1# MediaKeySession_Callback 2 3## Overview 4 5The struct describes the callback used to listen for events such as media key expiry or change, without returning media key session instances. It applies to the scenario where a single media key session needs to be decrypted. 6 7**Since**: 11 8 9**Related module**: [Drm](capi-drm.md) 10 11**Header file**: [native_mediakeysession.h](capi-native-mediakeysession-h.md) 12 13## Summary 14 15### Member Variables 16 17| Name| Description| 18| -- | -- | 19| [MediaKeySession_EventCallback](capi-native-mediakeysession-h.md#mediakeysession_eventcallback) eventCallback | Event callback, for example, a media key expiry event.| 20| [MediaKeySession_KeyChangeCallback](capi-native-mediakeysession-h.md#mediakeysession_keychangecallback) keyChangeCallback | Callback of the media key change event.| 21