我正在使用WPF AutoCompleteBox并且我工作得很好，但我想做的一件事就是在每个字母输入主TextBox后立即对建议列表进行排序。有谁知道如何做到这一点？我尝试使用带有DefaultView逻辑的ICollectionView属性并添加SortDescriptions但它似乎没有分阶段建议列表。为了确保我的集合视图排序正常工作，我在同一窗口上放置了一个普通的ListBox控件和一个AutoCompleteBox控件，并将两个控件绑定到具有相同集合视图的同一个observable集合，而普通的ListBox控件显示使用SortDescriptions正确排序的项目，但AutoCompleteBox列表没有排序的项目。它按照它们被添加到集合中的顺序存在。
思考？建议？有没有人这样做过？
答案 0 :(得分：2)
我不知道@ user1089031是如何做到的，但这里有适合任何人感兴趣的样本（更新到@ adabyron的评论！）：
<强> ViewModel.cs
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Windows.Data;
namespace WpfApplication12
{
public class Item
{
public string Name { get; set; }
public override string ToString()
{
return Name;
}
}
public class ViewModel: INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged = delegate {};
private readonly ObservableCollection<Item> source;
private readonly ICollectionView items;
private string searchText;
public ViewModel()
{
source = new ObservableCollection<Item>
{
new Item {Name = "111111111 Test abb - (1)"},
new Item {Name = "22222 Test - (2)"},
new Item {Name = "333 Test - (3)"},
new Item {Name = "44444 Test abc - (4)"},
new Item {Name = "555555 Test cde - (5)"},
new Item {Name = "66 Test - bbcd (6)"},
new Item {Name = "7 Test - cd (7)"},
new Item {Name = "Test - ab (8)"},
};
items = new ListCollectionView(source);
}
public ICollectionView Items
{
get { return items; }
}
public IEnumerable<Item> ItemsSorted
{
get
{
return string.IsNullOrEmpty(SearchText)
? source
: (IEnumerable<Item>)source
.OrderBy(item => item.Name.IndexOf(SearchText,
StringComparison.InvariantCultureIgnoreCase));
}
}
public Item Selected { get; set; }
public string SearchText
{
get { return searchText; }
set
{
searchText = value;
PropertyChanged(this,
new PropertyChangedEventArgs("SearchText"));
PropertyChanged(this,
new PropertyChangedEventArgs("ItemsSorted"));
}
}
}
}
<强> MainWindow.xaml ：
<Window x:Class="WpfApplication12.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Input.Toolkit"
xmlns:wpfApplication2="clr-namespace:WpfApplication12"
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
Title="MainWindow" Height="200" Width="500"
DataContext="{DynamicResource viewModel}">
<Window.Resources>
<wpfApplication2:ViewModel x:Key="viewModel" />
<DataTemplate DataType="{x:Type wpfApplication2:Item}">
<TextBlock Text="{Binding Name}" FontFamily="Courier New" />
</DataTemplate>
</Window.Resources>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<controls:AutoCompleteBox
ItemsSource="{Binding ItemsSorted}"
FilterMode="ContainsOrdinal"
SelectedItem="{Binding Selected, Mode=TwoWay}"
MinimumPrefixLength="0"
VerticalAlignment="Top" Margin="5">
<i:Interaction.Behaviors>
<wpfApplication2:SearchTextBindBehavior
BoundSearchText="{Binding SearchText,
Mode=OneWayToSource}" />
</i:Interaction.Behaviors>
</controls:AutoCompleteBox>
<ListBox Grid.Column="1"
ItemsSource="{Binding Items}" Margin="5" />
</Grid>
</Window>
您可能会注意到我向AutoCompleteBox控件添加了一个自定义行为：
<i:Interaction.Behaviors>
<wpfApplication2:SearchTextBindBehavior
BoundSearchText="{Binding SearchText,
Mode=OneWayToSource}" />
</i:Interaction.Behaviors>
这是因为AutoCompleteBox自己的SearchText属性是只读的。所以这是这种行为的代码：
SearchTextBindBehavior.cs （已更新）
using System.Windows;
using System.Windows.Controls;
using System.Windows.Interactivity;
namespace WpfApplication12
{
public class SearchTextBindBehavior : Behavior<AutoCompleteBox>
{
public static readonly DependencyProperty BoundSearchTextProperty =
DependencyProperty.Register("BoundSearchText",
typeof(string), typeof(SearchTextBindBehavior));
public string BoundSearchText
{
get { return (string)GetValue(BoundSearchTextProperty); }
set { SetValue(BoundSearchTextProperty, value); }
}
protected override void OnAttached()
{
base.OnAttached();
AssociatedObject.TextChanged += OnTextChanged;
}
protected override void OnDetaching()
{
base.OnDetaching();
AssociatedObject.TextChanged -= OnTextChanged;
}
private void OnTextChanged(object sender, RoutedEventArgs args)
{
