Question

我想在Composite中删除我所在区域的所有视图。我正在使用Silverlight 4.0。

不幸的是，这段代码在Composite内部与OutOfRangeException崩溃。

        List<object> views = new List<object>(_regionManager.Regions["NavigationRegion"].Views);

        foreach (object view in views)
        {
            _regionManager.Regions["NavigationRegion"].Remove(view);
        }

这是我的callstack：

[外部代码]
  Microsoft.Practices.Composite.Presentation！Microsoft.Practices.Composite.Presentation.Regions.ViewsCollection.OnCollectionChanged（System.Collections.Specialized.NotifyCollectionChangedEventArgs   e = {System.Collections.Specialized.NotifyCollectionChangedEventArgs}）   102行+ 0x24字节C＃
  Microsoft.Practices.Composite.Presentation！Microsoft.Practices.Composite.Presentation.Regions.ViewsCollection.RemoveAndNotify（System.Collections.IList   items = Count = 1）第45行+ 0x2b字节C＃
  Microsoft.Practices.Composite.Presentation！Microsoft.Practices.Composite.Presentation.Regions.ViewsCollection.UnderlyingCollection_CollectionChanged（对象   sender = Count = 0，   System.Collections.Specialized.NotifyCollectionChangedEventArgs e =   {System.Collections.Specialized.NotifyCollectionChangedEventArgs}）   第153行+ 0xb字节C＃[外部代码]
  Microsoft.Practices.Composite.Presentation！Microsoft.Practices.Composite.Presentation.Regions.Region.Remove（对象   view = {Kite.MyApp.SlUI.NavigationRegion.NavigationRegionView}）Line   230 + 0x1b字节C＃
  MyApp.SlUI！Kite.MyApp.SlUI.Components.ViewController.linksRegion_LanguageChanged（对象   sender = {Kite.MyApp.SlUI.Controls.LinksUserControl}，   Kite.MyApp.SlUI.Common.EventArgs e =   {Kite.MyApp.SlUI.Common.EventArgs}）第77行+ 0x2d字节C＃
  MyApp.SlUI！Kite.MyApp.SlUI.Controls.LinksUserControl.OnLanguageChanged（串   newLanguage =“en-GB”）第37行+ 0x32字节C＃
  MyApp.SlUI！Kite.MyApp.SlUI.Controls.LinksUserControl.ComboBox_SelectionChanged（对象   sender = {System.Windows.Controls.ComboBox}，   System.Windows.Controls.SelectionChangedEventArgs e =   {System.Windows.Controls.SelectionChangedEventArgs}）第31行+ 0xb   字节C＃[外部代码]

