// Call the markAsRead method when the current user views// unread messages in a group channel.
channel.markAsRead { error inguard error ==nilelse{// Handle error.return}}// To listen to an update from other channel members' client apps,// implement the channelDidUpdateReadStatus(_:) function// with actions to perform when notified.classGroupChannelChattingViewController:UIViewController,GroupChannelDelegate{funcinitViewController(){SendbirdChat.add(selfasGroupChannelDelegate, identifier:UNIQUE_DELEGATE_ID)}funcchannelDidUpdateReadStatus(_ channel:GroupChannel){if currentGroupChannel.channelURL == channel.channelURL {for msg in messages {let unreadCount = channel.getUnreadMemberCount(msg)if unreadCount <=0{// All members have read the message.}else{// Some of members haven't read the message.}}}}}