问 WPF自定义控件依赖属性中未知对象的双向绑定问题

EN

我有一个为AutoComplete TextBox实现的自定义控件。我从下面的问题 Create a Custom Control with the combination of multiple controls in WPF C# 中得到了所有的想法。在那个自定义控件中，他们建议使用以下代码来添加项， 它的完美工作和双向绑定太 。

(this.ItemsSource as IList<string>).Add(this._textBox.Text);

但是，我将下面的代码更改为未知对象，因此我将 IList<string> 更改为 IList<object>

(this.ItemsSource as IList<object>).Add(item);

XAML：

 <local:BTextBox 
            ItemsSource="{Binding Collection}" 
            ProviderCommand="{Binding AutoBTextCommand}" 
            AutoItemsSource="{Binding SuggCollection}" />

但是它没有更新 Collection .的ViewModel属性我也尝试过在xaml中进行以下更改

ItemsSource="{Binding Collection, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"

我不知道我在哪里犯的错。

Functionality ：-- CustomControl 内部的 TextBox 从用户那里获取输入，它触发命令根据用户输入过滤远程数据的 ProviderCommand ，，并通过 AutoItemsSource ，发送过滤的集合--该属性被绑定为 CustomControl 中的 ListBox 的 ItemsSource 以选择项。我们可以从 AddCommand 项中选择项，通过单击该项，它将触发位于 CustomControl 类中的命令 CustomControl ，它在 CustomControl 的 ItemSource 属性中添加所选的项。我在这个属性 ItemsSource .中有 双向绑定问题 从这个属性中，我们可以获得所选的项作为集合。

这是 我的完整源代码

自定义控件C#代码：

public class BTextBox : ItemsControl
    static BTextBox()
        DefaultStyleKeyProperty.OverrideMetadata(typeof(BTextBox), new FrameworkPropertyMetadata(typeof(BTextBox)));
    #region Private Members
    private TextBox _textBox;
    private ItemsControl _itemsView;
    #endregion
    #region Dependency Property Private Members
    public static readonly DependencyProperty ProviderCommandProperty = DependencyProperty.Register("ProviderCommand", typeof(ICommand), typeof(BTextBox), new PropertyMetadata(null));
    public static readonly DependencyProperty AutoItemsSourceProperty = DependencyProperty.Register("AutoItemsSource", typeof(IEnumerable<dynamic>), typeof(BTextBox), new PropertyMetadata(null, OnItemsSourceChanged));
    #endregion
    #region Dependency Property Public members
    public IEnumerable<dynamic> AutoItemsSource
        get { return (IEnumerable<dynamic>)GetValue(AutoItemsSourceProperty); }
        set { SetValue(AutoItemsSourceProperty, value); }
    #endregion
    #region Listener Methods
    private static void OnItemsSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        var tb = d as BTextBox;
        if ((e.NewValue != null) && ((tb.ItemsSource as IList<object>) != null))
            (tb.AutoItemsSource as IList<object>).Add(e.NewValue);
    #endregion
    #region Override Methods
    public override void OnApplyTemplate()
        this._textBox = this.GetTemplateChild("PART_TextBox") as TextBox;
        this._itemsView = this.GetTemplateChild("PART_ListBox") as ItemsControl;
        this._textBox.TextChanged += (sender, args) =>
            if (this.ProviderCommand != null)
                this.ProviderCommand.Execute(this._textBox.Text);
        base.OnApplyTemplate();
    #endregion
    #region Command
    public ICommand ProviderCommand
        get { return (ICommand)GetValue(ProviderCommandProperty); }
        set { SetValue(ProviderCommandProperty, value); }
    public ICommand AddCommand
            return new DelegatingCommand((obj) =>
                (this.ItemsSource as IList<object>).Add(obj);
    #endregion
}

