Component-oriented-programming/ComponentLibrary1/limited_text/LimitedText.cs

using ComponentLibrary1.limited_text;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace ComponentLibrary1
{
	public partial class LimitedText : UserControl
	{
		private event EventHandler? _changeEvent;
		public event EventHandler ChangeEvent
		{
			add
			{
				_changeEvent += value;
			}
			remove
			{
				_changeEvent -= value;
			}
		}

		private int? _min = null;
		public int? Min
		{
			get
			{
				return _min;
			}
			set
			{
				if (value < 0)
				{
					return;
				}
				if (Max != null && value > Max)
				{
					return;
				}
				_min = value;
			}
		}
		private int? _max = null;
		public int? Max
		{
			get
			{
				return _max;
			}
			set
			{
				if (value < 0)
				{
					return;
				}
				if (Max != null && value < Min)
				{
					return;
				}
				_max = value;
			}
		}

		public string TextField
		{
			get
			{
				if (Min == null || Max == null)
				{
					throw new RangeUndefinedException();
				}
				if (textBox.Text.Length < Min || textBox.Text.Length > Max)
				{
					throw new OutOfRangeException((int)Min, (int)Max);
				}
				return textBox.Text;
			}
			set
			{
				if (Min == null || Max == null)
				{
					return;
				}
				if (value.Length >= Min && value.Length <= Max)
				{
					return;
				}
			}
		}

		public LimitedText()
		{
			InitializeComponent();
		}

		private void textBox_TextChanged(object sender, EventArgs e)
		{
			_changeEvent?.Invoke(this, e);
		}
	}
}