[C#] TextBox에 입력받은 문자열이 숫자 인지 판별

private void okbt_Click(object sender, EventArgs e)
        {
            MealShowProc();
            if (TextBoxNullCheck())
            {
                if (Char.IsDigit(Hourtb.Text, 0) && Char.IsDigit(mintb.Text, 0))//TextBox가 숫자인지 검사
                {
                    SettingTimer();
                    TimesettingHide();
                    SoundButtonShow();
                }
                else
                {
                    MessageBox.Show("Only Interger Press");
                    return;
                }
            }
            else
            {
                MessageBox.Show("Input Check");
            }
           
        }