CyberX8/CyberX8_MainPages/Unity/TextBoxMaxValue.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;

namespace CyberX8_MainPages.Unity
{
    public class TextBoxMaxValue
    {
        public static int GetMaxValue(DependencyObject obj)
        {
            return (int)obj.GetValue(MaxValueProperty);
        }

        public static void SetMaxValue(DependencyObject obj, int value)
        {
            obj.SetValue(MaxValueProperty, value);
        }

        public static readonly DependencyProperty MaxValueProperty =
            DependencyProperty.RegisterAttached("MaxValue", typeof(int), typeof(TextBoxMaxValue), new PropertyMetadata(OnTextBoxPropertyChanged));

        private static void OnTextBoxPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            TextBox tb = d as TextBox;
            if (tb == null)
            {
                return;
            }
            tb.Tag = e.NewValue;
            tb.TextChanged += Tb_TextChanged;
        }

        private static void Tb_TextChanged(object sender, TextChangedEventArgs e)
        {
            TextBox tb = sender as TextBox;

            if (tb.Text == "")
            {
                return;
            }
            string str = tb.Text; 
            str = Regex.Replace(str, @"[^\d.\d]", "");

            if (Regex.IsMatch(str, @"^[+-]?\d*[.]?\d*$"))
            {
                decimal result;
                 decimal.TryParse(str,out result);
                if (result > (int)tb.Tag)
                {
                    tb.Text = tb.Tag.ToString();
                }
            }
        }
    }
}