From 2c8ad03baeab72c4e74ec730ec90d5ed1562c053 Mon Sep 17 00:00:00 2001
From: David Stahl <dstahl@axion-biosystems.com>
Date: Fri, 12 Jun 2020 12:30:54 -0400
Subject: [PATCH] Try to detect when the Visual isn't bound to a
 PresentationSource

---
 .../Position/ControlPositionProvider.cs           | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/Src/ToastNotifications/Position/ControlPositionProvider.cs b/Src/ToastNotifications/Position/ControlPositionProvider.cs
index 7d1b12d..d99f002 100644
--- a/Src/ToastNotifications/Position/ControlPositionProvider.cs
+++ b/Src/ToastNotifications/Position/ControlPositionProvider.cs
@@ -36,8 +36,21 @@ public Point GetPosition(double actualPopupWidth, double actualPopupHeight)
             if (source?.CompositionTarget == null)
                 return new Point(0, 0);
 
+            var elementSource = PresentationSource.FromVisual(_element);
+            if (elementSource == null)
+                return new Point(0, 0);
+
             Matrix transform = source.CompositionTarget.TransformFromDevice;
-            Point location = transform.Transform(_element.PointToScreen(new Point(0, 0)));
+            Point location;
+
+            try
+            {
+                location = transform.Transform(_element.PointToScreen(new Point(0, 0)));
+            }
+            catch (InvalidOperationException)
+            {
+                return new Point(0, 0);
+            }
 
             switch (_corner)
             {