Btukfyl

I've been trying to find a solution for this, but at this point nothing that I've found has made the click. I'm starting with WPF, so I may just missed some obvious answer, but I would highly appreciate an answer for dumbs. This is the situation:

My app is structured using MVVM. Its main functionality is called from a button. Once called, it will loop through all the files within an specified directory and perform some renaming. While doing this loop, I wanted to show a progress bar indicated how many files have been renamed out of the total.
The progress value is a property binded to the Progressbar control

I've only been able to update the progress bar asynchronously; otherwise it will remain empty until the process finishes. Right now its working with a BackgroundWorker.

_bgWorker.DoWork += (s, e) =>

{

    RenamingMethod();

};

...

RenamingMethodCommand = new RelayCommand(_ =>_bgWorker.RunWorkerAsync());

For performing the renaming, a hash is expected in the name of the file. This hash will be translated to a user-entered value if found, otherwise a window should be displayed asking the user to enter it.

This window is not being able to be displayed in a MTAThread (I'm using ShowDialog, I haven't found any other way to make it appear), and so I can't call it from the async methods in my main window. The only way I found to make it work was calling everything inside RenamingMethod like this:

public void RenamingMethod()

{

    Application.Current.Dispatcher.Invoke((Action)delegate

    {

        //code for renaming

    }

}

At this point, the progress bar is only updated the moment I close the pop up window. Then it remains on the same value until a new window is opened and closed.

I would like to open the pop up window from the asynchronous method that updates the progress bar, so the evolution of this is smooth, and its stopped when a new window is openned. Or being able to update the progress bar synchronously would probably work as well.

Here's the code in more detail:

public void RenameMethod()

{

    Application.Current.Dispatcher.Invoke((Action)delegate

    {

        IEnumerable<string> files = Directory.EnumerateFiles(

            OriginMediaFolder, 

            "*.*",

            SearchOption.AllDirectories).

        Where(name => name.EndsWith(".jpg") || name.EndsWith(".mp4"));



        int numberOfFiles = files.Count();

        float fileNumber = 0;

        foreach (string file in files)

        {

            MoveAndRenameFile(file);

            ProgressValue = (int)(100 * (fileNumber++ / numberOfFiles));

        }

    });

}



public void MoveAndRenameFile(string file)

{

    //Name structure: path/1234567891234567-hash.ext

    string fileName = Regex.Match(file, @"[^/\]+.",RegexOptions.RightToLeft).

        Value.TrimEnd('.');

    string date = fileName.Substring(0, 16);

    string hash = fileName.Substring(17);

    if (!HashToName(hash, out string gameName))

    {

        var gameNamingWindow = GetNewNameFromUser(hash);

    }

    string extension = Regex.Match(file, @"..+Z", RegexOptions.RightToLeft).Value;



    if (!Directory.Exists(DestinationMediaFolder + "/" + gameName))

        Directory.CreateDirectory(DestinationMediaFolder + "/" + gameName);



    File.Move(file, DestinationMediaFolder + "/" + gameName + "/" + date + extension);

}



public string GetNewNameFromUser(string hash)

{

    var gameNamingWindow = new NewGameWindow.MainWindow(OriginMediaFolder, hash);

    if (gameNamingWindow.ShowDialog().Value)

    {

        string gameName = gameNamingWindow.Result;

        NameHashes.Add(new NameHash

        {

            GameName = gameName,

            Hash = hash

        });

        return gameName;

    }

    return hash;

}

The Invoke call switches over to the GUI thread, so you're basically tying up that thread doing all your work and effectively negating the whole point of using a worker thread to begin with. Change RenameMethod() so that that only thing inside the Invoke block is the one thing that actually needs to be there i.e. the line that updates the progress bar.

Better yet, start using proper data binding for your GUI controls so that you don't have to mess around with task switching at all.