次のヘルパーを使用できます
WinRT フライアウト ヘルパー
public class FlyoutHelper
{
protected Popup m_Popup = new Popup();
public Popup Show(Popup popup, FrameworkElement button, double offset = 35d)
{
if (popup == null)
throw new Exception("Popup is not defined");
m_Popup = popup;
if (button == null)
throw new Exception("Button is not defined");
if (double.IsNaN(offset))
throw new Exception("Offset is not defined");
var _Child = popup.Child as FrameworkElement;
if (_Child == null)
throw new Exception("Popup.Child is not defined");
if (double.IsNaN(_Child.Height))
throw new Exception("Popup.Child.Height is not defined");
if (double.IsNaN(_Child.Width))
throw new Exception("Popup.Child.Width is not defined");
// get position of the button
var _Page = Window.Current.Content as Page;
var _Visual = button.TransformToVisual(_Page);
var _Point = _Visual.TransformPoint(new Point(0, 0));
var _Button = new
{
Top = _Point.Y,
Left = _Point.X,
Width = button.ActualWidth,
Height = button.ActualHeight,
};
// determine location
var _TargetTop = (_Button.Top + (_Button.Height / 2)) -
_Child.Height - offset;
var _TargetLeft = (_Button.Left + (_Button.Width / 2)) -
(_Child.Width / 2);
if ((_TargetLeft + _Child.Width) > Window.Current.Bounds.Width)
_TargetLeft = Window.Current.Bounds.Width - _Child.Width - offset;
if (_TargetLeft < 0)
_TargetLeft = offset;
// setup popup
popup.VerticalOffset = _TargetTop;
popup.HorizontalOffset = _TargetLeft;
// add pretty animation(s)
popup.ChildTransitions = new TransitionCollection
{
new EntranceThemeTransition
{
FromHorizontalOffset = 0,
FromVerticalOffset = 20
}
};
// setup
m_Popup.IsLightDismissEnabled = true;
m_Popup.IsOpen = true;
// handle when it closes
m_Popup.Closed -= popup_Closed;
m_Popup.Closed += popup_Closed;
// handle making it close
Window.Current.Activated -= Current_Activated;
Window.Current.Activated += Current_Activated;
// return
return m_Popup;
}
protected void Current_Activated(object sender, WindowActivatedEventArgs e)
{
if (m_Popup == null)
return;
if (e.WindowActivationState == CoreWindowActivationState.Deactivated)
m_Popup.IsOpen = false;
}
protected void popup_Closed(object sender, object e)
{
Window.Current.Activated -= Current_Activated;
if (m_Popup == null)
return;
m_Popup.IsOpen = false;
}
}