Called periodically when the password is about to expire or has expired. It will typically be called at these times: on device boot, once per day before the password expires, and at the time when the password expires.

If the password is not updated by the user, this method will continue to be called once per day until the password is changed or the device admin disables password expiration.

The admin will typically post a notification requesting the user to change their password in response to this call. The actual password expiration time can be obtained by calling DevicePolicyManager.GetPasswordExpiration(Android.Content.ComponentName)

The admin should be sure to take down any notifications it posted in response to this call when it receives DeviceAdminReceiver.OnPasswordChanged(Android.Content.Context, Android.Content.Intent).

[Android Documentation]