<VerticalStackLayout>
		<Button Text="Hide Keyboard" Clicked="Button_Clicked" />
		<telerik:RadNumericMaskedEntry x:Name="numeric" />
	</VerticalStackLayout>

private void Button_Clicked(object sender, EventArgs e)
	{
		var textInput = ChildOfType<RadEntry>(this.numeric);
		if (textInput != null)
		{
			textInput.Focus();
		}
	}

	internal static T ChildOfType<T>(View visualElement) where T : View
	{
		if (visualElement == null)
		{
			return null;
		}

		foreach (var item in VisualTreeElementExtensions.GetVisualTreeDescendants(visualElement))
		{
			if (item is T targetElement)
			{
				return targetElement;
			}
		}

		return null;
	}