This documentation is archived and is not being maintained.

AppDomain.IsCompatibilitySwitchSet Method

Gets a nullable Boolean value that indicates whether any compatibility switches are set, and if so, whether the specified compatibility switch is set.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

public Nullable<bool> IsCompatibilitySwitchSet(
	string value


Type: System.String
The compatibility switch to test.

Return Value

Type: System.Nullable<Boolean>
A null reference (Nothing in Visual Basic) if no compatibility switches are set; otherwise, a Boolean value that indicates whether the compatibility switch that is specified by value is set.

This method tests whether the current application domain reverses breaking changes that were introduced in the .NET Framework version 4. The following table provides examples of compatibility switches that can be set to restore the behavior of earlier versions of the .NET Framework.




Code access security (CAS) for the .NET Framework 3.5 is enabled in this application domain. See <NetFx40_LegacySecurityPolicy> Element.


String sorting defaults for the .NET Framework 3.5 are enabled in this application domain. Its success requires sort00001000.dll to be installed.


TimeSpan formatting behavior for the .NET Framework 3.5 is enabled in this application domain.

.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.