UTF8 version of WIDESTRING

Question

I have a text that I need to store it in a widestring variable. But my text is UTF8 and widestring doesn't support UTF8 and converts it to some chinese characters.

so is there any UTF8 version of WIDESTRING?

I always use UTF8string but in this case I have to use WideString

Answer 1

When you assign a UTF8String variable to a WideString variable, the compiler automatically inserts instructions to decode the string (in Delphi 2009 and later). It coverts UTF-8 to UTF-16, which is what WideString holds. If your WideString variable holds Chinese characters, then that's because your UTF-8-encoded string holds UTF-8-encoded Chinese characters.

If you want your string ws to hold 16-bit versions of the bytes in your UTF8String s , then you can by-pass the automatic conversion with some type-casting:

var
  ws: WideString;
  i: Integer;
  c: AnsiChar;

SetLength(ws, Length(s));
for i := 1 to Length(s) do begin
  c := s[i];
  ws[i] := WideChar(Ord(c));
end;

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If you're using Delphi 2009 or later (which includes the XE series), then you should consider using UnicodeString instead of WideString . The former is a native Delphi type, whereas the latter is more of a wrapper for the Windows BSTR type. Both types exhibit the automatic conversion behavior when assigning to and from AnsiString derivatives like UTF8String , though, so they type you use doesn't affect this answer.

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In earlier Delphi versions, the compiler would attempt to decode the string using the system code page (which is never UTF-8). To make it decode the string properly, call Utf8Decode :

ws := Utf8Decode(s);