Gets a value that indicates whether the current type is transparent at the current trust level, and therefore cannot perform critical operations.
Assembly: mscorlib (in mscorlib.dll)
The IsSecurityCritical, IsSecuritySafeCritical, and properties report the transparency level of the type at its current trust level, as determined by the common language runtime (CLR). Using these properties is much simpler than examining the security annotations of an assembly and its types, checking the current trust level, and attempting to duplicate the runtime's rules.
For partial-trust assemblies, the value of this property depends on the current trust level of the assembly. If the assembly is loaded into a partially trusted application domain (for example, into a sandboxed application domain), then the runtime ignores the security annotations of the assembly. The assembly and all its types are treated as transparent. The runtime pays attention to the security annotations of a partial-trust assembly only when that assembly is loaded into a fully trusted application domain (for example, into the default application domain of a desktop application). By contrast, a trusted assembly (that is, a strong-named assembly that is installed in the global assembly cache) is always loaded with full trust regardless of the trust level of the application domain, so its current trust level is always fully trusted. You can determine the current trust levels of assemblies and application domains by using the Assembly.IsFullyTrusted and AppDomain.IsFullyTrusted properties.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.