The TraceSwitch.OnSwitchSettingChanged method is used by the .NET framework to validate and correct the value of a switch initialized via a configuration file. A message is written to all trace listeners if the switch value specified in the configuration file is not defined by the System.Diagnostics.TraceLevel enumeration and the switch is set to a defined value.

If you attempt in your code to set the TraceSwitch.Level property to a value that is not defined by the System.Diagnostics.TraceLevel enumeration, an ArgumentException exception is thrown.

Namespace: System.Diagnostics
Assembly: System (in System.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0