protected override void OnAttached()
{
_textView = Control as UITextView;
_placeholderLabel = new UILabel();
_placeholderLabel.LineBreakMode = UILineBreakMode.WordWrap;
_placeholderLabel.Lines = 0;
_placeholderLabel.Font = _textView.Font;
_placeholderLabel.BackgroundColor = UIColor.Clear;
_placeholderLabel.Alpha = 0;
UpdateText();
UpdateColor();
_textView.AddSubview(_placeholderLabel);
_placeholderLabel.TranslatesAutoresizingMaskIntoConstraints = false;
_placeholderLabel.TopAnchor.ConstraintEqualTo(_textView.TopAnchor, 8).Active = true;
_placeholderLabel.LeftAnchor.ConstraintEqualTo(_textView.LeftAnchor, 4).Active = true;
_placeholderLabel.RightAnchor.ConstraintEqualTo(_textView.RightAnchor, 4).Active = true;
_placeholderLabel.WidthAnchor.ConstraintEqualTo(_textView.WidthAnchor, 1, -8).Active = true;
_textView.SendSubviewToBack(_placeholderLabel);
if (_textView.Text.Length == 0 && _placeholderLabel.Text.Length > 0)
{
_placeholderLabel.Alpha = 1;
}
_textView.Changed += _textView_Changed;
}