[英]Filter Collection in ListBox using value of TextBlock in ItemsControl
我創建了自己的日歷。 我日歷中的每一天都有一個itemsControl,其中包含一個文本塊和一個列表框,該列表框應按日期保存項目。
如何使用ItemsControl中綁定的文本塊中的字符串值過濾集合? 該文本塊與Day類的date屬性綁定。
視圖模型
public ObservableCollection<Day> Days { get; set; }
public ObservableCollection<Scene> SceneList;
private ListCollectionView _sceneCollection;
public ListCollectionView SceneCollection
{
get
{
if (_sceneCollection == null) //important for loading the app
{
_sceneCollection = new ListCollectionView(this.SceneList);
_sceneCollection.IsLiveFiltering = true;
_sceneCollection.Filter = o =>
{
var Scene = o as Scene;
return Scene != null && Scene.Date == ////string of binded TextBlock//;
};
}
return _sceneCollection;
}
set
{
_sceneCollection = value; RaisePropertyChanged();
}
}
模型
public class Day : INotifyPropertyChanged
{
private DateTime date;
public DateTime Date
{
get { return date; }
set
{
date = value;
if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Date"));
}
}
}
XAML
<ItemsControl ItemsSource="{Binding Days}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<UniformGrid Rows="6" Columns="7">
</UniformGrid>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Date , Converter={StaticResource DateConverter}, ConverterParameter=DAY}"/>
<ListBox ItemsSource="{Binding SceneCollection}" dd:DragDrop.IsDragSource="True"
dd:DragDrop.IsDropTarget="True" Height="100">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock>
<Run Text="{Binding Path=SceneNumber}"/>
<Run Text="{Binding Path=SlugLine}"/>
</TextBlock>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
首先,您的ListBox的ItemsSource
綁定將不起作用,因為它的DataContext是Day對象,並且SceneCollection
屬性不在其中,而在ViewModel中。
另外,您不應該在ViewModel中過濾您的集合,因為所有項目都將綁定到它,並且它們將需要不同的過濾器。
在您的情況下,如果要使用過濾器和集合視圖,同時保持基礎集合不變,則只需在“ Day”類中添加“ ICollectionView”屬性,然后每天為SceneCollection分配一個經過過濾的視圖。
模型:
public class Day : INotifyPropertyChanged
{
private DateTime date;
public DateTime Date
{
get { return date; }
set
{
date = value;
if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Date"));
}
}
private ICollectionView scenes;
public ICollectionView Scenes
{
get { return scenes; }
set
{
scenes = value;
if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Scenes"));
}
}
public event PropertyChangedEventHandler PropertyChanged;
}
ViewModel(示例),在您的Days集合初始化中:
private IEnumerable<Day> CreateDaysData()
{
var maxDays = DateTime.DaysInMonth(DateTime.Now.Year, DateTime.Now.Month);
for (int d = 1; d <= maxDays; d++)
{
var day = new Day
{
Date = new DateTime(DateTime.Now.Year, DateTime.Now.Month, d)
};
var viewSource = new CollectionViewSource
{
Source = ScenesCollection
};
viewSource.Filter += new FilterEventHandler((o, e) =>
{
e.Accepted = (e.Item as Scene).Date == day.Date;
});
day.Scenes = viewSource.View;
yield return day;
}
}
最后,您的XAML最終將如下所示:
<ItemsControl ItemsSource="{Binding Days}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<UniformGrid Rows="6" Columns="7">
</UniformGrid>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Date , Converter={StaticResource DateConverter}, ConverterParameter=DAY}"/>
<!-- The ListBox's ItemsSource is bound to the ICollectionView of your Day class -->
<ListBox ItemsSource="{Binding Scenes}" dd:DragDrop.IsDragSource="True"
dd:DragDrop.IsDropTarget="True" Height="100">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock>
<Run Text="{Binding Path=SceneNumber}"/>
<Run Text="{Binding Path=SlugLine}"/>
</TextBlock>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
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