Xamarin Forms PCL - DatePicker doesn't open correctly on UWP

Hi,

I don't get something, I would like, from a button, open my DatePicker. So I coded that:

private void OnDateClicked(object sender, EventArgs ea)
{
    Debug.WriteLine("PLOPPP");
    //DatePickerControl.IsVisible = true;
    //DatePickerControl.Focus();
    Device.BeginInvokeOnMainThread(() => {
        DatePickerControl.Focus();
    });
}

Once the button got clicked/touched by the user, nothing happens.. Why? I'm just searching to open the Date Selector but I can't figure out why it doesn't work ><

Thank in advance !