C#根据身份证号码判断出生日期和性别

/// <summary>
/// 在控件验证 textBox_IdentityCard 的 Validated事件中定义身份证号码的合法性并根据身份证号码得到生日和性别 
/// </summary>
private void textBox_IdentityCard_Validated(object sender, EventArgs e)
{
  try
  {
    //获取得到输入的身份证号码
    string identityCard = textBox_IdentityCard.Text.Trim();
    if (string.IsNullOrEmpty(identityCard))

    {

      //身份证号码不能为空，如果为空返回

      MessageBox.Show("身份证号码不能为空！");

      if (textBox_IdentityCard.CanFocus)

      {

        textBox_IdentityCard.Focus();//设置当前输入焦点为textBox_IdentityCard

      }

      return;

    }

    else

    {

      //身份证号码只能为15位或18位其它不合法

      if (identityCard.Length != 15 && identityCard.Length != 18)

      {

        MessageBox.Show("身份证号码为15位或18位，请检查！");

        if (textBox_IdentityCard.CanFocus)

        {

          textBox_IdentityCard.Focus();

        }

        return;

      }

    }
    string birthday = "";
    string sex = "";
    //处理18位的身份证号码从号码中得到生日和性别代码
    if (identityCard.Length == 18)
    {
      birthday = identityCard.Substring(6, 4) + "-" + identityCard.Substring(10, 2) + "-" + identityCard.Substring(12, 2);
      sex = identityCard.Substring(14, 3);

    }<br>

    //处理15位的身份证号码从号码中得到生日和性别代码
    if (identityCard.Length == 15)
    {
      birthday = "19" + identityCard.Substring(6, 2) + "-" + identityCard.Substring(8, 2) + "-" + identityCard.Substring(10, 2);
      sex = identityCard.Substring(12, 3);
    }<br>
    textBox_Birthday.Text = birthday;
    //性别代码为偶数是女性奇数为男性
    if (int.Parse(sex) % 2 == 0)
    {
      this.comboBox_Sex.Text = "女";
    }

    else
    {
      this.comboBox_Sex.Text = "男";
    }
  }
  catch (Exception ex)

  {

    MessageBox.Show("身份证号码输入有误");
    if (textBox_IdentityCard.CanFocus)
    {
      textBox_IdentityCard.Focus();
    }
    return;
  }
}