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C# 筛选的组合框项资源绑定问题_C#_Wpf_Xaml_Binding - Fatal编程技术网

C# 筛选的组合框项资源绑定问题

C# 筛选的组合框项资源绑定问题,c#,wpf,xaml,binding,C#,Wpf,Xaml,Binding,我想做的是: 我有两个组合框,一个普通的,一个可过滤的。在可过滤组合框上,ItemsSource绑定到第一个组合框SelectedItem的属性。 下面是一些XAML来演示我删除的一些属性之间的关系: <ComboBox Name="cbx_poche" ItemsSource="{Binding DataContext.ListePoches, ElementName=Main}" SelectedItem="{Binding PocheCible}" /> <control

我想做的是: 我有两个组合框,一个普通的,一个可过滤的。在可过滤组合框上,ItemsSource绑定到第一个组合框SelectedItem的属性。 下面是一些XAML来演示我删除的一些属性之间的关系:

<ComboBox Name="cbx_poche" ItemsSource="{Binding DataContext.ListePoches, ElementName=Main}" SelectedItem="{Binding PocheCible}" />
<controls:FilteredComboBox ItemsSource="{Binding SelectedItem.SupportsEligibles, ElementName=cbx_poche}" SelectedItem="{Binding Support}" />
代码2: 所以我天真的想法是从绑定视图中获取局部视图。我可以很好地进行过滤,但是在第一次组合中更改所选项目不会在第一次传递后更新列表

protected override void OnItemsSourceChanged(IEnumerable oldValue, IEnumerable newValue)
{
    if (newValue != null && newValue != ItemsSourceView)
    {
        if (ItemsSourceView != null)
            ItemsSourceView.Filter -= this.FilterPredicate;

        ItemsCollectionViewSource = new CollectionViewSource { Source = newValue };
        ItemsSourceView = ItemsCollectionViewSource.View;
        ItemsSourceView.Filter += this.FilterPredicate;
        this.ItemsSource = ItemsSourceView; // Breaks the binding !!
    }

    base.OnItemsSourceChanged(oldValue, newValue);
}
我被困在这里了。
我正在寻找一些事件或绑定类,可以用来通知绑定更改,以便更新视图。或者在不更改项目资源的情况下应用视图我最终使用了一个相当蹩脚的解决方法,因此我仍然对智能答案感兴趣

对于感兴趣的人:我添加了另一个类似的ItemsSource2依赖属性,但仍然没有找到一个好的名称,我将项目列表绑定到该属性上,而不是原始的ItemsSource

更改此items源时,控件将获得一个新的CollectionView(而不是默认的CollectionView),并将其设置为标准ItemsSource。 控件的其他元素与链接文章中的代码保持相同

public static readonly DependencyProperty ItemsSource2Property =
   DependencyProperty.Register(
   "ItemsSource2",
   typeof(IEnumerable),
   typeof(FilteredComboBox),
   new UIPropertyMetadata((IEnumerable)null, new PropertyChangedCallback(OnItemsSource2Changed)));

[Bindable(true)]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
public IEnumerable ItemsSource2
{
    get { return (IEnumerable)GetValue(ItemsSource2Property); }
    set
    {
        if (value == null)
        {
            ClearValue(ItemsSource2Property);
        }
        else
        {
            SetValue(ItemsSource2Property, value);
        }
    }
}

private static void OnItemsSource2Changed(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
    var ic = (FilteredComboBox)d;
    var oldValue = (IEnumerable)e.OldValue;
    var newValue = (IEnumerable)e.NewValue;

    if (newValue != null)
    {
        //Prevents the control to select the first item automatically
        ic.IsSynchronizedWithCurrentItem = false;

        var viewSource = new CollectionViewSource { Source = newValue };
        ic.ItemsSource = viewSource.View;
    }
    else
    {
        ic.ItemsSource = null;
    }
}
public static readonly DependencyProperty ItemsSource2Property =
   DependencyProperty.Register(
   "ItemsSource2",
   typeof(IEnumerable),
   typeof(FilteredComboBox),
   new UIPropertyMetadata((IEnumerable)null, new PropertyChangedCallback(OnItemsSource2Changed)));

[Bindable(true)]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
public IEnumerable ItemsSource2
{
    get { return (IEnumerable)GetValue(ItemsSource2Property); }
    set
    {
        if (value == null)
        {
            ClearValue(ItemsSource2Property);
        }
        else
        {
            SetValue(ItemsSource2Property, value);
        }
    }
}

private static void OnItemsSource2Changed(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
    var ic = (FilteredComboBox)d;
    var oldValue = (IEnumerable)e.OldValue;
    var newValue = (IEnumerable)e.NewValue;

    if (newValue != null)
    {
        //Prevents the control to select the first item automatically
        ic.IsSynchronizedWithCurrentItem = false;

        var viewSource = new CollectionViewSource { Source = newValue };
        ic.ItemsSource = viewSource.View;
    }
    else
    {
        ic.ItemsSource = null;
    }
}