The GetExpirationTime method retrieves the content expiration date.
void IWMSDataContainerVersion.GetExpirationTime( ref DateTime pdateExpirationTime );
Reference to a DateTime containing the expiration date.
This method does not return a value. To report an error, the plug-in can throw a COMException object to the server. If the plug-in uses the IWMSEventLogIWMSEventLog Object (C#) to log error information, it is recommended that it throw NS_E_PLUGIN_ERROR_REPORTED (0xC00D157D). Typically, the server attempts to make plug-in error information available to the server object model, the Windows Event Viewer, and the troubleshooting list in the details pane of the Windows Media Services MMC. However, if the plug-in uses the IWMSEventLog object to send custom error information to the Windows Event Viewer, throwing NS_E_PLUGIN_ERROR_REPORTED stops the server from also logging to the event viewer. For more information about plug-in error information, see Identifying Plug-in Errors.
When content is downloaded, an expiration date must be associated with it. The date is specified by the origin sever to indicate the time at which content can no longer be considered current. A cache proxy plug-in must check the date to determine whether the content has expired. If it has, the plug-in must call IWMSCacheProxyServerCallback.OnCompareContentInformation so that the cache server can retrieve content information from the origin server and compare it to information about the cached content. If it has not expired, the plug-in can direct the server to stream the content to a client.
Reference: Add a reference to Microsoft.WindowsMediaServices.
Platform: Windows Server 2003, Enterprise Edition; Windows Server 2003, Datacenter Edition; Windows Server 2008.