reactToMessage method

Future<Map<String, dynamic>> reactToMessage({ required String fromUserId, required String emoji, String? toUserId, String? groupId, String? targetClientMsgId, int targetSeq = 0, String? targetSenderId, bool add = true, })

对一条消息加 / 取消表情回应。POST /api/user/im/reaction。

服务端以 Custom(110) 消息发出（data 里 sy=reaction_lite），对端按普通自定义消息收到， 用 SyImReaction.parse 解析。不是 OpenIM 原生回应接口，也没有服务端聚合计数。 单聊传 toUserId，群聊传 groupId；目标消息用 targetClientMsgId 或 targetSeq。

Implementation

Future<Map<String, dynamic>> reactToMessage({
  required String fromUserId,
  required String emoji,
  String? toUserId,
  String? groupId,
  String? targetClientMsgId,
  int targetSeq = 0,
  String? targetSenderId,
  bool add = true,
}) =>
    _userPost(
      '/api/user/im/reaction',
      SyImReaction.requestBody(
        appId: appId,
        fromUserId: fromUserId,
        emoji: emoji,
        toUserId: toUserId,
        groupId: groupId,
        targetClientMsgId: targetClientMsgId,
        targetSeq: targetSeq,
        targetSenderId: targetSenderId,
        add: add,
      ),
    );