//asynchronously: 
await Task.Delay(10000);
 
//synchronously: 
Task.Delay(10000).Wait();

            SharedSetupPar.AppStatus.SO_Type = DeviceInfo.Platform.ToString(); // <-- Android
            SharedSetupPar.AppStatus.DeviceName = Android.OS.Build.Model; // <-- HUAWEI VNS-L31

#region Gestione Permessi
int sdkApi_info = (int)Build.VERSION.SdkInt; // >= 23
bool isAccessDenied = false;
int nrAttempt4Access = 0;
 
do
{
	strErrorMsg = string.Empty;
	if (ContextCompat.CheckSelfPermission(this, Manifest.Permission.ReadExternalStorage) != (int)Permission.Granted)
	{
		strErrorMsg += "\r\nNON Si dispone dei permessi di LETTURA per l'archivio esterno";
		isAccessDenied = true;
	}
	if (ContextCompat.CheckSelfPermission(this, Manifest.Permission.WriteExternalStorage) != (int)Permission.Granted)
	{
		strErrorMsg += "\r\nNON Si dispone dei permessi di SCRITTURA per l'archivio esterno";
		isAccessDenied = true;
	}
	if (isAccessDenied)
	{
		var permissions = new string[]
							{
							Manifest.Permission.ReadExternalStorage,
							Manifest.Permission.WriteExternalStorage
							};
		ActivityCompat.RequestPermissions(this, permissions, 9); // RequestCode REQUEST_FOLDER_PERMISSION = 9?
		Task.Delay(1000).Wait();
	}
	nrAttempt4Access++;
	isAccessDenied = ContextCompat.CheckSelfPermission(this, Manifest.Permission.ReadExternalStorage) != (int)Permission.Granted
				|| ContextCompat.CheckSelfPermission(this, Manifest.Permission.WriteExternalStorage) != (int)Permission.Granted;
} while (isAccessDenied && nrAttempt4Access < 3);
if (isAccessDenied && nrAttempt4Access == 3)
{
	throw new Exception("Permissions are mandatory!\r\n" + strErrorMsg);
}
#endregion

//..
ProgressBar PrgBarIndet;
//..
System.Timers.Timer m_TimerUI;
private static int m_ProgressBarStatus = 0;
object m_lockRsr = new object();
 
protected override void OnCreate(Bundle savedInstanceState)
{
	//.. dopo il codice di inizializzazione standard
	PrgBarIndet = FindViewById<ProgressBar>(Resource.Id.PrgBarIndet);
}
 
public void MetodoDaClessidra()
{
	StartTimer4PrgBar_Test();
	//Azioni lunghe a seguire
}
 
private void StartTimer4PrgBar_Test()
{
	m_ProgressBarStatus = 0;
	PrgBarIndet.Progress = m_ProgressBarStatus;
	PrgBarIndet.Max = 100;
	m_TimerUI = new System.Timers.Timer();
	m_TimerUI.Enabled = true;
	m_TimerUI.Interval = 1000; // 1 secondo
	m_TimerUI.Elapsed += TimerUI_Elapsed_test;
}
 
private void TimerUI_Elapsed_test(object sender, ElapsedEventArgs e)
{
	RunOnUiThread(() =>
	{
		Log.Info(SharedSetupParams.Dbg_AndroidTAG + "TimerUI_Elapsed"
				, string.Format("m_Prg: {0}, PrgBar: {1}"
								, m_ProgressBarStatus, PrgBarIndet.Progress));
		//PrgBar.IncrementProgressBy(10); //Non influenza la proprietà: PrgBar.Progress
		m_ProgressBarStatus += 10;
		PrgBarIndet.Progress = m_ProgressBarStatus; //La proprietà non è influenzata avrà sempre 0!
		CheckProgress_test();
	});
}
 
