自定义数字控件方法

 private void NoTextBox_KeyPress(object sender, KeyPressEventArgs e)
        {
            char kc = e.KeyChar;
            if ((kc < 48 || kc > 57) && kc != 8 && kc != 46)
            {
                e.Handled = true;
            }
            if (kc == 8)
            {
                e.Handled = false;
            }
            else
            {
                e.Handled = !IsNumeric(this.NoTextBox, e.KeyChar.ToString());
            }
        }

        /// <summary>
        /// 数値パターン
        /// </summary>
        private readonly Regex numericPattern = new Regex("^([0-9])*$");

        /// <summary>
        /// 数値（整数型）
        /// </summary>
        private readonly Regex integerPattern = new Regex(@"^\d+$");

        /// <summary>
        /// 数値（小数型）
        /// </summary>
        private readonly Regex floatPattern = new Regex(@"^[+-]?\d*[.]?\d*$");

        /// <summary>
        /// 数値（符号なし小数型）
        /// </summary>
        private readonly Regex unsignedFloatPattern = new Regex(@"^\d*[.]?\d*$");

        /// <summary>
        /// 数値の型
        /// </summary>
        public enum NumericMode
        {
            /// <summary>
            /// 数値
            /// </summary>
            Numeric = 0,

            /// <summary>
            /// 整数型
            /// </summary>
            Integer = 1,

            /// <summary>
            /// 小数型
            /// </summary>
            Float = 2,

            /// <summary>
            /// 符号なし小数型
            /// </summary>
            UnsignedFloat = 3
        }

        private bool IsNumeric(TextBox txtBox, string value, NumericMode NumericType = NumericMode.Numeric, int DecimalPlaces = 0)
        {
            if (value.Length == 0)
            {
                return true;
            }

            bool result = true;
            switch (NumericType)
            {
                case NumericMode.Numeric:
                    result = numericPattern.IsMatch(value);
                    break;
                case NumericMode.Integer:
                    result = integerPattern.IsMatch(value);
                    if (result)
                    {
                        if ("0".Equals(txtBox.Text))
                        {
                            txtBox.Text = string.Empty;
                        }
                    }

                    break;
                case NumericMode.Float:
                    result = floatPattern.IsMatch(value);
                    if (result && DecimalPlaces == 0 && ".".Equals(value))
                    {
                        result = false;
                    }
                    if (result && txtBox.Text.Contains("."))
                    {
                        string[] arrInputValue = txtBox.Text.Split('.');
                        if (arrInputValue.Length == 2
                            && arrInputValue[1].Length >= DecimalPlaces)
                        {
                            result = false;
                        }
                    }
                    if (result)
                    {
                        if ("0".Equals(txtBox.Text) && !".".Equals(value))
                        {
                            txtBox.Text = string.Empty;
                        }
                    }

                    break;
                case NumericMode.UnsignedFloat:
                    result = unsignedFloatPattern.IsMatch(value);
                    if (result && DecimalPlaces == 0 && ".".Equals(value))
                    {
                        result = false;
                    }
                    if (result && txtBox.Text.Contains("."))
                    {
                        string[] arrInputValue = txtBox.Text.Split('.');
                        if (arrInputValue.Length == 2
                            && arrInputValue[1].Length >= DecimalPlaces)
                        {
                            result = false;
                        }
                    }
                    if (result)
                    {
                        if ("0".Equals(txtBox.Text) && !".".Equals(value))
                        {
                            txtBox.Text = string.Empty;
                        }
                    }

                    break;
            }
            return result;
        }