AFNetworking 撤消请求

取消单个操作：

AFHTTPRequestOperation *operation= [[AFHTTPRequestOperation alloc] initWithRequest:request];

[operation cancel];

或者

AFHTTPRequestOperation *operation = [postManager POST:request.methodUrlparameters:parameterssuccess:^(AFHTTPRequestOperation *operation,id responseObject) {}failure:^(AFHTTPRequestOperation *operation,NSError *error){}];[operation cancel];

取消所有操作：

AFHTTPRequestOperationManager *httpmanager = [AFHTTPRequestOperationManager manager];

[httpManager.operationQueue cancelAllOperations];