Retrieve members who have read a message

Using the GetReadMembers() method, you can view members who have read a specific message in a group channel. The method returns a list of channel members who have read the message by comparing the message's creation time and the channel members' read receipt. The list excludes the current user and the message sender.

Note: Read receipt indicates the timestamp of the latest time when each user has read messages in the channel in Unix milliseconds.

If you want real-time updates on who has read a new message, use the OnReadStatusUpdated() event handler for the client app to receive a callback from the Sendbird server whenever a channel member reads a message.

SbGroupChannelHandler groupChannelHandler = new SbGroupChannelHandler
{
    OnReadStatusUpdated = (inGroupChannel) => 
    {
        // Handle the read status update here.
    }
};

SendbirdChat.GroupChannel.AddGroupChannelHandler(UNIQUE_HANDLER_ID, groupChannelHandler);

Note: Using the GetUnreadMembers() method, you can also view members who haven't read a specific message in a group channel, except the current user and the message sender.