x.xxxx is not a valid floating point. Converting between languages/locals

Question

I have a spanish user who is getting an invalid floating point error when doing this

var
  S : String;
  R : Real;
begin
  S := \'3.12345\';
  R         


        

Answer 1

If you know that the strings use . as the decimal separator, then you should do something like

procedure TForm1.FormCreate(Sender: TObject);
begin
  Application.UpdateFormatSettings := false;
  DecimalSeparator := '.';
end;

The line

Application.UpdateFormatSettings := false;

is very important. The default value of this property is true, and in such case, the DecimalSeparator variable may be reverted to its default value (e.g. ,) anytime, for instance when you switch user.