FileInfo De,o

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


namespace Demo20180906
{
    class Program
    {
        [STAThread]
        static void Main(string[] args)
        {
            System.Windows.Forms.OpenFileDialog openDlg =
                new System.Windows.Forms.OpenFileDialog();
            if (openDlg.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                Console.WriteLine(openDlg.FileName);
                var fi = new FileInfo(openDlg.FileName);
                Console.WriteLine(fi.Length);

                Console.WriteLine(Path.GetFileNameWithoutExtension(openDlg.FileName));
            }

        }
    }
}