C#Combobox显示名称保存代码

private void Form1_Load(object sender, EventArgs e)
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("key", System.Type.GetType("System.Int32"));
            dt.Columns.Add("value",System.Type.GetType("System.String"));
            DataRow dr = dt.NewRow();
            dr[] = "";
            dr[] = "男";
            DataRow dr1 = dt.NewRow();
            dr1[] = "";
            dr1[] = "女";
            dt.Rows.Add(dr);
            dt.Rows.Add(dr1);
            comboBox1.DataSource = dt;
            comboBox1.ValueMember = "key";
            comboBox1.DisplayMember = "value";
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            string s_key = comboBox1.SelectedValue + "";
            string s_value = comboBox1.Text;
        }