我试过这个How to: Filter Data in a View所以我尝试了这种方法，但它对我不起作用，因为Windows Phone 8环境找不到'ListCollectionView'。
我的收藏正在关注。
//My observableCollection
ObservableCollection<ClonedWrapper> dsForProgress = new ObservableCollection<ClonedWrapper >();
//My Function which shows at first time.
private async Task CloudImages()
{
IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication();
try
{
List<MainWrapper> serverdata = new List<MainWrappe>();
serverdata = await ImageUrlAsync();//This function is returning the Deserialize object of images
if (serverdata.Count != 0)
{
foreach (var imgInfo in serverdata)
{
string folderPath = "Fagbokforlaget/Books/" + BookInfo.Id.Trim();
ClonedWrapper item = new ClonedWrapper()
{
//Name, Cover, Info, Title, IsEnableButton, IsVisibleButton,
// IsVisible are the assigned keys to the xaml page
Id = imgInfo.Id,
Name = imgInfo.Name,
Cover = await GetCoverImage(imgInfo),
Info = imgInfo.Info,
Title = imgInfo.Title,
Url = imgInfo.Url,
IsEnableButton = "True",
IsVisible = "Collapsed",
Date = Convert.ToDateTime(imgInfo.Date)
};
if (isf.DirectoryExists(folderPath))
{
item.ButtonStatus = "Read";
item.IsVisibleBookDeleteButton = "Visible";
}
else
{
item.ButtonStatus = "Download";
item.IsVisibleBookDeleteButton = "Collapsed";
}
dsForProgress.Add(item);
}
}
else
{
MessageBox.Show("You have no any downloaded books!");
}
listCloudImages.ItemsSource = dsForProgress;
}
catch (Exception exe)//I am getting exception here on extreme first run in absense of internet.
{
MessageBox.Show(exe.Message);
}
}
//我的xaml页面如下。它是第一次加载的默认页面。你可以说它是应用程序的面孔。用户下载图像。和buttonStatus转换为Read按钮。所以现在我正在做什么我会在appliationbar中保留两个按钮，一个云下载第二个。在下载按钮单击我想只显示下载的图像。
<ListBox Name="listCloudImages" Visibility="Visible" Grid.Row="1" ScrollViewer.VerticalScrollBarVisibility="Auto" FontFamily="Segoe UI" FontStyle="Normal" FontWeight="Thin" Margin="0,0,0,50">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<tools:WrapPanel Orientation="Horizontal">
</tools:WrapPanel>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Setter Property="HorizontalContentAlignment" Value="Stretch"></Setter>
</Style>
</ListBox.ItemContainerStyle>
<ListBox.ItemTemplate>
<DataTemplate>
<Border BorderThickness="1" Background="#151414" CornerRadius="3" Margin="3" Width="150" TextOptions.DisplayColorEmoji="True" BorderBrush="#1c1b1b">
<StackPanel Orientation="Vertical">
<StackPanel Orientation="Horizontal">
<Image x:Name="imgBookImage" Source="{Binding Cover}" Visibility="Visible" VerticalAlignment="Top" HorizontalAlignment="Center"
Width="80" Height="100" ImageOpened="imgBookImage_ImageOpened"/>
<StackPanel Orientation="Horizontal">
<TextBlock Visibility="{Binding IsVisible}" Text="{Binding ProgressPercentage}" FontFamily="Segoe UI" FontSize="18" FontWeight="ExtraBold" Foreground="White" Margin="5,0"></TextBlock>
</StackPanel>
</StackPanel>
<StackPanel Orientation="Vertical">
<TextBlock Text="{Binding Title}" FontFamily="Segoe UI" FontSize="13.5"
Foreground="White" TextTrimming="WordEllipsis"
VerticalAlignment="Top" HorizontalAlignment="Left"
TextWrapping="Wrap"
Width="300" Padding="2"/>
<TextBlock Text="{Binding Info}" FontSize="13.5" FontFamily="Segoe UI"
Foreground="White"
VerticalAlignment="Top" HorizontalAlignment="Left"
TextWrapping="Wrap"
Width="300" Padding="2"/>
<ProgressBar x:Name="downloadProgressBar" Foreground="Green" IsIndeterminate="True" VerticalAlignment="Center" Width="120" TextOptions.TextHintingMode="Animated" Visibility="{Binding IsVisible}" CharacterSpacing="2"/>
<Button Content="{Binding ButtonStatus}" x:Name="btnDownload" IsEnabled="{Binding IsEnableButton, Converter={StaticResource ButtonVisibilityIsEnableConverter}}"
Click="btnDownload_Click" Tag="{Binding}" Width="120" BorderThickness="1" FontSize="13.5" Margin="0,5"
FontFamily="Segoe UI" tools:SlideInEffect.LineIndex="2" HorizontalAlignment="Left" VerticalAlignment="Top"
Foreground="White">
</Button>
<Image x:Name="imgCancelImage" Source="/Assets/Tiles/CancelImage.png" Visibility="{Binding IsVisible}" VerticalAlignment="Center" Margin="97,-66,0,0"
Tap="imgCancelImage_Tap" HorizontalAlignment="Right" Width="25" Height="25" Tag="{Binding}"/>
<Button x:Name="btnDeleteImage" Click="btnDeleteImage_Click"
Tag="{Binding}" BorderThickness="1" Margin="97,-66,0,0"
Height="55" Width="55"
Visibility="{Binding ButtonStatus, Converter={StaticResource DeleteButtonVisibilityConverter}}">
<Button.Background>
<ImageBrush ImageSource="/Images/delete.png" Stretch="Fill"></ImageBrush>
</Button.Background>
</Button>
</StackPanel>
</StackPanel>
</Border>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
答案 0 :(得分：1)
在您的图书模型中，您可以传递bool属性IsDownload，当您下载图书时，您将此属性设置为true。对于您的过滤器，只需使用linQ获取所有图书下载或没有这样的下载：
var noDownloadedBooks =
from b in yourObservableCollection
where b.IsDownload == false
select b;
var downloadedBooks =
from b in yourObservableCollection
where b.IsDownload == true
select b;
答案 1 :(得分：1)
根据您的代码，您可以轻松地做一些事情，如果您只想显示已下载的书籍，请尝试以下方法：
private void ApplicationBarButtonShowAllDownLoaded(object sender, EventArgs e)
{
var c = (Application.Current as App).dsForProgress.Where(x => x.ButtonStatus.Equals("Download"));
listCloudImages.ItemsSource = c;
}
确保ObservableCollection<ClonedWrapper> dsForProgress是公开的
答案 2 :(得分：0)
您需要做的是使用CollectionViewSource，它可以指向您的原始集合，它可以处理过滤！ Scott Hanselman在这里有一个很好的博客文章示例... http://www.hanselman.com/blog/CollectionViewSourceIsCrazyUsefulForBindingToFilteredObservableCollectionsOnWindowsPhone8.aspx