Trouble specifying destination filename for use in FileInfo.Copy example from MSDN

Question

I'm using two DateTimePickers to specify a date range, then I'm using a CheckedListBox to specify some strings for filenames with wildcards to enumerate in each day's subdirectory contained within a system environment variable path. I want to copy from that source to a destination using FileInfo.Copy.

I have my code already creating the necessary directories. But I'm having trouble specifying the destination filenames -- they are not being specified at all with how I have this written.

I was thinking of using regular expressions, but after some digging I found this MSDN article that seems to do what I want already. I think I need to alter my code in order to use it. I could use some assistance fitting what I already have into what MSDN shows in its example.

I have been on this part of my program for a month now, which has led me to learn quite a bit about c#, parallel programming, async, lambda expressions, background workers, etc. What seems should be simple has become a big rabbit hole for me. For this question I just need a nudge in the right direction, and I will greatly appreciate it!

Here is my code as it stands:

    private async void ProcessFiles()
    {

        // create a list of topics
        var topics = topicsBox.CheckedItems.Cast<string>().ToList();

        // create a list of source directories based on date range
        var directories = new List<string>();
        var folders = new List<string>();
        for (DateTime date = dateTimePicker1.Value.Date;
            date.Date <= dateTimePicker2.Value.Date;
            date = date.AddDays(1))
        {
            directories.Add(_tracePath + @"\" + date.ToString("yyyy-MM-dd") + @"\");
            folders.Add(@"\" + date.ToString("yyyy-MM-dd") + @"\");
        }

        // create a list of source files to copy and destination
        // revise based on https://msdn.microsoft.com/en-us/library/kztecsys.aspx?f=255&MSPPError=-2147217396
        foreach (var path in directories)
        {
            var path1 = path;
            try
            {
                foreach (var files2 in folders)
                {
                    // create the target directory
                    var destPath = textBox1.Text + @"\" + textBox4.Text + files2;
                    Console.WriteLine("Target directory is {0}", destPath);
                    Console.WriteLine("Destination filename is {0}", files2);
                    foreach (var files in topics)
                    {
                        foreach (string sourcePath in Directory.EnumerateFiles(path1, files + "*.*", SearchOption.AllDirectories))
                        {
                            // copy the files to the temp folder asynchronously
                            Console.WriteLine("Copy {0} to {1}", sourcePath, destPath);
                            Directory.CreateDirectory(sourcePath.Replace(sourcePath, destPath));
                        }
                    }
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
        }
    }

Answer 1

So sourcePath contains the source path and filename. You can easily construct the destination path from that, like so:

// Get just the filename of the source file.
var filename = Path.GetFileName(sourcePath);

// Construct a full path to the destination by combining the destination path and the filename.
var fullDestPath = Path.Combine(destPath, filename);

// Ensure the destination directories exist. Don't pass in the filename to CreateDirectory!
Directory.CreateDirectory(destPath);

Then you can copy the file (synchronously) like this:

File.Copy(sourcePath, fullDestPath);