C# 内容视图内容更新应用程序在xamarin iOS中崩溃

我创建了xamarin表单项目并多次更新内容视图内容

它正确地更新了android。但它不适用于iOS

我已经更新了Contentview的内容，当我点击这样的按钮时

contentView.content = mVview;

请找到堆栈跟踪

wrapper managed-to-native


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/3969/7beaef43/source/xamarin-macios/src/UIKit/UIApplication.cs:79 
  at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName,`/lanes/3969/7beaef43/source/xamarin-macios/src/UIKi1

当我放try catch时，我得到了这个堆栈跟踪

 at Xamarin.Forms.Platform.iOS.EditorRenderer.Dispose (System.Boolean disposing) [0x00003] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\Renderers\EditorRenderer.cs:28 
  at Foundation.NSObject.Dispose () [0x00000] in /Users/builder/data/lanes/3969/7beaef43/source/xamarin-macios/src/Foundation/NSObject2.cs:133 
  at Xamarin.Forms.Platform.iOS.ListViewRenderer.Dispose (System.Boolean disposing) [0x001c4] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\Renderers\ListViewRenderer.cs:153 
  at Foundation.NSObject.Dispose () [0x00000] in /Users/builder/data/lanes/3969/7beaef43/source/xamarin-macios/src/Foundation/NSObject2.cs:133 
  at Xamarin.Forms.Platform.iOS.Platform.DisposeModelAndChildrenRenderers (Xamarin.Forms.Element view) [0x00038] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\Platform.cs:322 
  at Xamarin.Forms.Platform.iOS.Platform.HandleChildRemoved (System.Object sender, Xamarin.Forms.ElementEventArgs e) [0x00007] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\Platform.cs:433 
  at Xamarin.Forms.Element.OnDescendantRemoved (Xamarin.Forms.Element child) [0x00008] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:600 
  at Xamarin.Forms.Element.OnDescendantRemoved (Xamarin.Forms.Element child) [0x00022] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:603 
  at Xamarin.Forms.Element.OnDescendantRemoved (Xamarin.Forms.Element child) [0x00022] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:603 
  at Xamarin.Forms.Element.OnChildRemoved (Xamarin.Forms.Element child) [0x00021] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:367 
  at Xamarin.Forms.VisualElement.OnChildRemoved (Xamarin.Forms.Element child) [0x00000] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\VisualElement.cs:578 
  at Xamarin.Forms.Layout.OnInternalRemoved (Xamarin.Forms.View view) [0x00012] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\Layout.cs:413 
  at Xamarin.Forms.Layout.InternalChildrenOnCollectionChanged (System.Object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x0002f] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\Layout.cs:377 
  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x00012] in /Users/builder/data/lanes/3969/7beaef43/source/xamarin-macios/_ios-build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/mcs/class/referencesource/System/compmod/system/collections/objectmodel/observablecollection.cs:288 
