.net core API 微信上傳圖片接口的實現 media data missing hint

API：https://api.weixin.qq.com/cgi-bin/media/uploadimg?access_token=ACCESS_TOKEN

代碼實現

		/// <summary>
		/// 上傳圖片素材
		/// </summary>
		/// <param name="access_token">公衆號token</param>
		/// <param name="buffer">文件的數據流</param>
		/// <param name="FileName">文件名</param>
		/// <returns></returns>
		public async Task<Entity.RetModels.Retmsg> Senduploadimg(string access_token, Stream buffer,string FileName)
		{
		// 接口
			string APIStr = ConfigHelp.ConfigHelper.GetSectionValue("WechatAPI:Get_API_weixin:Senduploadimg");
			// 拼接API
			string APIUrl = string.Format("{0}?access_token={1}", APIStr, access_token);
			var formdata = new MultipartFormDataContent();
			formdata.Headers.ContentType = new MediaTypeHeaderValue("multipart/form-data");
			// formdata.Add(new StringContent(access_token), "access_token");
			formdata.Add(new StreamContent(buffer), "buffer", "\"" + FileName +"\"");

			var response = await _Client.PostAsync(APIUrl, formdata);
			string RetJson = await response.Content.ReadAsStringAsync();//獲取返回的Json字符串
			// 
			}

	formdata.Add(new StreamContent(buffer), "buffer", "\"" + FileName +"\"");
	大佬能解釋下爲啥要加上\“,卡了我一天

得到了想要的結果

參考資料