public static Stream Get(string access_token, MediaType type, string mediaId) { if (type == MediaType.News) { throw new NotSupportedException("图文信息请使用GetNews获取"); } else if (type == MediaType.Video) { throw new NotSupportedException("下载视频请使用MaterialVideoDownloadUrl获取下载地址"); } else { return(HttpClientExtensions.PostData(ApiUrl("/cgi-bin/material/get_material?access_token={0}", access_token), "{\"media_id\":\"" + mediaId + "\"}", mediaType: "application/json")); } }