如何删除 CompositeWPF/Silverlight 中区域中的所有视图

Question

我想删除 Composite 中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 中崩溃并出现 OutOfRangeException。

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

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

这是我的调用堆栈：

[外部代码]
Microsoft.Practices.Composite.Presentation！Microsoft.Practices.Composite.Presentation.Regions.ViewsCollection.OnCollectionChanged（System.Collections.Specialized.NotifyCollectionChangedEventArgs e = {System.Collections.Specialized.NotifyCollectionChangedEventArgs}) 第 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 发件人 = 计数 = 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 视图 = {Kite.MyApp.SlUI.NavigationRegion.NavigationRegionView}) 线 230 + 0x1b 字节 C#
MyApp.SlUI!Kite.MyApp.SlUI.Components.ViewController.linksRegion_LanguageChanged(对象 发送者= {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(字符串 newLanguage = "en-GB") 第 37 行 + 0x32 字节 C#
MyApp.SlUI!Kite.MyApp.SlUI.Controls.LinksUserControl.ComboBox_SelectionChanged(对象 发送者= {System.Windows.Controls.ComboBox}， System.Windows.Controls.SelectionChangedEventArgs e = {System.Windows.Controls.SelectionChangedEventArgs}) 第 31 行 + 0xb bytes C# [外部代码]

我做错了什么？

PS 在我所在的地区，我有 3 种观点。因此，复合材料在删除第三个时会崩溃。

希望对您有所帮助:)。谢谢。

UPD：我下载了调试符号，发现问题仅出现在 Accordion 控制区域中。 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

如果你只想删除一个，你可以这样做：

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

Answer 2

修改集合时使用 for 循环而不是 foreach

Answer 3

首先检查 _regionManager.Regions["NavigationRegion"] 是否确实存在并且不为 null，如下所示

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 设置不正确，或者存在拼写错误或类似的情况