IWMSBasicPlugin.OnHeartbeat (Visual Basic .NET)

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IWMSBasicPlugin.OnHeartbeat (Visual Basic .NET)

The server calls the OnHeartbeat method at every interval specified in the IWMSBasicPlugin.EnablePlugin method.




This method takes no parameters.

Return Values

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 IWMSEventLog object 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.


This method is implemented by the plug-in and called by the server. This method can be used by the plug-in to perform periodic operations. For example, this method can be used by networking plug-ins to time out connections. You can specify the heartbeat interval when you implement the IWMSBasicPlugin.EnablePlugin method. The value must be greater than 100 milliseconds or OnHeartbeat is not called. Because the heartbeat is a low-priority server event, the time at which the heartbeat is called is not guaranteed to occur at exactly the interval specified. The OnHeartbeat method is called by the server only if EnablePlugin succeeds.

Example Code

Public Overloads Sub OnHeartBeat() _
    Implements IWMSBasicPlugin.OnHeartbeat

    ' Call an internal method to keep member
    ' variables current.
End Sub


Reference: Add a reference to Microsoft.WindowsMediaServices.

Namespace: Microsoft.WindowsMediaServices.Interop.

Assembly: Microsoft.WindowsMediaServices.dll.

Library: WMSServerTypeLib.dll.

Platform: Windows Server 2003, Enterprise Edition; Windows Server 2003, Datacenter Edition; Windows Server 2008.

See Also

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