Xamarin: Download a file with ProgressBar

This recipe shows how to download a file using WebClient in Xamarin.Android.

To download a file (.mp3, etc.) follow these steps:

• Add new using statements to your code:

  using Java.IO;
  using System.IO;
  using System.Net;
  

• Create a WebClient object:

  var webClient=new WebClient();
  

• Create the URL for the files to download:

  var url=new Uri("http://8morning.com/demo/wp-content/uploads/2016/04/hoc-photoshop.jpg");
  

• Create the array for contains the length of a file.

  byte[] bytes=null;
  

  Add an event handler that will execute when the download is complete. Create a ProgressDialog to show a progress indicator and an optional text message.

  webClient.DownloadProgressChanged+= WebClient_DownloadProgressChanged;
  
  
              dialog = new ProgressDialog (this);
              dialog.SetProgressStyle (ProgressDialogStyle.Horizontal);// style is horizontal
              dialog.SetTitle("Downloading...");
              dialog.SetCancelable (false);
              //dialog.SetButton("Cancel",);
              dialog.SetCanceledOnTouchOutside (false); //if it is true. When you touch anywhere lie outside the dialog-> dialog will be close.
              dialog.Show ();// showing a dialog
   
              try
              {
                  bytes= await webClient.DownloadDataTaskAsync(url);
              }
              catch(TaskCanceledException)
              {
                  Toast.MakeText(this,"Task Canceled!",ToastLength.Long).Show();
                  return;
              }
              catch(Exception a)
              {
                  Toast.MakeText(this,a.InnerException.Message,ToastLength.Long).Show();
                  dialog.Progress=0;
                  return;
              }
  

  var documentsPath=Android.OS.Environment.ExternalStorageDirectory+"/Download"; // The direction is Download folder in Device store. A file will be save here.
              string localFilename = Name your file +".jpg";
              string localPath=System.IO.Path.Combine(documentsPath,localFilename);// documentsPath +"/"+ localFilename
              
   
              dialog.SetTitle("Download Complete");//
   
              //Save the Mp3 using writeAsync
              FileStream fs=new FileStream(localPath,FileMode.OpenOrCreate);
              
              await fs.WriteAsync (bytes, 0, bytes.Length);// writes to Download folder 
              fs.Close ();
   
   
              dialog.Progress = 0;
  

• In event`` ``WebClient_DownloadProgressChanged will execute progress when a file is downloading.

  void WebClient_DownloadProgressChanged (object sender, DownloadProgressChangedEventArgs e)
          {
              dialog.Progress = e.ProgressPercentage;
              if (e.ProgressPercentage == 100) {
                  dialog.Hide ();
              }
          }
  

Sample

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