Windows phone 8 如何在Windows Phone 8中筛选可观察的集合？
我尝试了这个方法，所以我尝试了这个方法，但它不适合我，因为windows phone 8环境找不到“ListCollectionView” 我的收藏如下Windows phone 8 如何在Windows Phone 8中筛选可观察的集合？,windows-phone-8,filter,listbox,collectionview,listcollectionview,Windows Phone 8,Filter,Listbox,Collectionview,Listcollectionview,我尝试了这个方法，所以我尝试了这个方法，但它不适合我，因为windows phone 8环境找不到“ListCollectionView” 我的收藏如下 //My observableCollection ObservableCollection<ClonedWrapper> dsForProgress = new ObservableCollection<ClonedWrapper >(); //My Function which shows at first tim
//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observableCollection
ObservableCollection dsForProgress=新的ObservableCollection（）；
//第一次显示的我的函数。
私有异步任务CloudImages（）
{
IsolatedStorageFile isf=IsolatedStorageFile.GetUserStoreForApplication（）；
尝试
{
List serverdata=new List（）；
serverdata=Wait ImageUrlAsync（）；//此函数返回图像的反序列化对象
如果（serverdata.Count！=0）
{
foreach（serverdata中的var imgInfo）
{
字符串folderPath=“Fagbokforlaget/Books/”+BookInfo.Id.Trim（）；
ClonedWrapper项=新ClonedWrapper（）
{
//姓名、封面、信息、标题、IsEnableButton、IsVisibleButton、，
//IsVisible是分配给xaml页面的键
Id=imgInfo.Id，
Name=imgInfo.Name，
封面=等待获取封面图片（imgInfo），
Info=imgInfo.Info，
Title=imgInfo.Title，
Url=imgInfo.Url，
IsEnableButton=“True”，
IsVisible=“折叠”，
日期=Convert.ToDateTime（imgInfo.Date）
};
如果（isf.DirectoryExists（folderPath））
{
item.ButtonStatus=“读取”；
item.IsVisibleBookDeleteButton=“可见”；
}
其他的
{
item.ButtonStatus=“下载”；
item.IsVisibleBookDeleteButton=“折叠”；
}
dsForProgress.Add（项目）；
}
}
其他的
{
Show（“您没有任何下载的书籍！”）；
}
listCloudImages.ItemsSource=dsForProgress；
}
catch（Exception exe）//在没有互联网的情况下，我在极端第一次运行时遇到异常。
{
MessageBox.Show（exe.Message）；
}
}
<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>
在您的图书模型中，您可以传递bool属性IsDownload，当您下载图书时，您可以将此属性设置为true。对于您的筛选器，只需使用linQ进行take all books download或no download，如下所示：
var noDownloadedBooks =
from b in yourObservableCollection
where b.IsDownload == false
select b;
var downloadedBooks =
from b in yourObservableCollection
where b.IsDownload == true
select b;
您需要做的是使用CollectionViewSource，它可以指向您的原始集合，并且可以处理过滤！
Scott Hanselman在这里有一篇很好的博客文章 根据您的代码，您可以做一些非常简单的事情，如果您只想显示下载的书籍，请尝试以下操作：
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
可观察到的收集进度数据