ListView 绑定的是一个图片的数组 WarehousingImagesList。清除绑定，即从 WarehousingImagesList 中清除对应的元素。 UI 上相应的图片消失。
问题：如何让 BitmapImage 或者说让 ListView 释放这个文件？
<ListView Name="WarehousingImagesView" Grid.Row="1" Visibility="Visible">
<ListView.View>
<l:ImageView/>
</ListView.View>
<ListView.ItemsSource>
<Binding Path="WarehousingImagesList"/>
</ListView.ItemsSource>
</ListView>
<DataTemplate>
<Border>
<Grid>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<Image Grid.Row="0" Margin="3" Height="200">
<Image.Source>
<BitmapImage DecodePixelHeight="200" UriSource="{Binding Path=Photo}">
</BitmapImage>
</Image.Source>
</Image>
<TextBlock Grid.Row="1" Text="{Binding Path=Name}"/>
</Grid>
</Border>
</DataTemplate>
