WPF文本框只允许输入数字和小数

/// <summary>
        /// 限制文本框只允许输入小数
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void WaterTextBoxControl_PreviewKeyDown(object sender, KeyEventArgs e)
        {
            var textBox = sender as TextBox;

            if ((e.Key == Key.OemPeriod && textBox.Text.Contains(".")) || e.Key == Key.OemPeriod && string.IsNullOrWhiteSpace(textBox.Text))
            {
                e.Handled = true;
                return;
            };

            if (!((e.Key >= Key.D0 && e.Key <= Key.D9)
                || e.Key == Key.Delete || e.Key == Key.Back || e.Key == Key.OemPeriod
                || e.Key == Key.Tab || e.Key == Key.OemBackTab
                || e.Key == Key.Left || e.Key == Key.Right || e.Key == Key.Up || e.Key == Key.Down)
                || (e.KeyboardDevice.Modifiers == ModifierKeys.Control && e.Key == Key.A))
            {
                if (e.KeyboardDevice.Modifiers != ModifierKeys.Control)
                {
                    e.Handled = true;
                }
            }
        }

设置文本框的InputMethod.IsInputMethodEnabled="False" 文本框只允许英文模式