1、比如在使用Post请求，参数使用raw方式的时候，我们可以设置请求头解决问题。
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"];