GZip提升响应速度，减少文件的大小
gzip level （1~9）压缩比

    AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    manager.requestSerializer =  [AFHTTPRequestSerializer serializer];
    manager.responseSerializer =  [AFHTTPResponseSerializer serializer];
    manager.requestSerializer.timeoutInterval = 10;//请求超时
    manager.requestSerializer.cachePolicy = NSURLRequestUseProtocolCachePolicy; //缓存策略
    [manager.requestSerializer setValue:@"gzip" forHTTPHeaderField:@"Content-Encoding"];
    [manager.requestSerializer setValue:@"gzip" forHTTPHeaderField:@"Accept-Content"];
    manager.responseSerializer.acceptableContentTypes =  [NSSet setWithObjects:@"application/json;charset=utf-8", @"text/json", @"text/javascript", @"text/plain",@"text/html",@"application/json", nil];
    manager.responseSerializer.acceptableContentTypes = [NSSet setWithObjects:@"application/json",@"text/json", @"text/plain", @"text/html", nil];

• 对后台GZip返回的加密后的字符串进行解密

  
  
  WechatIMG1.jpeg
• 例子：(前端进行对数据用GZip加密然后再解密)
  
  WechatIMG2.jpeg
  
  GZip网络链接