PIbd-32_BuslaevRoman_KOP/WinFormsControlLibrary1/TemplatedListBox.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Globalization;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Xml.Linq;
using WinFormsControlLibrary1.Exceptions;

namespace WinFormsControlLibrary1;

public partial class TemplatedListBox : UserControl
{
    private readonly ListBox _lb = new() { Dock = DockStyle.Fill };

    private string _template = "";
    private string _open = "{";
    private string _close = "}";

    public event EventHandler? SelectedIndexChanged;

    public TemplatedListBox()
    {
        InitializeComponent();
        Controls.Add(_lb);
        _lb.HorizontalScrollbar = true;
        _lb.SelectedIndexChanged += (_, __) => SelectedIndexChanged?.Invoke(this, EventArgs.Empty);
    }

    public void SetTemplate(string template, string open = "{", string close = "}")
    {
        if (string.IsNullOrWhiteSpace(template))
            throw new TemplateConfigurationException("Шаблон не должен быть пустым.");

        _template = template;
        _open = open;
        _close = close;

        if (template[0] == open[0] || template[template.Length - 1] == close[0])
            throw new TemplateConfigurationException("Шаблон не должен начинаться или заканчиваться свойством.");

        CheckNoDoubleProperties(template, open, close);

    }

    public void Clear()
    {
        _lb.Items.Clear();
    }

    public void AddItem<T>(T item)
    {
        if (string.IsNullOrEmpty(_template))
            throw new TemplateConfigurationException("Сначала вызовите SetTemplate.");

        var text = Render(item);
        _lb.Items.Add(text);
    }

    private string Render(object obj)
    {
        if (string.IsNullOrEmpty(_template)) return string.Empty;

        string result = _template;
        var type = obj.GetType();

        foreach (var p in type.GetProperties())
        {
            if (!p.CanRead) continue;

            string name = p.Name;

            string val = Convert.ToString(p.GetValue(obj)) ?? string.Empty;

            result = result.Replace($"{_open}{name}{_close}", val);
        }

        foreach (var f in type.GetFields())
        {
            string name = f.Name;

            string val = Convert.ToString(f.GetValue(obj)) ?? string.Empty;

            result = result.Replace($"{_open}{name}{_close}", val);
        }

        return result;
    }

    public T? GetSelectedObject<T>() where T : class, new()
    {
        if (_lb.SelectedIndex == -1)
        {
            return null;
        }
        string row = _lb.SelectedItem!.ToString()!;
        T obj = new T();
        var type = typeof(T);

        List<string> substrings = new List<string>();
        List<string> props = ExtractPlaceholders(_template, _open, _close);

        string template = _template;

        substrings.AddRange(template.Split(_open + _close));

        int int1 = 0; int int2 = 0;

        for (int i = 0; i < props.Count; i++)
        {
            int1 = row.IndexOf(substrings[i]) + substrings[i].Length;
            int2 = row.IndexOf(substrings[i + 1]);
            if (substrings[i + 1] == "")
            {
                int2 = row.Length;
            }
            var value = row[int1..int2];

            var p = type.GetProperty(props[i]);

            if (p is null) continue;

            p.SetValue(obj, Convert.ChangeType(value, p.PropertyType));
        }

        return obj;
    }

    private List<string> ExtractPlaceholders(string template, string open, string close)
    {
        var names = new List<string>();
        int i = 0;
        while (i < template.Length)
        {
            if (template[i] == open[0])
            {
                int j = template.IndexOf(close, i + 1, StringComparison.Ordinal);
                string name = template.Substring(i + 1, j - i - 1).Trim();
                names.Add(name);
                i = j + 1;
            }
            else i++;
        }
        return names;
    }

    private static void CheckNoDoubleProperties(string template, string open, string close)
    {
        for (int i = 0; i < template.Length; i++)
        {
            if (template[i] == close[0])
            {
                int k = i + 1;
                while (k < template.Length && char.IsWhiteSpace(template[k])) k++;
                if (k < template.Length && template[k] == open[0])
                    throw new TemplateConfigurationException("В шаблоне не должно идти два свойства подряд без текста между ними.");
            }
        }
    }

}