WPFのリストビューでコードビハインドによるサンプルコード

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>net8.0-windows</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
    <UseWPF>true</UseWPF>
  </PropertyGroup>

</Project>

using System.Windows;
using System.IO;
using System.Windows.Controls;


namespace ListViewSample01;

public partial class MainWindow : Window
{
    public class FileItem
    {
        public string FilePath { get; set; } = "";
        public string FileName { get; set; } = "";
    }

    public MainWindow()
    {
        InitializeComponent();
        LoadFiles(@"C:\Windows\System32");
    }

    private void LoadFiles(string directory)
    {
        var items = new List<FileItem>();

        foreach (var path in Directory.GetFiles(directory))
        {
            items.Add(new FileItem
            {
                FilePath = path,
                FileName = Path.GetFileName(path)
            });
        }

        FileListView.ItemsSource = items;
    }
    private void FileListView_SelectionChanged(object? sender, SelectionChangedEventArgs e)
    {
        if (FileListView.SelectedItem is not FileItem item)
            return;
        
        MessageBox.Show($"Path: {item.FilePath}");
    }
}

<Window x:Class="ListViewSample01.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:ListViewSample01"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <ListView
            x:Name="FileListView"
            DisplayMemberPath="FileName"
            SelectionChanged="FileListView_SelectionChanged"
            Margin="60"/>
    </Grid>
</Window>