| handle | 安全句柄。 |
Check that the handle has been initialized, and if so, check that it is still valid.
This is almost identical to AtomicSafetyHandle.IsValidNonDefaultHandle, except that if the handle has been initialized but is no longer valid, then an ObjectDisposedException will be thrown instead of returning false.
If the handle has not been initialized, then this method will do nothing. Use AtomicSafetyHandle.IsDefaultValue to check whether a handle is still uninitialized or not.