The native window handle this widget owns (null until created).
Read-only: a widget owns its handle for its whole lifetime and the framework
relies on that invariant (GC pinning, the HWND→widget registry). Consumers
may read it for interop with raw Win32 calls but cannot reassign it.
The native window handle this widget owns (null until created).
Read-only: a widget owns its handle for its whole lifetime and the framework relies on that invariant (GC pinning, the HWND→widget registry). Consumers may read it for interop with raw Win32 calls but cannot reassign it.