WPF Learning Notes

8. Collection view when binding to a collection object, WPF always provides a view by default (CollectionViewSource). The view is associated to the source collection and automatically displays the associated action on the target object.

(1) Sorting

Inserting one or more sort criteria (sortdescription) into the Collectionviewsource.sortdescriptions property enables single or multiple conditional sorting.

Window1.xaml

<window x:class= "Learn.WPF.Window1"
Xmlns= "Http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x= "Http://schemas.microsoft.com/winfx/2006/xaml"
Xmlns:my= "CLR-NAMESPACE:LEARN.WPF"
title= "Window1" >
<Window.Resources>
<my:personallist x:key= "Personals" >
<my:personal name= "Tom" age= "sex=" Male "/>"
<my:personal name= "Mary" age= "one" sex= "Female"/>
<my:personal name= "Jack" age= "sex=" Male "/>"
</my:PersonalList>
</Window.Resources>
<Grid>
<stackpanel datacontext= "{StaticResource personals}" >
<listbox x:name= "ListBox1" Itemssource= "{Binding}" >
<ListBox.ItemTemplate>
<DataTemplate>
<stackpanel orientation= "Horizontal" >
<textblock text= "{Binding path=name}"/>
<TextBlock>,</TextBlock>
<textblock text= "{Binding path=age}"/>
<TextBlock>,</TextBlock>
<textblock text= "{Binding path=sex}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
</Grid>
</Window>

Window1.xaml.cs

public　partial　class　Window1　:　Window
{
　　public　Window1()
　　{
　　　　InitializeComponent();
　　　　var　personals　=　this.FindResource("personals");
　　　　var　view　=　CollectionViewSource.GetDefaultView(personals);
　　　　view.SortDescriptions.Add(new　SortDescription("Age",　ListSortDirection.Ascending));
　　}
}

Changes to the collectionviewsource.sortdescriptions will be directly reflected in the interface display.

protected　void　ButtonClick(object　sender,　RoutedEventArgs　e)
{
　　var　personals　=　this.FindResource("personals");
　　var　view　=　CollectionViewSource.GetDefaultView(personals);
　　var　direction　=　sender　==　btnDesc　?　ListSortDirection.Descending　:　ListSortDirection.Ascending;
　　view.SortDescriptions.Clear();
　　view.SortDescriptions.Add(new　SortDescription("Age",　direction));
}