Main Form

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Web.UI;
using System.Threading;
using System.Windows.Threading;
using System.ComponentModel;
using System.Net;

namespace Download_Manager
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();



        }

        DownloadFiles dlFiles = new DownloadFiles();
        BackgroundWorker bgWorker = new BackgroundWorker();
        DispatcherTimer downloadingTimer = new DispatcherTimer();

       int progressBarNumber = 0;

        //Url to be downloaded
        private void downloadLink(Uri link)
        {
            dlFiles.downloadQueue.Add(link);

        }

        private void txtDownloadLink_KeyDown(object sender, KeyEventArgs e)
        {

            //Maximum parallel downloads
            if (dlFiles.downloadQueue.Count >= 5)
            {
                MessageBox.Show("Queue is full");
                return;
            }


            var key = e.Key;

            //Enter Key
            if (key == Key.Return)
            {
                //Add download link to queue
                try
                {
                    downloadLink(new Uri(txtDownloadLink.Text));

                    //Enables progress bars based on how many files are needed to download
                    switch (progressBarNumber)
                    {
                        case 0:
                            pgBar1.Visibility = System.Windows.Visibility.Visible;
                            break;
                        case 1:
                            pgBar2.Visibility = System.Windows.Visibility.Visible;
                            break;
                        case 2:
                            pgBar3.Visibility = System.Windows.Visibility.Visible;
                            break;
                        case 3:
                            pgBar4.Visibility = System.Windows.Visibility.Visible;
                            break;
                        case 4:
                            pgBar5.Visibility = System.Windows.Visibility.Visible;
                            break;
                    }

                    progressBarNumber++;


                }
                catch (UriFormatException ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            downloadingTimer.Interval = new TimeSpan(0, 0, 0, 0, 10);
            downloadingTimer.Tick += downloadingTimer_Tick;
        }




        private void downloadingTimer_Tick(object sender, EventArgs e)
        {

            if (dlFiles.isDownloadComplete)
            {

                //Reset progress bars
                foreach (ProgressBar p in gridProgressBars.Children)
                {
                    p.Visibility = System.Windows.Visibility.Hidden;
                    p.Value = 0;
                    //p.Maximum = 0;
                }
                downloadingTimer.Stop();
                dlFiles.isDownloadComplete = true;
                progressBarNumber = 0;
                return;
            }

            int percentComplete = dlFiles.percent;
            int totalBytesToRecieve = dlFiles.totalBytesToRecieve;

            //Which progress bar to work with
            //Download queue index = 0 Progressbar = 1 etc...
            switch(dlFiles.fileToDownloadIndex)
            {
                case 0:
                    pgBar1.Value = percentComplete;
                    pgBar1.Maximum = totalBytesToRecieve;
                    break;
                case 1:
                    pgBar2.Value = percentComplete;
                    pgBar2.Maximum = totalBytesToRecieve;
                    break;
                case 2:
                    pgBar3.Value = percentComplete;
                    pgBar3.Maximum = totalBytesToRecieve;
                    break;
                case 3:
                    pgBar4.Value = percentComplete;
                    pgBar4.Maximum = totalBytesToRecieve;
                    break;
                case 4:
                    pgBar5.Value = percentComplete;
                    pgBar5.Maximum = totalBytesToRecieve;
                    break;
            }
        }

        //Begin Download
        private void btnStartDownload_Click(object sender, RoutedEventArgs e)
        {
            if(downloadingTimer.IsEnabled)
            {
                MessageBox.Show("Download has already started");
                return;
            }
            if(dlFiles.downloadQueue.Count == 0)
            {
                MessageBox.Show("Queue is empty");
                return;
            }
            dlFiles.startDownload();
            downloadingTimer.Start();
        }
    }
}