public void Execute(params string[] parameters) { int size, index; try { if (!Int32.TryParse(parameters[0], out index)) { Console.WriteLine("Please check the correctness of the index!"); return; } if (!Int32.TryParse(parameters[1], out size)) { Console.WriteLine("Please check the correctness of the size!"); return; } picture.Width(index, size); } catch (Exception e) { Console.WriteLine("{0} Exception caught.", e); } }