C# scan a folder and open files that have been created after a certain time

Question

I am writing a little program in C# that scans a folder and opens the files that have been created after 5.30pm after a button has been pressed on the program. This will also have to search within sub-folders.

I need a couple of solutions to point me in the correct direction as I'm not sure how I would do this.

This is part of a folder watcher program. The problem is when the user goes home the PC is switched off and there are files being created to the directory after 17.30. So I need a way for when the program is restarted in the morning it detects anything created after 17.30 and open them.

    private void button1_Click(object sender, EventArgs e)
    {
        folderBrowser.ShowDialog();

        textBox1.Text = folderBrowser.SelectedPath;
        filewatcher.Path = textBox1.Text;
        Registry.SetValue("HKEY_CURRENT_USER\\SOFTWARE\\COMPANY\\FOLDERWATCHER", "FOLDERPATH", textBox1.Text);
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        String WatchFolder = Registry.GetValue("HKEY_CURRENT_USER\\SOFTWARE\\COMPANY\\FOLDERWATCHER", "FOLDERPATH", "").ToString();

        textBox1.Text = WatchFolder;
        filewatcher.Path = WatchFolder;
    }

    private void Form1_Resize(object sender, EventArgs e)
    {
        if (WindowState == FormWindowState.Minimized)
        {
            ShowInTaskbar = true;
            Hide();
        }
    }

    private void fileSystemWatcher1_Changed(object sender, System.IO.FileSystemEventArgs e)
    {
        if(!e.FullPath.EndsWith("temp.temp"))
        {
            MessageBox.Show("You have a Collection Form: " + e.Name);
            Process.Start("explorer.exe", e.FullPath);
        }
    }

    private void notifyIcon1_MouseDoubleClick(object sender, MouseEventArgs e)
    {
        Show();
    }
}

This is my complete code above. I would like to use a button to open or show the files created after 17.30.

Answer 1

Look at the System.IO namespace, it has everything you need.

the DirectoryInfo and File classes will do what you want.

Answer 2

Here is the recursive method you are looking for:

public static List<string> GetFilesCreatedAfter(string directoryName, DateTime dt)
{
    var directory = new DirectoryInfo(directoryName);
    if (!directory.Exists)
        throw new InvalidOperationException("Directory does not exist : " + directoryName);
    var files = new List<string>();
    files.AddRange(directory.GetFiles().Where(n => n.CreationTime > dt).Select(n=>n.FullName));
    foreach (var subDirectory in Directory.GetDirectories(directoryName))
    {
        files.AddRange(GetFilesCreatedAfter(subDirectory,dt));
    }
    return files;
}

Hope I helped.