我错了什么？

P.S。在我的地区，我有3个观点。因此，复合体在删除第三个时崩溃了。

希望你帮忙:)。谢谢。

UPD：我下载了调试符号，发现问题仅在Accordion控件中作为区域。这是完整的调用堆栈：

mscorlib.dll!System.ThrowHelper.ThrowArgumentOutOfRangeException(System.ExceptionArgument argument, System.ExceptionResource resource) + 0x41 bytes 
mscorlib.dll!System.ThrowHelper.ThrowArgumentOutOfRangeException() + 0x10 bytes 
mscorlib.dll!System.Collections.Generic.List<object>.this[int].get(int index = 0) + 0x13 bytes  
System.Windows.dll!System.Windows.Controls.ItemCollection.GetItemImpl(int index) + 0x15 bytes   
System.Windows.dll!System.Windows.Controls.ItemCollection.GetItemImplSkipMethodPack(int index) + 0xb bytes  
System.Windows.dll!System.Windows.PresentationFrameworkCollection<System.__Canon>.this[int].get(int index) + 0xb bytes  
System.Windows.Controls.Layout.Toolkit!System.Windows.Controls.Accordion.UnselectItem(int index = 0, object item = null) + 0x1aa bytes  
System.Windows.Controls.Layout.Toolkit!System.Windows.Controls.Accordion.ChangeSelectedIndex(int oldIndex = 0, int newIndex = -1) + 0x14c bytes 
System.Windows.Controls.Layout.Toolkit!System.Windows.Controls.Accordion.OnSelectedIndexPropertyChanged(System.Windows.DependencyObject d = {System.Windows.Controls.Accordion}, System.Windows.DependencyPropertyChangedEventArgs e = {System.Windows.DependencyPropertyChangedEventArgs}) + 0x1d9 bytes   
System.Windows.dll!System.Windows.DependencyObject.RaisePropertyChangeNotifications(System.Windows.DependencyProperty dp = {System.Windows.CustomDependencyProperty}, object oldValue, object newValue) + 0x51 bytes    
System.Windows.dll!System.Windows.DependencyObject.UpdateEffectiveValue(System.Windows.DependencyProperty property, System.Windows.EffectiveValueEntry oldEntry, ref System.Windows.EffectiveValueEntry newEntry, System.Windows.DependencyObject.ValueOperation operation) + 0xf5 bytes    
System.Windows.dll!System.Windows.DependencyObject.SetValueInternal(System.Windows.DependencyProperty dp, object value, bool allowReadOnlySet) + 0x2ad bytes    
System.Windows.dll!System.Windows.DependencyObject.SetValue(System.Windows.DependencyProperty dp, object value) + 0xb bytes 
System.Windows.Controls.Layout.Toolkit!System.Windows.Controls.Accordion.SelectedIndex.set(int value = -1) + 0x4d bytes 
System.Windows.Controls.Layout.Toolkit!System.Windows.Controls.Accordion.OnItemsChanged(System.Collections.Specialized.NotifyCollectionChangedEventArgs e = {System.Collections.Specialized.NotifyCollectionChangedEventArgs}) + 0x737 bytes    
System.Windows.dll!System.Windows.Controls.ItemsControl.OnItemCollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) + 0x52 bytes  
System.Windows.dll!System.Windows.Controls.ItemCollection.NotifyCollectionChanged(System.Collections.Specialized.NotifyCollectionChangedEventArgs e) + 0x37 bytes   
System.Windows.dll!System.Windows.Controls.ItemCollection.NotifyItemsCollectionChanged(System.Collections.Specialized.NotifyCollectionChangedEventArgs e) + 0x1f bytes  
System.Windows.dll!System.Windows.Controls.ItemCollection.EnumerableCollectionView.System.Windows.Controls.ICollectionChangedListener.OnCollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) + 0x4f bytes    
System.Windows.dll!System.Windows.Controls.WeakCollectionChangedListener.SourceCollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) + 0x3d bytes 
Microsoft.Practices.Composite.Presentation!Microsoft.Practices.Composite.Presentation.Regions.ViewsCollection.OnCollectionChanged(System.Collections.Specialized.NotifyCollectionChangedEventArgs e = {System.Collections.Specialized.NotifyCollectionChangedEventArgs}) Line 102 + 0x24 bytes  C#
Microsoft.Practices.Composite.Presentation!Microsoft.Practices.Composite.Presentation.Regions.ViewsCollection.RemoveAndNotify(System.Collections.IList items = Count = 1) Line 45 + 0x2b bytes  C#
Microsoft.Practices.Composite.Presentation!Microsoft.Practices.Composite.Presentation.Regions.ViewsCollection.UnderlyingCollection_CollectionChanged(object sender = Count = 0, System.Collections.Specialized.NotifyCollectionChangedEventArgs e = {System.Collections.Specialized.NotifyCollectionChangedEventArgs}) Line 153 + 0xb bytes C#
System.Windows.dll!System.Collections.ObjectModel.ObservableCollection<Microsoft.Practices.Composite.Presentation.Regions.ItemMetadata>.OnCollectionChanged(System.Collections.Specialized.NotifyCollectionChangedEventArgs e) + 0x37 bytes 
System.Windows.dll!System.Collections.ObjectModel.ObservableCollection<System.__Canon>.RemoveItem(int index) + 0xa1 bytes   
mscorlib.dll!System.Collections.ObjectModel.Collection<Microsoft.Practices.Composite.Presentation.Regions.ItemMetadata>.Remove(Microsoft.Practices.Composite.Presentation.Regions.ItemMetadata item) + 0x75 bytes   
Microsoft.Practices.Composite.Presentation!Microsoft.Practices.Composite.Presentation.Regions.Region.Remove(object view = {Kite.MyApp.SlUI.NavigationRegion.NavigationRegionView}) Line 230 + 0x1b bytes    C#

Answer 1

首先检查_regionManager.Regions [“NavigationRegion”]是否确实存在且非空如此

if (_regionManager.Regions["NavigationRegion"] != null)
{
        List<object> views = new List<object>(_regionManager.Regions["NavigationRegion"].Views);

        foreach (object view in views)
        {
            _regionManager.Regions["NavigationRegion"].Remove(view);
        }
}

可能是NavigationRegion没有正确设置，或者有拼写错误或类似的东西

Answer 2

在修改集合时使用for循环而不是foreach

Answer 3

如果你只想删除一个，你可以这样做：

 _regionManager.Regions["NavigationRegion"].Remove(
                    _regionManager.Regions["NavigationRegion"].GetView("viewName"));

如何在CompositeWPF / Silverlight中删除区域中的所有视图

3 个答案: