C#

Dim _regionManager As IRegion
Dim _container As IUnityContainer
...

Dim mainRegion As IRegion = _regionManager.Regions(RegionNames.MainRegion)
For Each v As View In mainRegion.Views
  mainRegion.Remove(v)
Next
_regionManager.RegisterViewWithRegion(RegionNames.MainRegion, GetType(MaterialView)

IRegion mainRegion = _regionManager.Regions(RegionNames.MainRegion);
for each(var v in mainRegion.Views)
{
  mainRegion.Remove(v);
}
_regionManager.RegisterViewWithRegion(RegionNames.MainRegion, typeof(MaterialView));

Public Property LogoutCommand As ICommand
...
LogoutCommand = New RelayCommand(AddressOf LogoutExecute, AddressOf CanLogoutExecute)

public ICommand LogoutCommand;
...
LogoutCommand = new RelayCommand(LogoutExecute, CanLogoutExecute);
...
private void LogoutExecute(){...}
private bool CanLogoutExecute()
{
 return true;
}
...

public class RelayCommand : ICommand
	{
		private readonly Action<Object> _execute;
		private readonly Predicate<Object> _canExecute;

		public RelayCommand(Action<object> execute): this(execute, null){	}

		public RelayCommand(Action<object> execute, Predicate<Object> canExecute)
		{
			if (execute == null)
			{
				throw new ArgumentException("execute");
			}
			_execute = execute;
			_canExecute = canExecute;
		}

		[DebuggerStepThrough()]
		public bool CanExecute(object parameter)
		{
			return _canExecute == null ? true : _canExecute(parameter);
		}

		public event EventHandler CanExecuteChanged
		{
			add { CommandManager.RequerySuggested += value; }
			remove { CommandManager.RequerySuggested -= value; }
		}

		public void Execute(object parameter)
		{
			_execute(parameter);
		}

	}

	public class RelayCommand<T> : ICommand
	{
		private readonly Action<T> _execute;
		private readonly Predicate<T> _canExecute;

		public RelayCommand(Action<T> execute): this(execute, null){}

		public RelayCommand(Action<T> execute, Predicate<T> canExecute)
		{
			if (execute == null)
			{
				throw new ArgumentException("execute");
			}
		}

		[DebuggerStepThrough()]
		public bool CanExecute(object parameter)
		{
			return _canExecute == null ? true : _canExecute((T)parameter);
		}

		public event EventHandler CanExecuteChanged
		{
			add { CommandManager.RequerySuggested += value; }
			remove { CommandManager.RequerySuggested -= value; }
		}

		public void Execute(object parameter)
		{
			_execute((T) parameter);
		}

	}

using (FileStream fs = File.OpenRead(path))
         {
             //HOW UTILIZE  BeginRead() IS PARAMETR
             fs.BeginRead();
         }

private void loadDataToolStripMenuItem_Click(object sender, EventArgs e)
{
     TabPage tp = new TabPage();
     tp.Text = "Data";
     System.Windows.Forms.CheckedListBox AvailableDataList = new system.Windows.Forms.CheckedListBox();
     AvailableDataList.Dock=DockStyle.Fill;
     tp.Controls.Add(AvailableDataList);

    for (bb = 0; bb < 8; bb++)
    {
        AvailableDataList.Items.Add("Bob");
        switch(SelectName(bb))
        {
            case false:
                AvailableDataList.SetItemChecked(bb, false);
                break;
            case true:
                AvailableDataList.SetItemChecked(bb, true);
        }
    tabControl1.TabPages.Add(tp);
}


private void button4_Click(object sender, EventArgs e)
{
    label1.text = AvailableDataList.Items.Count;
}