PIbd-32_Ismailov_R.I._COP_19/WinForms/VisualComponentsLib/MyEmailTextBox.cs

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

namespace VisualComponentsLib
{
    //Поле для ввода адреса электронной почты (адрес электронной почты должен соответствовать шаблону)
    public partial class MyEmailTextBox : UserControl
    {
        //Шаблон для textbox
        private string pattern;
        
        private string example = "example@gmail.com";
        public MyEmailTextBox()
        {
            InitializeComponent();
        }
        public string Pattern
        {
            get { return pattern; }
            set { pattern = value; }
        }
        public string TextBoxValue
        {
            get
            {
                Regex rg = new Regex(Pattern);
                bool address = rg.IsMatch(emailTextBox.Text);
                if (address)
                {
                    return emailTextBox.Text;
                }
                else
                {
                    Error = "Некорректный ввод";
                    return null;
                }
            }
            set
            {
                Regex rg = new Regex(Pattern);
                bool address = rg.IsMatch(value);
                if (address)
                {
                    emailTextBox.Text = value;
                }
                else
                {
                    Error = "Некорректный ввод";
                }
            }
        }
        public string Error
        {
            get; private set;
        }
        public void setExample(string str)
        {
            Regex rg = new Regex(Pattern);
            bool address = rg.IsMatch(str);
            if (address)
            {
                example = str;
            }

        }
        private void textBox_Enter(object sender, EventArgs e)
        {
            int VisibleTime = 2000;  
            ToolTip tooltip = new ToolTip();
            tooltip.Show(example, emailTextBox, 30, -20, VisibleTime);
        }

        private EventHandler onValueChanged;
        public event EventHandler ValueChanged
        {
            add
            {
                onValueChanged += value;
            }
            remove
            {
                onValueChanged -= value;
            }
        }

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