AnsiString To Stream

Question

I created the following code:

Function AnsiStringToStream(Const AString: AnsiString): TStream;
Begin
  Result := TStringStream.Create(AString, TEncoding.ANSI);
End;

But I'm "W1057 Implicit string cast from 'AnsiString' to 'string'"

There is something wrong with him?

Thank you.

Answer 1

In D2009+, TStringStream expects a UnicodeString, not an AnsiString. If you just want to write the contents of the AnsiString as-is without having to convert the data to Unicode and then back to Ansi, use TMemoryStream instead:

function AnsiStringToStream(const AString: AnsiString): TStream; 
begin 
  Result := TMemoryStream.Create;
  Result.Write(PAnsiChar(AString)^, Length(AString));
  Result.Position := 0; 
end; 

Since AnsiString is codepage-aware in D2009+, ANY string that is passed to your function will be forced to the OS default Ansi encoding. If you want to be able to pass any 8-bit string type, such as UTF8String, without converting the data at all, use RawByteString instead of AnsiString:

function AnsiStringToStream(const AString: RawByteString): TStream; 
begin 
  Result := TMemoryStream.Create;
  Result.Write(PAnsiChar(AString)^, Length(AString));
  Result.Position := 0; 
end;