Generic.xaml 代码是

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:SampleControl">
    <Style TargetType="{x:Type local:BTextBox}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type local:BTextBox}">
                    <Border Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}">
                            <Grid.RowDefinitions>
                                <RowDefinition Height="40"/>
                                <RowDefinition Height="Auto"/>
                            </Grid.RowDefinitions>
                            <TextBox x:Name="PART_TextBox" Grid.Row="0" Width="*" VerticalAlignment="Center" />
                            <ListBox ItemsSource="{TemplateBinding AutoItemsSource}" Grid.Row="1" x:Name="PART_ListBox_Sugg" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                                <ListBox.ItemTemplate>
                                    <DataTemplate>
                                        <CheckBox IsChecked="{Binding Value.IsChecked}" Command="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:BTextBox}}, Path=AddCommand}" CommandParameter="{Binding }" Foreground="#404040">
                                            <CheckBox.Content>
                                                <StackPanel Orientation="Horizontal">
                                                    <TextBlock Text="{Binding }" Visibility="Visible"  TextWrapping="Wrap" MaxWidth="270"/>
                                                </StackPanel>
                                            </CheckBox.Content>
                                        </CheckBox>
                                    </DataTemplate>
                                </ListBox.ItemTemplate>
                            </ListBox>
                        </Grid>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>

MainWindow.xaml 代码是

<Window x:Class="SampleControl.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:SampleControl" 
        Title="MainWindow" Height="400" Width="525">
        <local:BTextBox 
            ItemsSource="{Binding Collection}" 
            ProviderCommand="{Binding AutoBTextCommand}" 
            AutoItemsSource="{Binding SuggCollection}" />
    </Grid>
</Window>

代码 背后的MainWindow.xaml代码

public partial class MainWindow : Window
    public MainWindow()
        InitializeComponent();
        this.DataContext = new StringModel();
}

我有两个ViewModels

StringModel ViewModel #1

class StringModel : INotifyPropertyChanged
    public event PropertyChangedEventHandler PropertyChanged;
    private ObservableCollection<string> _collection = new ObservableCollection<string>();
    private ObservableCollection<string> _suggCollection = new ObservableCollection<string>();
    private ObservableCollection<string> _primaryCollection = new ObservableCollection<string>();
    public ObservableCollection<string> Collection
        get { return _collection; }
            _collection = value;
            if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Collection"));
    public ObservableCollection<string> SuggCollection
        get { return _suggCollection; }
            _suggCollection = value;
            if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("SuggCollection"));
    public StringModel()
        _primaryCollection = new ObservableCollection<string> { 
            "John", "Jack", "James", "Emma", "Peter"
    public ICommand AutoBTextCommand
            return new DelegatingCommand((obj) =>
                Search(obj as string);
    private void Search(string str)
        SuggCollection = new ObservableCollection<string>(_primaryCollection.Where(m => m.ToLowerInvariant().Contains(str.ToLowerInvariant())).Select(m => m));
}

IntModel ViewModel #2

class IntModel : INotifyPropertyChanged
    public event PropertyChangedEventHandler PropertyChanged;
    private ObservableCollection<int> _collection = new ObservableCollection<int>();
    private ObservableCollection<int> _suggCollection = new ObservableCollection<int>();
    private ObservableCollection<int> _primaryCollection = new ObservableCollection<int>();
    public ObservableCollection<int> Collection
        get { return _collection; }
            _collection = value;
            if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Collection"));
    public ObservableCollection<int> SuggCollection
        get { return _suggCollection; }
            _suggCollection = value;
            if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("SuggCollection"));
    public IntModel()
        _primaryCollection = new ObservableCollection<int> { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
                                                                11, 12, 13, 14, 16, 17, 18, 19, 20 };
    public ICommand AutoBTextCommand
            return new DelegatingCommand((obj) =>
                Search(obj as string);
    private void Search(string str)
        int item = 0;
        int.TryParse(str, out item);
        SuggCollection = new ObservableCollection<int>(_primaryCollection.Where(m => m == item).Select(m => m));
}