:^(HDXHttpRequestManager *manager, id model) {
        DLog(@"====搜索出来的几家食府=数据=%@",model);
        if ([model[@"code"] isEqualToNumber:@(200)]) {

            [mapview removeAnnotations:annotationAry];
            [annotationAry removeAllObjects];

            for (NSDictionary *dic in model[@"data"]) {
                ModelRestaurantList *listModel=[[ModelRestaurantList alloc]initWithDictionary:dic];
                HDXPointAnnotation *annotation=[[HDXPointAnnotation alloc] init];
                annotation.title=listModel.restaurantName;
//                annotation.subtitle=listModel.address;
                annotation.coordinate=CLLocationCoordinate2DMake(listModel.lat, listModel.lng);
                annotation.ID=listModel.ID;
                [annotationAry addObject:annotation];
                
            }
            if (annotationAry.count>0) {
                [mapview addAnnotations:annotationAry];
            }
            else{
                [MBProgressHUD showMessage:@"对不起，没有找到您需要的食府" toView:nil];
            }
        }
    } Fail:^(HDXHttpRequestManager *manager, id model) {
        DLog(@"%@",model);
    }];
}

相当于 A 调 B、 B 调用 C、C 调用 D。

在 A 里面调用 B 的时候顺便 实现 B 方法的 block 回调方法 ( B方法参数其中有一个是一个block类型的参数 )，B方法里面会调用 B 方法的参数的block变量 (相当于拿到函数指针做调用)