This is my code of dll usage:
implementation
procedure proced_(var i:Real); stdcall; external 'libo3.dll';
...
procedure TForm1.Button1Click(Sender: TObject);
var
r:Real;
begin
r:=6;
proced_(r);
Label1.Caption:=FloatToStr(r);
end;
procedure "proced_" in dll changes the value of r, and r on label is correct, but at end of Button1Click I get AV in TControlClick - include/control.inc
I forgot something in calling to the library?