tencent cloud

var message = new Message
{
   message_conv_id = conv_id,
   message_conv_type = TIMConvType.kTIMConv_Group,
   message_elem_array = new List<Elem>{new Elem
   {
     elem_type = TIMElemType.kTIMElem_Text,
     text_elem_content = Input.text
   }},
   message_target_group_member_array = userid_list, // Specify the list of `UserID` values of group members to receive the message
};
StringBuilder messageId = new StringBuilder(128);
TIMResult res = TencentIMSDK.MsgSendMessage(conv_id, TIMConvType.kTIMConv_Group, message, messageId, (int code, string desc, string json_param, string user_data)=>{
 // Async message sending result
});