Drag and Drop 1 (Windows Forms)

Form1.cs

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

// Label:
//  Allow Drop = true
//  DragEnter
//  DragDrop

// Listbox:
//  HorizontalScrolbar = true
//  ScrollAlwaysVisible = true

namespace DragAndDrop1
{
    public partial class Form1 : Form
    {
        public const string DIR = "C:\\test";

        public Form1()
        {
            InitializeComponent();
        }

        private void label1_DragEnter(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(DataFormats.FileDrop))
                e.Effect = DragDropEffects.Copy;
        }

        private bool dispFile(string file)
        {
            try
            {
                richTextBox1.Text = File.ReadAllText(file);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return false;
            }

            return true;
        }

        private bool copyFile(string source, string dest)
        {
            try
            {
                if (File.Exists(dest))
                    File.Delete(dest);

                File.Copy(source, dest);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return false;
            }

            return true;
        }

        private bool createDir(string dir)
        {
            try
            {
                if (!Directory.Exists(DIR))
                    Directory.CreateDirectory(DIR);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return false;
            }

            return true;
        }

        private void label1_DragDrop(object sender, DragEventArgs e)
        {
            string[] fileNames = (string[]) e.Data.GetData(DataFormats.FileDrop, false);

            if (e.Data.GetDataPresent(DataFormats.FileDrop))
            {
                if (fileNames.Count() > 1)
                {
                    MessageBox.Show("Nur eine Datei");
                }
                else
                {
                    string file = fileNames[0];
                    string[] fields = file.Split('\\');

                    if (!createDir(DIR))
                    {
                        MessageBox.Show($"Error:Could not create dir: {DIR}");
                        return;
                    }

                    string path = $"{DIR}\\{fields[fields.Count() - 1]}";

                    label1.Text = file;

                    if (!dispFile(file))
                    {
                        MessageBox.Show($"Error:Could not display file: {file}");
                        return;
                    }

                    if (!copyFile(file, path))
                    {
                        MessageBox.Show($"Error:Could not copy file: {file} -> {path}");
                        return;
                    }
                }
            }
        }
    }
}