I would like to show you recursively reading files in folder and subfolders in C#.

Since i build this project for web, so please feel free to change for windows or console App. 

 protected void Page_Load(object sender, EventArgs e)
    {
        StringBuilder sb = new StringBuilder();
        ReadFolder(new DirectoryInfo(@"C:\Your Path"), ref sb);
        pnlResult.Controls.Add(new LiteralControl(sb.ToString()));
    }

    private void ReadFolder(DirectoryInfo directoryInfo, ref StringBuilder sb)
    {
        // Reads files 

foreach (FileInfo file in directoryInfo.GetFiles())
        {
            sb.AppendFormat("File:{0}<br>",file.FullName);   
        }

        // Reads Folders
        foreach (DirectoryInfo subfolder in directoryInfo.GetDirectories())
        {
            sb.AppendFormat("Folder:{0}<br>",subfolder.FullName); 
            ReadFolder(subfolder, ref sb);
        }
    }