  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedAction action, System.Object item, System.Int32 index) [0x00000] in /Users/builder/data/lanes/3969/7beaef43/source/xamarin-macios/_ios-build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/mcs/class/referencesource/System/compmod/system/collections/objectmodel/observablecollection.cs:351 
  at System.Collections.ObjectModel.ObservableCollection`1[T].RemoveItem (System.Int32 index) [0x0002b] in /Users/builder/data/lanes/3969/7beaef43/source/xamarin-macios/_ios-build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/mcs/class/referencesource/System/compmod/system/collections/objectmodel/observablecollection.cs:205 
  at System.Collections.ObjectModel.Collection`1[T].Remove (T item) [0x0002d] in /Users/builder/data/lanes/3969/7beaef43/source/xamarin-macios/_ios-build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/mcs/class/referencesource/mscorlib/system/collections/objectmodel/collection.cs:113 
  at Xamarin.Forms.TemplateUtilities.OnContentChanged (Xamarin.Forms.BindableObject bindable, System.Object oldValue, System.Object newValue) [0x0001a] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\TemplateUtilities.cs:63 
  at Xamarin.Forms.BindableObject.SetValueActual (Xamarin.Forms.BindableProperty property, Xamarin.Forms.BindableObject+BindablePropertyContext context, System.Object value, System.Boolean currentlyApplying, Xamarin.Forms.BindableObject+SetValueFlags attributes, System.Boolean silent) [0x00108] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\BindableObject.cs:584 
  at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.BindableObject+SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes) [0x0014b] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\BindableObject.cs:378 
  at Xamarin.Forms.BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value, System.Boolean fromStyle, System.Boolean checkAccess) [0x0005f] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\BindableObject.cs:531 
  at Xamarin.Forms.BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value) [0x00000] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\BindableObject.cs:83 
  at Xamarin.Forms.ContentView.set_Content (Xamarin.Forms.View value) [0x00000] in C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\ContentView.cs:11 
  at EgnatiumFull.Pages.QuestionAnswerPage.UpdateTheQuestionLayout () [0x00144] in /Volumes/MS/prjects/Egnatium/EgnatiumFinal/EgnatiumFinal/EgnatiumFinal/Pages/QuestionAnswerPage.cs:539 
  at EgnatiumFull.Pages.QuestionAnswerPage+<OnAppearing>c__async1.MoveNext () [0x0007e] in /Volumes/MS/prjects/Egnatium/EgnatiumFinal/EgnatiumFinal/EgnatiumFinal/Pages/QuestionAnswerPage.cs:383 
--- End of stack trace from previous location where exception was thrown ---
  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/3969/7beaef43/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/3969/7beaef43/source/xamarin-macios/src/UIKit/UIApplication.cs:63 
  at EgnatiumFinal.iOS.Application.Main (System.String[] args) [0x00008] in /Users/saifamily/Documents/14_2_17/EgnatiumFinal/EgnatiumFinal/EgnatiumFinal.iOS/Main.cs:17 xa

