The SafeHandle.IsClosed method returns a value indicating whether the System.Runtime.InteropServices.SafeHandle object's handle is no longer associated with a native resource. This differs from the definition of the SafeHandle.IsInvalid property, which computes whether a given handle is always considered invalid. The SafeHandle.IsClosed method returns a true value in the following cases:

• The SafeHandle.SetHandleAsInvalid method was called.

• The SafeHandle.Dispose method or SafeHandle.Close method was called and there are no references to the System.Runtime.InteropServices.SafeHandle object on other threads.