Basic implementation of ViewPager indicator

ViewPagerIndicator.cs

public class ViewPagerIndicator : LinearLayout, ViewPager.IOnPageChangeListener
{
	private TextView _textView;
	private ViewPager _viewPager;

	#region Android view dafault constructors

	public ViewPagerIndicator(Context context)
		: base(context)
	{
		Init(context);
	}

	public ViewPagerIndicator(Context context, IAttributeSet attrs)
		: base(context, attrs)
	{
		Init(context);
	}

	public ViewPagerIndicator(Context context, IAttributeSet attrs, int defStyleAttr)
		: base(context, attrs, defStyleAttr)
	{
		Init(context);
	}

	public ViewPagerIndicator(Context context, IAttributeSet attrs, int defStyleAttr, int defStyleRes)
		: base(context, attrs, defStyleAttr, defStyleRes)
	{
		Init(context);
	}

	#endregion

	private void Init(Context context)
	{
		_textView = new TextView(context);
		AddView(_textView);
	}

	public void SetViewPager(ViewPager viewPager)
	{
		_viewPager = viewPager;
		_viewPager.AddOnPageChangeListener(this);
	}

	public void OnPageScrolled(int position, float positionOffset, int positionOffsetPixels)
	{
	}

	public void OnPageScrollStateChanged(int state)
	{
	}

	public void OnPageSelected(int position)
	{
		_textView.Text = position.ToString();
	}

	protected override void Dispose(bool disposing)
	{
		base.Dispose(disposing);

		_viewPager?.RemoveOnPageChangeListener(this);
	}
}

viewPagerIndicator.SetViewPager(viewPager);