When overridden in a derived class, gets a value indicating whether the handle value is invalid.
Assembly: mscorlib (in mscorlib.dll)
Derived classes must implement the property so that the common language runtime can determine whether critical finalization is required. Derived classes must provide an implementation that suits the general type of handle they support (0 or -1 is invalid). These classes can then be further derived for specific safe handle types.
Unlike the IsClosed property, which reports whether the SafeHandle object has finished using the underlying handle, the property calculates whether the given handle value is always considered invalid. Therefore, the property always returns the same value for any one handle value.
.NET FrameworkSupported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0
.NET Framework Client ProfileSupported in: 4, 3.5 SP1
Portable Class LibrarySupported in: Portable Class Library
.NET for Windows Store appsSupported in: Windows 8
.NET for Windows Phone appsSupported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1
Windows Phone 8.1, Windows Phone 8, 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.