從給定字符串中截取n個字節的字符（解決漢字截取亂碼問題）

function GetNBytesChar(s: Ansistring; n: Integer): string;
var
  aStr: AnsiString;
  bStr: WideString;
begin
  aStr := Copy(s, 1, n);
  bStr := aStr;
  if aStr = bStr then
    Result := astr
  else
    Result := Copy(s, 1, n-1);
end;