if(AssociatedObject.Text.Length == 0)
{
BoundSearchText = string.Empty;
return;
}
if(AssociatedObject.SearchText ==
AssociatedObject.Text.Substring(0,
AssociatedObject.Text.Length - 1))
{
BoundSearchText = AssociatedObject.Text;
}
}
}
}
注意：要完成所有工作，您需要添加Expression Blend 4 SDK中对 System.Windows.Interactivity.dll 的引用。这就是Behavior<T>及其朋友生活的地方。
如果您已经安装了Expression Blend，那么您已经拥有了所有SDK，并且无需下载任何内容。以防万一 - 在我的机器上，组件位于此处：
C：\ Program Files \ Microsoft SDKs \ Expression \ Blend.NETFramework \ v4.0 \ Libraries \ System.Windows.Interactivity.dll
最后，如果你有充分的理由不添加对这个流行的官方库的引用，可以通过简单的旧附加属性以“旧方式”重新实现这种自定义行为。
希望有所帮助。
答案 1 :(得分：1)
这就是我最终的结果，略微改编了Sevenate的回答，所以如果你想投票，那就去做他的职位。
我使用了一个子类（由于其他原因我已经将AutoCompleteBox子类化了），这允许我创建一个包装依赖项属性来获取只读SearchText（=用户通过键盘输入的内容）到ViewModel - 而不是混合行为，这也是一种非常有效的方式。
问题的关键在于你应该只对SearchText的更改应用动态排序，而不是Text（= AutoCompleteBox中显示的内容，如果在下拉）。 Sevenate提升readonly ItemsSource（ItemsSorted）的PropertyChanged事件的方法是一种很好的，干净的方式来应用排序。
视图模型：
public class Item
{
public string Name { get; set; }
public override string ToString()
{
return Name;
}
}
public class AutoCompleteBoxDynamicSortingVM : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private readonly ObservableCollection<Item> source;
public AutoCompleteBoxDynamicSortingVM()
{
source = new ObservableCollection<Item>
{
new Item {Name = "111111111 Test abb - (1)"},
new Item {Name = "22222 Test - (2)"},
new Item {Name = "333 Test - (3)"},
new Item {Name = "44444 Test abc - (4)"},
new Item {Name = "555555 Test cde - (5)"},
new Item {Name = "66 Test - bbcd (6)"},
new Item {Name = "7 Test - cd (7)"},
new Item {Name = "Test - ab (8)"},
};
}
public IEnumerable<Item> ItemsSorted
{
get
{
return string.IsNullOrEmpty(Text) ? (IEnumerable<Item>)source :
source.OrderBy(item => item.Name.IndexOf(Text, StringComparison.OrdinalIgnoreCase));
}
}
public Item Selected { get; set; }
// Text that is shown in AutoCompleteBox
private string text;
public string Text
{
get { return text; }
set { text = value; OnPropertyChanged("Text"); }
}
// Text that was entered by user (cannot be changed from viewmodel)
private string searchText;
public string SearchText
{
get { return searchText; }
set
{
searchText = value;
OnPropertyChanged("SearchText");
OnPropertyChanged("ItemsSorted");
}
}
private void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
AutoCompleteBox的子类：
public class MyAutoCompleteBox : AutoCompleteBox
{
/// <summary>
/// Bindable property that encapsulates the readonly property SearchText.
/// When the viewmodel tries to set SearchText by way of EnteredText, it will fail without an exception.
/// </summary>
public string EnteredText
{
get { return (string)GetValue(EnteredTextProperty); }
set { SetValue(EnteredTextProperty, value); }
}
public static readonly DependencyProperty EnteredTextProperty = DependencyProperty.Register("EnteredText", typeof(string), typeof(MyAutoCompleteBox), new PropertyMetadata(null));
protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)
{
// synchronize SearchText and EnteredText (only one-way)
if (e.Property == AutoCompleteBox.SearchTextProperty && this.EnteredText != this.SearchText)
EnteredText = SearchText;
base.OnPropertyChanged(e);
}
}
的Xaml：
<UserControl x:Class="WpfApplication1.Controls.AutoCompleteBoxDynamicSorting"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:myctrls="clr-namespace:WpfApplication1.Controls"
xmlns:models="clr-namespace:WpfApplication1.ViewModels"
Height="350" Width="525"
DataContext="{DynamicResource viewModel}">
<UserControl.Resources>
<models:AutoCompleteBoxDynamicSortingVM x:Key="viewModel" />
<DataTemplate DataType="{x:Type models:Item}">
<TextBlock Text="{Binding Path=Name}" />
</DataTemplate>
</UserControl.Resources>
<Grid>
<myctrls:MyAutoCompleteBox
ItemsSource="{Binding ItemsSorted}"
Text="{Binding Text, Mode=TwoWay}"
EnteredText="{Binding SearchText, Mode=OneWayToSource}"
FilterMode="ContainsOrdinal"
VerticalAlignment="Top" Margin="5" />
</Grid>
</UserControl>