function HandleAllocated: Boolean;
bool __fastcall HandleAllocated();
Indicates whether the TMetafile object has acquired a handle to the underlying GDI object.
Use HandleAllocated to determine whether the Handle property is set to an HMETAFILE value. HandleAllocated indicates whether the underlying GDI object has already been created. Use HandleAllocated rather than reading the Handle property. When an application reads the Handle property, it automatically creates a metafile and returns its handle if the underlying GDI object does not already exist.