fix(calendarview): fixed potential NRE when unloaded before being ful…

…ly initialized
unoplatform · Jun 7, 2021 · 34657f0 · 34657f0
1 parent 6149f9b
commit 34657f0
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Showing 2 changed files with 6 additions and 6 deletions.
diff --git a/src/Uno.UI/UI/Xaml/Controls/CalendarView/CalendarViewGeneratorHost.cs b/src/Uno.UI/UI/Xaml/Controls/CalendarView/CalendarViewGeneratorHost.cs
@@ -703,15 +703,15 @@ internal void AttachVisibleIndicesUpdatedEvent()
 
 		internal void DetachVisibleIndicesUpdatedEvent()
 		{
-			if (m_epVisibleIndicesUpdatedHandler is {})
+			if (m_epVisibleIndicesUpdatedHandler is {} && m_tpPanel is {})
 			{
 				m_tpPanel.VisibleIndicesUpdated -= m_epVisibleIndicesUpdatedHandler;
 			}
 		}
 
 		internal void AttachScrollViewerFocusEngagedEvent()
 		{
-			if (m_tpPanel is { })
+			if (m_tpPanel is { } && m_tpScrollViewer is { })
 			{
 				ScrollViewer sv = (m_tpScrollViewer as ScrollViewer);
 				m_epScrollViewerFocusEngagedEventHandler ??= new ControlFocusEngagedEventCallback(
@@ -728,7 +728,7 @@ internal void AttachScrollViewerFocusEngagedEvent()
 
 		internal void DetachScrollViewerFocusEngagedEvent()
 		{
-			if (m_epScrollViewerFocusEngagedEventHandler is {})
+			if (m_epScrollViewerFocusEngagedEventHandler is {} && m_tpScrollViewer is {})
 			{
 				m_tpScrollViewer.FocusEngaged -= m_epScrollViewerFocusEngagedEventHandler;
 			}

diff --git a/src/Uno.UI/UI/Xaml/Controls/CalendarView/CalendarView_Partial.cs b/src/Uno.UI/UI/Xaml/Controls/CalendarView/CalendarView_Partial.cs
@@ -1251,15 +1251,15 @@ private void AttachButtonClickedEvents()
 
 		private void DetachButtonClickedEvents()
 		{
-			if (m_epHeaderButtonClickHandler is { })
+			if (m_epHeaderButtonClickHandler is { } && m_tpHeaderButton is {})
 			{
 				m_tpHeaderButton.Click -= m_epHeaderButtonClickHandler;
 			}
-			if (m_epPreviousButtonClickHandler is {})
+			if (m_epPreviousButtonClickHandler is {} && m_tpPreviousButton is {})
 			{
 				m_tpPreviousButton.Click -= m_epPreviousButtonClickHandler;
 			}
-			if (m_epNextButtonClickHandler is {})
+			if (m_epNextButtonClickHandler is {} && m_tpNextButton is {})
 			{
 				m_tpNextButton.Click -= m_epNextButtonClickHandler;
 			}