C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\renders\EditorRenderer.cs:28中的Xamarin.Forms.Platform.iOS.EditorRenderer.Dispose（System.Boolean disposing）[0x00003]中的

在Studio.NSObjut.DISTABLE（）0[0x0000 ]中/用户/生成器/数据/通道/ 3969 /7BeaEF43/源/ XAMARIN MACSI/SRC/N粉底/NSObjut2.Cs: 133
位于C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\renders\ListViewRenderer.cs:153中的Xamarin.Forms.Platform.iOS.ListViewRenderer.Dispose（System.Boolean disposing）[0x001c4]
在Studio.NSObjut.DISTABLE（）0[0x0000 ]中/用户/生成器/数据/通道/ 3969 /7BeaEF43/源/ XAMARIN MACSI/SRC/N粉底/NSObjut2.Cs: 133
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\Platform.disposemodelandchildrenderers（Xamarin.Forms.Element视图）[0x00038]中
位于C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\Platform.iOS\Platform.cs:433中的Xamarin.Forms.Platform.HandleChildRemoved（System.Object sender，Xamarin.Forms.ElementEventArgs e）[0x00007]
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:600中的Xamarin.Forms.Element.OnDescendantRemoved（Xamarin.Forms.Element子项）[0x00008]处
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:603中的Xamarin.Forms.Element.OnDescendantRemoved（Xamarin.Forms.Element子项）[0x00022]处
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:603中的Xamarin.Forms.Element.OnDescendantRemoved（Xamarin.Forms.Element子项）[0x00022]处
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:367中的Xamarin.Forms.Element.OnChildRemoved（Xamarin.Forms.Element子项）[0x00021]处
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\VisualElement.cs:578中的Xamarin.Forms.VisualElement.OnChildRemoved（Xamarin.Forms.Element子元素）[0x00000]中
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\Layout.cs:413中的Xamarin.Forms.Layout.OnInternalRemoved（Xamarin.Forms.View视图）[0x00012]中
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\Layout.cs:377中的Xamarin.Forms.Layout.InternalChildrenOnCollectionChanged（System.Object sender，System.Collections.Specialized.NotifyCollectionChangedEventArgs e）[0x0002f]处
位于System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged（System.Collections.Specialized.NotifyCollectionChangedEventArgs e）[0x00012]在/Users/builder/data/lanes/3969/7beaef43/source/xamarin macios/_ios-build/Library/Frameworks/xamarin.ios.framework/Versions/git/src/mono/mcs/class/referencesource/System/compmod/System/collections/objectmodel/observecollection.cs:288中
位于System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged（System.Collections.Specialized.NotifyCollectionChangedAction，System.Object项，System.Int32索引）[0x00000]在/Users/builder/data/lanes/3969/7beaef43/source/xamarin macios/_ios-build/Library/Frameworks/xamarin.ios.framework/Versions/git/src/mono/mcs/class/referencesource/System/compmod/System/collections/objectmodel/observecollection.cs:351中
在/Users/builder/data/lanes/3969/7beaef43/source/xamarin-macios/_-ios-build/Library/Frameworks/xamarin.ios.Frameworks/git/src/mono/mcs/class/referencesource/System/compmod/System/Collections/ObjectModel/observecollection.cs:205中的System.Collections.ObjectModel.ObservableCollection`1[T]
在/Users/builder/data/lanes/3969/7beaef43/source/xamarin-macios/_-ios-build/Library/Frameworks/xamarin.ios.framework/Versions/git/src/mono/mcs/class/referencesource/mscorlib/System/Collections/ObjectModel/Collection.cs:113中的System.Collection
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\TemplateUtilities.cs:63中的Xamarin.Forms.TemplateUtilities.OnContentChanged（Xamarin.Forms.BindableObject-bindable，System.Object-oldValue，System.Object-newValue）[0x0001a]
在Xamarin.Forms.BindableObject.SetValueActual（Xamarin.Forms.BindableProperty属性，Xamarin.Forms.BindableObject+BindablePropertyContext上下文，System.Object值，System.Boolean当前应用，Xamarin.Forms.BindableObject+SetValueFlags属性，System.Boolean静默）[0x00108]在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\BindableObject.cs:584中
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.BindableObject+SetValueFlags-attributes，Xamarin.Forms.BindableObject.SetValueCore（Xamarin.Forms.BindableObject属性，System.Object值，Xamarin.Forms.BindableObject+SetValuePrivateFlags-privateAttributes，Xamarin.Forms.BindableObject+SetValuePrivateFlags-privateAttributes）[0x0014b]中
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\BindableObject.cs:531中的Xamarin.Forms.BindableObject.SetValue（Xamarin.Forms.BindableProperty属性，System.Object值，System.Boolean fromStyle，System.Boolean checkAccess）[0x0005f]处
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\BindableObject.cs:83中的Xamarin.Forms.BindableObject.SetValue（Xamarin.Forms.BindableProperty属性，System.Object值）[0x00000]处
在C:\BuildAgent2\work\ca3766cfc22354a1\Xamarin.Forms.Core\ContentView.cs:11中的Xamarin.Forms.ContentView.set_内容（Xamarin.Forms.View值）[0x00000]
在/Volumes/MS/prjects/Egnatium/EgnatiumFinal/EgnatiumFinal/EgnatiumFinal/EgnatiumFinal/Pages/QuestionAnswerPage.cs:539中的EgnatiumFull.Pages.QuestionAnswerPage.UpdateTheQuestionLayout（）[0x00144]
在/Volumes/MS/prjects/Egnatium/Eg中的EgnatiumFull.Pages.QuestionAnswerPage+c_uasync1.MoveNext（）[0x0007e]
 protected override void Dispose() 
    {
        try{
        base.Dispose();
         }
       Catch(Exception ex)
         {
            return;
         }
    }