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StringToStreamANSI

procedure StringToStreamANSI(const aData : string; M : TStream);

Example​

procedure ScriptEvent(var Value: variant);
var
  Buffer: TMemoryStream;
begin
  Buffer := TMemoryStream.Create;
  try
    StringToStreamANSI('EDI-1001', Buffer);
    Value := StreamToStringANSI(Buffer);
  finally
    Buffer.Free;
  end;
end;

Usage​

StringToStreamANSI encodes a string with the system ANSI encoding into a supplied stream from position zero.

Parameters

NameTypeDescription
aDatastring, constText to encode using the process-wide ANSI encoding captured from Windows GetACP on first use.
MTStreamExisting writable, seekable caller-owned stream.

Returns

No value. Success resets position to zero; old bytes beyond the encoded length remain.

Errors

Nil-stream, seek, encoding, allocation and exact-write failures propagate without rollback.

Usage notes

Record the required code page in the integration specification. If the format simply says "text", prefer an explicit Unicode encoding such as UTF-8.

Additional Technical Info​

StringToStreamANSI converts text through the Windows/system ANSI code page and writes the resulting bytes at stream offset zero. It is for explicitly legacy code-page contracts, not for portable Unicode interchange.

The example round-trips a fictional ASCII-range identifier. It is source-reviewed and is not executed by the documentation workflow.

Implementation

The wrapper selects TEncoding.ANSI and calls shared StringToMemoryStream. The helper creates a non-owning TBinaryWriter, rewinds, allocates GetBytes(aData), writes the complete array through WriteBuffer, rewinds again and frees only the writer.

Edge cases and quirks

  • Characters not representable in the active code page can be substituted by the current Windows conversion. No round-trip or loss check is performed.
  • The output can differ across Velox hosts whose Windows system ANSI code pages differ. Changing only the service account on one configured host does not make this function choose a different code page.
  • No BOM or code-page identifier is written.
  • Existing content is not truncated. Shorter text leaves a stale tail; empty text leaves all old bytes intact.
  • Failure can leave a partially overwritten stream and a non-zero position.

Side effects

Overwrites from offset zero, can extend and repositions M; never shortens or frees it.

Performance and concurrency

Allocates the full encoded array, then copies it into the stream. Shared-stream access requires external coordination; the process-wide encoding singleton is stable after its thread-safe first creation.

Related entries

External references

Created 2026-07-15