C# 调用腾讯即时通信 IM

im sdk api 概述 https://cloud.tencent.com/document/product/269/33543

        /// <summary>
        /// im sdk 初始化。
        /// </summary>
        /// <param name="sdk_app_id"></param>
        /// <param name="json_sdk_config"></param>
        /// <returns></returns>
        [dllimport(@"imsdk.dll", callingconvention = callingconvention.cdecl, charset = charset.ansi)]
        public extern static int timinit(long sdk_app_id, string json_sdk_config);

        /// <summary>
        /// 登录
        /// </summary>
        /// <param name="user_id">用户id</param>
        /// <param name="user_sig">签名</param>
        /// <param name="cb"></param>
        /// <returns></returns>
        [dllimport(@"imsdk.dll", callingconvention = callingconvention.cdecl)]
        private extern static int timlogin(string user_id, string user_sig, timcommcallback cb);

        /// <summary>
        /// 接收新消息回调
        /// </summary>
        /// <param name="cb"></param>
        [dllimport(@"imsdk.dll", callingconvention = callingconvention.cdecl, charset = charset.ansi)]
        private extern static void timaddrecvnewmsgcallback(delegatetimrecvnewmsgcallback cb);

        public void iminit()
        {
            int sdk_app_id = 1400000000;
            var data = new { sdk_config_log_file_path = appdomain.currentdomain.basedirectory, sdk_config_config_file_path = appdomain.currentdomain.basedirectory };
            timinit(sdk_app_id, jsonconvert.serializeobject(data));
            timaddrecvnewmsgcallback(timrecvnewmsgcallback);
            var tlssig = new tlssigapiv2(sdk_app_id, "163250645178b565ffc0b22618d14a88d8a91d86f0e76813313197a5xxxxxxx");
            timlogin("用户", tlssig.gensig("用户"), commcallback);

        }
        private delegate int timcommcallback(int code, string desc, string json_params);
        
        private int commcallback(int code, string desc, string json_params)
        {
            return code;
        }
        private delegate void delegatetimrecvnewmsgcallback(string json_msg_array,intptr user_data);
        private  void timrecvnewmsgcallback(string json_msg_array, intptr user_data) {
            var b = encoding.default.getbytes(json_msg_array);
            richtextbox1.appendtext(encoding.utf8.getstring(b));
        }

        private void form1_load(object sender, eventargs e)
        {
          iminit();
        }