1、比如在使用Post請求，引數使用raw方式的時候，我們可以設定請求頭解決問題。

AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
manager.securityPolicy = [AFSecurityPolicy policyWithPinningMode:AFSSLPinningModeNone];
manager.responseSerializer = [AFJSONResponseSerializer serializer];
manager.requestSerializer = [AFJSONRequestSerializer serializer];
[manager.requestSerializer setValue:@"application/json" forHTTPHeaderField:@"Accept"];
[manager.requestSerializer setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];