WPF 元素主机每秒崩溃一次

我在Windows表单项目中有一个WPF用户控件，但我遇到了问题。我的应用每次崩溃，因为元素主机无法在用户控件中加载数据。

当我把它放在 WPF 项目中时，也会发生同样的事情。我的应用程序每隔一秒钟就正常启动一次。

知道可能是什么问题吗？这是我的用户控件代码：

<UserControl x:Class="Fleet_management.Info"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             mc:Ignorable="d" Height="492" Width="578">
    <UserControl.Background>
        <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
            <GradientStop Color="#FFE2E2E2" Offset="0" />
            <GradientStop Color="White" Offset="1" />
        </LinearGradientBrush>
    </UserControl.Background>
    <UserControl.Resources>
        <XmlDataProvider x:Key="rssData" XPath="//item" Source="******" />
    </UserControl.Resources>
    <Grid Margin="3" Height="598" Width="565">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="252*" />
            <ColumnDefinition Width="90*" />
            <ColumnDefinition Width="223*" />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="177*" />
            <RowDefinition Height="55*" />
            <RowDefinition Height="122*" />
            <RowDefinition Height="177*" />
        </Grid.RowDefinitions>
        <ListBox x:Name="lstItems" Margin="3,0" ItemsSource="{Binding Source={StaticResource rssData}}"
                 SelectedIndex="0" VerticalAlignment="Stretch" FontStretch="Normal" FontSize="14" FontFamily="Lucida Sans Unicode" Grid.ColumnSpan="3">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal">
                        <Image Width="20" Margin="3" Source="{Binding XPath=enclosure/@url}" />
                        <TextBlock Margin="3" VerticalAlignment="Center" Text="{Binding XPath=title}" FontWeight="Bold" />
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
        <StackPanel Grid.Row="1" Orientation="Vertical" DataContext="{Binding ElementName=lstItems, Path=SelectedItem}" Margin="0,0,0,5" Grid.ColumnSpan="3">
            <TextBlock Margin="3" FontSize="13" FontWeight="Bold" Text="{Binding XPath=title, Path=InnerText}" />
            <TextBlock Margin="3" Opacity="0.72" Text="{Binding XPath=pubDate}" />
        </StackPanel>
        <ScrollViewer CanContentScroll="True" Grid.Row="2" HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto"  DataContext="{Binding ElementName=lstItems, Path=SelectedItem}" Margin="0,0,3,115" Grid.RowSpan="2" Grid.ColumnSpan="3">
            <TextBlock  Margin="3"
                       FontStyle="Italic" Text="{Binding XPath=description, Path=InnerText}" TextWrapping="Wrap" TextAlignment="Justify" AllowDrop="False"
                       Foreground="#FF0000E7" FontFamily="Lucida Sans Unicode" FontSize="14" Padding="0,0,5,0" VerticalAlignment="Center" />
        </ScrollViewer>
    </Grid>
</UserControl>