Delphi 以WideString來做字集轉換

function WideStringToStr(CodePage: UINT; WStr: WideString): string;
var
  Len: Integer;
begin
  Len := WideCharToMultiByte(CodePage, 0, PWChar(WStr), -1, nil, 0, nil, nil);
  SetLength(Result, Len);
  WideCharToMultiByte(CodePage, 0, PWChar(WStr), Len, PChar(Result), Len, nil, nil);
end;

function StrToWideString(CodePage: UINT; Str: string): WideString;
begin
  SetLength(Result, Length(Str));
  MultiByteToWideChar(CodePage, MB_COMPOSITE, PChar(Str), -1, PWChar(Result), Length(Str));
end;