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Hi,
That's great! Thanks!
I'm trying your fix but the problem now is bigger.
On iOS when the page opens I remove the gauge from RelativeLayout and add again to fit the screen on OnSizeAllocated.
When I call the Children.Remove passing a control with a SFGauge inside, it give me a NullReferenceException
Can you take a look please, now it's unusable.
Thanks
Your example, works I can't reproduce my problem in your example, but may with this info you could find the problem:
- I'm using a custom control with a SFGauge in a library project
- In my page (in Xamarin Forms project) there is 2 instaces of this control, so 2 SFGauges will appear in the page
- I'm removing the control from the RelativeLayout on OnSizeAllocated, to reposition it when user rotate the screen.
Here is the error stack:
System.NullReferenceException: Object reference not set to an instance of an object
at Syncfusion.SfGauge.iOS.SFCircularGauge.MovedToSuperview () [0x00024] in <7845f32627aa48f38bf0ab603ff23021>:0
at at (wrapper managed-to-native) ObjCRuntime.Messaging:void_objc_msgSendSuper (intptr,intptr)
at UIKit.UIView.RemoveFromSuperview () [0x0002a] in /Users/builder/data/lanes/4991/4a279c9a/source/xamarin-macios/src/build/ios/native/UIKit/UIView.g.cs:1402
at Syncfusion.SfGauge.XForms.iOS.SfGaugeRenderer.OnElementChanged (Xamarin.Forms.Platform.iOS.ElementChangedEventArgs`1[TElement] e) [0x0001d] in <1e565a9d2e9241cb9583a4173f856caa>:0
at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].SetElement (TElement element) [0x00118] in <710620a3d4a94be99b29618147548b59>:0
at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Dispose (System.Boolean disposing) [0x0007b] in <710620a3d4a94be99b29618147548b59>:0
at Xamarin.Forms.Platform.iOS.ViewRenderer`2[TView,TNativeView].Dispose (System.Boolean disposing) [0x00000] in <710620a3d4a94be99b29618147548b59>:0
at Foundation.NSObject.Dispose () [0x00000] in /Users/builder/data/lanes/4991/4a279c9a/source/xamarin-macios/src/Foundation/NSObject2.cs:133
at Xamarin.Forms.Platform.iOS.Platform.DisposeModelAndChildrenRenderers (Xamarin.Forms.Element view) [0x00038] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\Platform.cs:231
at Xamarin.Forms.Platform.iOS.Platform.HandleChildRemoved (System.Object sender, Xamarin.Forms.ElementEventArgs e) [0x00007] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\Platform.cs:342
at Xamarin.Forms.Element.OnDescendantRemoved (Xamarin.Forms.Element child) [0x00008] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:601
at Xamarin.Forms.Element.OnDescendantRemoved (Xamarin.Forms.Element child) [0x00022] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:604
at Xamarin.Forms.Element.OnDescendantRemoved (Xamarin.Forms.Element child) [0x00022] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:604
at Xamarin.Forms.Element.OnDescendantRemoved (Xamarin.Forms.Element child) [0x00022] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:604
at Xamarin.Forms.Element.OnDescendantRemoved (Xamarin.Forms.Element child) [0x00022] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:604
at Xamarin.Forms.Element.OnChildRemoved (Xamarin.Forms.Element child) [0x00021] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:368
at Xamarin.Forms.VisualElement.OnChildRemoved (Xamarin.Forms.Element child) [0x00000] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\VisualElement.cs:578
at Xamarin.Forms.Layout`1[T].OnChildRemoved (Xamarin.Forms.Element child) [0x00000] in <0f1ce60dbc6b4e24af01294c7acf41c6>:0
at Xamarin.Forms.Layout.OnInternalRemoved (Xamarin.Forms.View view) [0x00012] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\Layout.cs:417
at Xamarin.Forms.Layout.InternalChildrenOnCollectionChanged (System.Object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x0002f] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\Layout.cs:381
at at (wrapper delegate-invoke) <Module>:invoke_void_object_NotifyCollectionChangedEventArgs (object,System.Collections.Specialized.NotifyCollectionChangedEventArgs)
at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x0000f] in <3d3bed331af843baa5877f5ed09f45e1>:0
at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedAction action, System.Object item, System.Int32 index) [0x00009] in <3d3bed331af843baa5877f5ed09f45e1>:0
at System.Collections.ObjectModel.ObservableCollection`1[T].RemoveItem (System.Int32 index) [0x0002b] in <3d3bed331af843baa5877f5ed09f45e1>:0
at System.Collections.ObjectModel.Collection`1[T].Remove (T item) [0x00027] in <5fd075b6ff6143c68dcfdd192b8757c5>:0
at Xamarin.Forms.ObservableWrapper`2[TTrack,TRestrict].Remove (TRestrict item) [0x00035] in <0f1ce60dbc6b4e24af01294c7acf41c6>:0
at Rabbit2.Pages.NavigationTrip.OnSizeAllocated (System.Double width, System.Double height) [0x00081] in /Users/joaofortes/dev/Rabbit/Rabbit2/Rabbit2/Rabbit2/Pages/NavigationTrip.xaml.cs:60
at Xamarin.Forms.VisualElement.SizeAllocated (System.Double width, System.Double height) [0x00000] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\VisualElement.cs:629
at Xamarin.Forms.VisualElement.SetSize (System.Double width, System.Double height) [0x00021] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\VisualElement.cs:773
at Xamarin.Forms.VisualElement.set_Bounds (Xamarin.Forms.Rectangle value) [0x0005d] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\VisualElement.cs:157
at Xamarin.Forms.VisualElement.Layout (Xamarin.Forms.Rectangle bounds) [0x00000] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\VisualElement.cs:511
at Xamarin.Forms.MasterDetailPage.Xamarin.Forms.IMasterDetailPageController.set_DetailBounds (Xamarin.Forms.Rectangle value) [0x0001a] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\MasterDetailPage.cs:105
at Xamarin.Forms.Platform.iOS.TabletMasterDetailRenderer.ViewDidLayoutSubviews () [0x00085] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\Renderers\TabletMasterDetailRenderer.cs:193
at at (wrapper managed-to-native) UIKit.UIApplication:UIApplicationMain (int,string[],intptr,intptr)
at UIKit.UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate) [0x00005] in /Users/builder/data/lanes/4991/4a279c9a/source/xamarin-macios/src/UIKit/UIApplication.cs:79
at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x00038] in /Users/builder/data/lanes/4991/4a279c9a/source/xamarin-macios/src/UIKit/UIApplication.cs:63
at Rabbit2.iOS.Application.Main (System.String[] args) [0x00001] in /Users/joaofortes/dev/Rabbit/Rabbit2/Rabbit2/Rabbit2.iOS/Main.cs:17
attached is a project where you can see the problem. It's on about page.
solved! Thanks!
