Clear all saved messages

deleteAllMsgFromLocalAndSvr() clears the current account's local messages and requests deletion of that account's server-side message history. This is a high-impact operation; explain its scope and require confirmation.

OpenIMClient.getInstance().messageManager.deleteAllMsgFromLocalAndSvr(
    new OnBase<String>() {
        @Override
        public void onSuccess(String data) {
            // Clear message lists and related UI state for the current account.
        }

        @Override
        public void onError(int code, String error) {
            // Do not clear only the UI; keep existing data and report the failure.
        }
    }
);

The success callback means the deletion request completed. It does not delete message copies retained by other users, and it does not remove friendships, groups, or conversation relationships. Query a conversation again if its messages must be shown later.