void with_Items_AddRange_DataSource()
        {
            string[] x = new string[4];

            x[0] = "1";
            x[1] = "2";
            x[2] = "11";
            x[3] = "22";

            //listBox1.Items.AddRange(x);// by default no item is selected
            listBox1.DataSource = x; // by default the first item is selected
        }
        void with_Items_Add()
        {
            string[] x = new string[4];

            x[0] = "1";
            x[1] = "2";
            x[2] = "11";
            x[3] = "22";

            for (int i = 0; i < x.Length; i++)
                listBox1.Items.Add(x[i]); // by default the first item is selected
        }