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TStringStream

TStringStream = class(TStream)

Example​

procedure UseTextAsStream(const Text: String);
var
  Source: TStringStream;
begin
  Source := TStringStream.Create(Text);
  try
    // Source.Position = 0; Source.Size is the encoded byte count.
  finally
    Source.Free;
  end;
end;

Usage​

TStringStream converts an initial Unicode String to host-default encoded bytes while exposing only the base TStream surface to Velox scripts.

Additional Technical Info​

TStringStream makes encoded bytes derived from a String available through the TStream cursor/I/O contract. Velox exposes only Create(AString) plus inherited TStream members.

The native RAD Studio 37 class actually descends through TBytesStream and TMemoryStream, but the PascalScript compiler registers it directly under TStream. Consequently, native memory-stream-only methods such as Clear, LoadFromFile, LoadFromStream and SetSize are not callable through this scripting type even though they exist on the runtime object.

Encoding and content access​

The exposed constructor calls native TStringStream.Create(AString), which uses TEncoding.Default. The resulting bytes therefore depend on the Velox host's default code page/encoding. Size is encoded byte length, not String character count, and Position begins at zero.

This makes the class unsuitable as a portable wire-format choice when systems must agree on UTF-8, UTF-16 or another explicit encoding. Prefer the Code Library's encoding-specific StringToStream functions for deterministic integration payloads.

Native TStringStream exposes DataString and Encoding, but neither is registered in this visible scripting surface. Read bytes or use the matching stream-to-string helper instead. Inherited raw Read/Write still use the Velox String-as-byte-buffer adapter and do not automatically decode/encode each call.

Lifetime​

A constructed instance is script-owned and must be freed. It owns its encoded byte buffer. Passing it to another method normally lends the object for the duration of that call; do not free it while a consumer still uses it. It is mutable, cursor-based and not thread-safe.

The example is source-reviewed only; no string stream was created.

External references

Created 2026-07-15