Mute or unmute a group member

seconds is the mute duration in seconds. Pass 0 to unmute the member. Member-level mute state is independent from the group mute-all setting.

OpenIMClient.getInstance().groupManager.changeGroupMemberMute(new OnBase<String>() {
    @Override public void onSuccess(String data) { /* The request completed. */ }
    @Override public void onError(int code, String error) { /* code and error describe the failure. */ }
}, groupID, userID, 3600L);

A successful callback means that the setting request completed; it does not mean that every client has updated its UI. onGroupMemberInfoChanged provides the updated GroupMembersInfo. Merge it by groupID:userID. See Group overview for the complete listener setup.