public async Task <string> GetStringByImageAsync(string imgbase64string, string url) { var tmpurl = string.IsNullOrEmpty(url) ? string.Empty : url.Contains("http://") ? url : "http://" + url; var PostData = new Dictionary <string, object> { ["image"] = imgbase64string, ["url"] = tmpurl, //["language_type"] = "CHN_ENG", //["detect_direction"] = "true", //["probability"] = "true", }; var par = new RequestParam { Url = Url, HttpMethod = HttpMethod.Post, Params = new Dictionary <string, object>() { ["access_token"] = Token, }, MediaTypeHeaderValue = ContentType.CreateFormUrlencoded(), //Encoding=Encoding.Default }; if (string.IsNullOrEmpty(imgbase64string) && !string.IsNullOrEmpty(tmpurl)) { PostData.Remove("image"); } else if (!string.IsNullOrEmpty(imgbase64string) && string.IsNullOrEmpty(tmpurl)) { PostData.Remove("url"); } else { PostData.Remove("url"); } var data = string.Join("&", RequstsHelper.DicToEnumerableKeyPairEncode(PostData).Select(x => x.Key + "=" + x.Value)); par.SendData = Encoding.UTF8.GetBytes(data); using (var res = await Session.SendAsync(par)) { var html = await res.ReadAsStringAsync(); return(html); //return JsonConvert.DeserializeObject<JObject>(html); } //return Task.FromResult("222"); }