windows-phone-7 – 为什么我从LongListSelector下载时收到“格

我试图从Silverlight工具包LongListSelector创建一个后代类.我们称之为SimpleLonglistSelector.我从“Silverlight for Windows Phone Toolkit Source& Sample – Feb 2011.zip”开始.

http://silverlight.codeplex.com/releases/view/60291

我创建了一个新课程：

public class SimpleLongListSelector : LongListSelector
{
    public SimpleLongListSelector()
    {
        var itemsPanelTemplate = @"
            <ItemsPanelTemplate xmlns='http://schemas.microsoft.com/client/2007'>
                <toolkit:WrapPanel xmlns:toolkit='clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls.Toolkit' Orientation=""Horizontal""/>
            </ItemsPanelTemplate>";

        this.GroupItemsPanel = (ItemsPanelTemplate)XamlReader.Load(itemsPanelTemplate);

        var groupItemTemplate = @"
            <DataTemplate xmlns='http://schemas.microsoft.com/client/2007'>
                <Border Width=""99"" Height=""99"" Background=""{StaticResource PhoneAccentBrush}"" Margin=""6"" IsHitTestVisible=""{Binding HasItems}"">
                    <TextBlock Text=""{Binding Key}"" 
                                           FontFamily=""{StaticResource PhoneFontFamilySemiBold}""
                                           FontSize=""36""
                                           Margin=""{StaticResource PhoneTouchTargetOverhang}""
                                           Foreground=""{StaticResource PhoneForegroundBrush}""                                        
                                           VerticalAlignment=""Bottom""/>
                </Border>
            </DataTemplate>";

        this.GroupItemTemplate = (DataTemplate)XamlReader.Load(groupItemTemplate);

        var groupHeaderTemplate = @"
            <DataTemplate xmlns='http://schemas.microsoft.com/client/2007'>
                <Border Background=""Transparent"">
                    <Border Background=""{StaticResource PhoneAccentBrush}"" Width=""75"" Height=""75"" HorizontalAlignment=""Left"">
                        <TextBlock Text=""{Binding Path=Key}"" 
                                               Foreground=""{StaticResource PhoneForegroundBrush}"" 
                                               Style=""{StaticResource PhoneTextExtraLargeStyle}""
                                               VerticalAlignment=""Bottom""/>
                    </Border>
                </Border>
            </DataTemplate>";

        this.GroupHeaderTemplate = (DataTemplate)XamlReader.Load(groupHeaderTemplate);

        var itemTemplate = @"
            <DataTemplate xmlns='http://schemas.microsoft.com/client/2007'>
                <TextBlock Text=""{Binding Title}"" FontSize=""30""/>
            </DataTemplate>";

        this.ItemTemplate = (DataTemplate)XamlReader.Load(itemTemplate);
    }
}

然后我将它添加到LongListSelector示例中,与所有其他长列表选择器的枢轴相同：

<controls:PivotItem Header="SLLS">
                <local:SimpleLongListSelector x:Name="simple" />
            </controls:PivotItem>

然后我把它的来源与LoadLinqMovies()中的电影源相同,

simple.ItemsSource = moviesByCategory;

然后运行代码(我知道它看起来不漂亮,这是因为绑定没有设置正确,我这样做,所以你知道这不是数据,如果你愿意,你可以这样做：

simple.ItemsSource = movies.GroupBy((m) => m.Title[0]).Select((c) => new PublicGrouping<char,Movie>(c));

看起来我想要看它.

那么,无论哪种情况,这都是按预期的方式工作,除非我点击组头. (任何[默认蓝色]方块).我得到了

WrappedException

错误信息是：

0xc00cee3c

我认为是什么意思：

well-formedness constraint: unique attribute spec

我不认为我有一个唯一性的问题.我究竟做错了什么？