Xojo.Core.MemoryBlock.Size
From Xojo Documentation
Read-Only Property (As UInteger )
The size (in bytes) of the MemoryBlock.
Notes
If the size is unknown, this returns &hFFFFFFFF (32-bit apps) or &hFFFFFFFFFFFFFFFF (64-bit app).
The size (in bytes) of the MemoryBlock.
If the size is unknown, this returns &hFFFFFFFF (32-bit apps) or &hFFFFFFFFFFFFFFFF (64-bit app).