Actually, i want to put this in Windows Phone.
Since, i have a link (http://xxxx.com/xxxx/abc.pdf) and, i want to download in my Isolated Storage.
 
// My Code
  private void cancleButton_Loaded(object sender, RoutedEventArgs e)
        {
            // Get The URI from Previous Page
            if (NavigationContext.QueryString.ContainsKey("file"))
            {
                downloadFile = NavigationContext.QueryString["file"];
                try
                {
                    wc = new System.Net.WebClient();
                    // This Statement is for IMAGE Download
                    wc.OpenReadCompleted += new System.Net.OpenReadCompletedEventHandler(wc_OpenReadCompleted);
                    wc.OpenReadAsync(new Uri(downloadFile));
                    
                    downloadStatus.Text = "Downloading Source from " + downloadFile;
                    downloadResult.Text = string.Empty;
                }
                catch (Exception ex)
                {
                    MessageBox.Show("Connection Error : " + ex.Message);
                }
               
            }
          
        }
 
void wc_OpenReadCompleted(object sender, System.Net.OpenReadCompletedEventArgs e)
        {
            try
            {
                // Read File from Server
                var file = IsolatedStorageFile.GetUserStoreForApplication();
                //downloadFile.Substring(downloadFile.Length,downloadFile.LastIndexOf("/")+1)
 
// First Argument is FILE NAME 
                using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(downloadFile.Substring(downloadFile.Length - (downloadFile.Length - downloadFile.LastIndexOf("/") - 1)), FileMode.Create, file))
                {
                    byte[] buffer = new byte[int.Parse(progressBar.Maximum.ToString())];
                    while (e.Result.Read(buffer, 0, buffer.Length) > 0)
                    {
                        stream.Write(buffer, 0, buffer.Length);
                    }
                    MessageBox.Show("You File " + downloadFile.Substring(downloadFile.Length - (downloadFile.Length - downloadFile.LastIndexOf("/") - 1)) + " Downloaded Successfully.", "Successfully !!", MessageBoxButton.OK);
                }
            }
            catch
            {
               
            }
            
        } 
 
 
void wc_DownloadProgressChanged(object sender, System.Net.DownloadProgressChangedEventArgs e)
        {
            // Progress Changed
            progressBar.Value = e.BytesReceived;
            progressBar.Maximum = e.TotalBytesToReceive;
            downloadResult.Text = "Downloaded  " + (e.BytesReceived / 1048576) + " MB / " + (e.TotalBytesToReceive / 1048576) + " MB. [ " + e.ProgressPercentage.ToString() + " % ].";
        }