public void CheckProgress_test()
{
	lock (m_lockRsr)
	{
		Log.Info(SharedSetupParams.Dbg_AndroidTAG + "CheckProgress"
				, string.Format("m_Prg: {0}, PrgBar: {1}, Visible? {2}."
								, m_ProgressBarStatus
								, PrgBarIndet.Progress
								, PrgBarIndet.Visibility == ViewStates.Visible));
		if (m_ProgressBarStatus >= 100) // FA DURARE LA CLESSIDRA 10 SECONDI !!!!!!!!!!!!!!!!
		{
			Log.Info(SharedSetupParams.Dbg_AndroidTAG + "CheckProgress"
					, string.Format("Reset! m_Prg: {0}, PrgBar: {1}"
									, m_ProgressBarStatus, PrgBarIndet.Progress));
			m_ProgressBarStatus = 0;
			PrgBarIndet.Visibility = ViewStates.Gone;
			m_TimerUI.Dispose();
		}
		else
		{
			PrgBarIndet.Visibility = ViewStates.Visible;
		}
	}
}

ImageButton ImgBtnPw4Clipboard;
//..
ImgBtnPw4Clipboard = FindViewById<ImageButton>(Resource.Id.ImgBtnPw4Clipboard);
ImgBtnPw4Clipboard.Touch += ImgBtnPw4Clipboard_Touch;
//..
private async void ImgBtnPw4Clipboard_Touch(object sender, View.TouchEventArgs e)
{
	await Clipboard.SetTextAsync(TxtPw4Clipboard.Text);
}

ListView LVMatchItems = null;
 
//Cambia il Focus per sistemare la situazione odiosa di apertura della tastiera virtuale
LVMatchItems.RequestFocus();

private static bool m_backExitBtnPressed = false; //<-- usato per evitare uscite involontarie dall'App
//...
public override bool OnKeyUp(Keycode keyCode, KeyEvent e)
{
	try
	{
		//Torna alla PAGINA PRINCIPALE
		if (keyCode == Keycode.Back
			&& !m_isMainView)
		{
			SwitchViewMainEdit(true);
			PrepareForNewSearch();
			//Aggiorna la lista e rieseguire l'ordinamento!
			UpdateListView(TxtItemToSearch_FileName.Text);
			return true;
		}
		//Warining per evitare che per errore si esca dall'App!
		else if (keyCode == Keycode.Back
				&& !m_backExitBtnPressed)
		{
			m_backExitBtnPressed = true;    //Sarà ripristinato dopo l'evento: OnPostResume()
			Toast.MakeText(this, "Sure? Try again to EXIT...", ToastLength.Long).Show();
			return true;
		}
		//Mette in Pausa l'App passando dagli eventi: OnPause() ed infine OnStop()
		else if (keyCode == Keycode.Back)
		{
			Log.Warn(SharedSetupParams.Dbg_AndroidTAG + "OnKeyUp"
					, string.Format("KeyCode='{0}'. Messa in PAUSA dell'App!", keyCode));
			this.Finish();
		}
	}
	catch (Exception ex)
	{
		Log.Error(SharedSetupParams.Dbg_AndroidTAG + "OnKeyUp", ex.Message);
	}
	return true;
}
 
protected override void OnPostResume()
{
	if (m_backExitBtnPressed)
	{ 
		m_backExitBtnPressed = false;
	}
	base.OnPostResume();
}

using Xamarin.Essentials;
//...
Button BtnShareFile;
 
protected override void OnCreate(Bundle savedInstanceState)
{
      //...
      BtnShareFile.Click += BtnShareFile_Click;
}
 
private void BtnShareFile_Click(object sender, EventArgs e)
{
      try
      {
          ShareFile();
      }
      catch (Exception ex)
      {
          AManager.MessageBox(this, "BtnShareFile_Click", ex.Message);
      }
}
public async Task ShareFile()
{
      var fn = "Attachment.txt";
      var file = Path.Combine(FileSystem.CacheDirectory, fn);
      File.WriteAllText(file, "Hello World");
 
      await Share.RequestAsync(new ShareFileRequest
      {
            Title = Title,
            File = new ShareFile(file)
      });
}