Skip to main content

LoadFromStream

procedure LoadFromStream(Stream: TStream);

Example​

procedure ReadRemainingLines(const Source: TStream; const Items: TStringList);
begin
  Source.Position := 0;
  Items.LoadFromStream(Source);
end;

Usage​

LoadFromStream replaces the list with decoded lines read from the source stream's current position through its reported size.

  • Set Position explicitly and use a stable, seekable stream whose Size is accurate.
  • Do not pass nil, a stream positioned beyond its size, or a source changing concurrently.
  • Loading is not transactional and can leave partial/new content after exceptions.

Additional Technical Info​

LoadFromStream is declared by hidden ancestor TStrings and is normally used through a concrete visible descendant such as TStringList. The caller owns the source stream and controls its starting position.

Source-backed behaviour​

The installed overload calculates Size := Stream.Size - Stream.Position, batches updates and detects a BOM or falls back to DefaultEncoding. For native line breaks and remaining size at least $15000000 (336 MiB), it uses TStreamReader with automatic BOM detection and adds lines incrementally. Otherwise it allocates a byte array for the reported remaining size, performs one Read, detects encoding and replaces text.

The ordinary branch ignores the actual byte count returned by Read; a short-reading, concurrently changing or nonstandard stream can leave zero-filled/unread tail bytes in the decode buffer. Existing entries are cleared by the text replacement. The source is not freed.

LoadFromFile supplies a shared-read file stream. Text describes line splitting. SaveToStream writes at a destination's current position.

Official RTL references​

Created 2026-07-15