Gets the category number of the event log entry.
Assembly: System (in System.dll)
Each application (event source) can define its own numbered categories and the text strings to which they are mapped. The Event Viewer can use the category to filter events in the log. The categories must be numbered consecutively beginning with the number 1. The category number is specified by the EventInstance.CategoryId property. The Event Viewer can display the category as a numeric value, or it can use the category as a resource identifier to display a localized category string. For more information, see EventInstance.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.