解决方法
Utf8Encode函数将WideString字符串作为参数并返回Utf-8字符串.
样品：
procedure ConvertANSIFileToUTF8File(AInputFileName,AOutputFileName: TFileName);
var
Strings: TStrings;
begin
Strings := TStringList.Create;
try
Strings.LoadFromFile(AInputFileName);
Strings.Text := UTF8Encode(Strings.Text);
Strings.SaveToFile(AOutputFileName);
finally
Strings.Free;
end;
end;