这是一篇AFNetworking的详细解析

使用示例

新建一个AFHTTPSessionManager的manager，然后用manager请求对应网址的信息，回调会调用success的completionHander代码块。

AFHTTPSessionManager* manager = [AFHTTPSessionManager manager];
[manager GET:@"www.baidu.com" 
parameters:nil 
progress:nil 
success:^(NSURLSessionDataTask * _Nonnull task,
id  _Nullable responseObject) {
        NSLog(responseObject);
    } failure:nil];

AFNetworking流程图

Paste_Image.png

• 调用post请求

- (NSURLSessionDataTask *)POST:(NSString *)URLString parameters:(id)parameters 
progress:(void (^)(NSProgress * _Nonnull))uploadProgress 
success:(void (^)(NSURLSessionDataTask * _Nonnull, id _Nullable))success 
failure:(void (^)(NSURLSessionDataTask * _Nullable,
 NSError * _Nonnull))failure

• 新建一个task

- (NSURLSessionDataTask *)dataTaskWithHTTPMethod:(NSString *)method 
URLString:(NSString *)URLString 
parameters:(id)parameters 
uploadProgress:(nullable void (^)(NSProgress *uploadProgress)) uploadProgress 
downloadProgress:(nullable void (^)(NSProgress *downloadProgress)) 
downloadProgress 
success:(void (^)(NSURLSessionDataTask *, id))success 
failure:(void (^)(NSURLSessionDataTask *, NSError *))failure

• 新建一个request

- (NSMutableURLRequest *)requestWithMethod:(NSString *)method 
URLString:(NSString *)URLString 
parameters:(id)parameters 
error:(NSError *__autoreleasing *)error

• 新建一个dataTask

- (NSURLSessionDataTask *)dataTaskWithRequest:(NSURLRequest *)request 
uploadProgress:(nullable void (^)(NSProgress *uploadProgress)) 
uploadProgressBlock downloadProgress:(nullable void (^)(NSProgress *downloadProgress)) 
downloadProgressBlock 
completionHandler:(nullable void (^)(NSURLResponse *response, id _Nullable responseObject
, NSError * _Nullable error))completionHandler

• 添加delegate

- (void)addDelegateForDataTask:(NSURLSessionDataTask *)dataTask 
uploadProgress:(nullable void (^)(NSProgress *uploadProgress)) 
uploadProgressBlock downloadProgress:(nullable void (^)(NSProgress *downloadProgress)) 
downloadProgressBlock 
completionHandler:(void (^)(NSURLResponse *response
, id responseObject, NSError *error))completionHandler

整体架构

• AFURLSessionManager的mutableTaskDelegatesKeyedByTaskIdentifier属性，存放着每一个task对应的AFURLSessionManagerTaskDelegate；
• AFURLSessionManager的NSURLSessionDelegate实现，会调用每个task对应的AFURLSessionManagerTaskDelegate；
• 设置Task的AFURLSessionManagerTaskDelegate时，用了NSLock，进行多线程同步；
• 任务的调度采用了工厂模式、观察者和代理模式。
  • 工厂模式
    对于HTTP协议的请求有
    AFHTTPRequestSerializer
    AFJSONRequestSerializer
    AFPropertyListRequestSerializer
    三个都依赖抽象接口AFURLRequestSerialization
    对于HTTP协议的响应有
    AFHTTPResponseSerializer
    AFJSONResponseSerializer
    AFXMLParserResponseSerializer
    AFXMLDocumentResponseSerializer
    AFPropertyListResponseSerializer
    AFImageResponseSerializer
    AFCompoundResponseSerializer
    都依赖抽象接口 AFURLResponseSerialization
    符合 开放-封闭原则
    对增加新的请求头、响应头是开放的，而且增加新内容不需要修改原内容
  • 观察者模式
    对于task的每个生命周期，都会有相应的事件发出
    AFNetworkingTaskDidResumeNotification
    AFNetworkingTaskDidSuspendNotification
    对于task用KVO的方式去监听Progress
  • 代理模式
    AFURLSessionManagerTaskDelegate 是AF对自己的逻辑封装，同时实现了
    NSURLSessionTaskDelegate,
    NSURLSessionDataDelegate
    NSURLSessionDownloadDelegate
    同时通过实现NSURLSessionDelegate，来接受session级别的事件。