无法清除 ListBox.SelectedItems 集合 wpf

can't clear ListBox.SelectedItems collection wpf

提问by MasterMedia

I can't clear ListBox.SelectedItems collection. Please suggest what I'm doing wrong. I clear collection in different ways, but it leave previous collection.

我无法清除 ListBox.SelectedItems 集合。请建议我做错了什么。我用不同的方式清除收藏，但它离开以前的收藏。

I clear collection so:

我清除收集所以：

chListBox.SelectedItems.Clear();

or

或者

chListBox.UnselectAll();

or

或者

chListBox.SetSelectedItems(new ArrayList());

My code:

我的代码：

public class CheckListBox : ListBox
    {
        public CheckListBox()
        {
            this.SelectionChanged += CheckListBox_SelectionChanged;
            this.Resources = Application.LoadComponent(new Uri("/TASWpfControls;component/Resources/CheckListBoxResources.xaml", UriKind.RelativeOrAbsolute)) as ResourceDictionary;
            this.ItemContainerStyle = this.Resources["CheckListBoxItem"] as Style;
            this.AddHandler(ButtonBase.ClickEvent, new RoutedEventHandler(ClickEventHandler));
        }

        private void ClickEventHandler(object sender, RoutedEventArgs routedEventArgs)
        {
            RoutedEventArgs eventArgs = new RoutedEventArgs(ItemSelectedEvent);
            this.RaiseEvent(eventArgs);
        }

        public string PropertyName { get; set; }

        public string PropertyCompare { get; set; }

        public static readonly DependencyProperty SelectedSourceProperty =
            DependencyProperty.Register("SelectedSource", typeof(IList), typeof(CheckListBox), new PropertyMetadata(SelectedSourceChanged));

        public IList SelectedSource
        {
            get { return (IList)GetValue(SelectedSourceProperty); }
            set { SetValue(SelectedSourceProperty, value); }
        }

        public static RoutedEvent ItemSelectedEvent =
            EventManager.RegisterRoutedEvent("ItemSelected", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(CheckListBox));

        public event RoutedEventHandler ItemSelected
        {
            add { AddHandler(ItemSelectedEvent, value); }
            remove { RemoveHandler(ItemSelectedEvent, value); }
        }

        protected static void SelectedSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            CheckListBox chListBox = d as CheckListBox;
            if (chListBox != null)
                chListBox.SortListBox(chListBox, e.NewValue);
        }

        protected virtual void SortListBox(CheckListBox chListBox, object newValue)
        {
            chListBox.SelectedSource = newValue as IList;
            IList selectedItems = chListBox.SelectedSource;
            chListBox.SelectedItems.Clear();
            if (selectedItems != null && selectedItems.Count > 0)
            {
                foreach (object selectedItem in selectedItems)
                {
                    foreach (object item in chListBox.Items)
                    {
                        if (eIReflector.GetValue(item, chListBox.PropertyName).Equals(eIReflector.GetValue(selectedItem, chListBox.PropertyName)))
                            chListBox.SelectedItems.Add(item);
                    }
                }
            }
        }

        protected virtual void CheckListBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            foreach (object addedItem in e.AddedItems)
            {
                if (!SelectedItems.Contains(addedItem))
                    SelectedItems.Add(addedItem);

                if (!SelectedSource.Contains(addedItem))
                    SelectedSource.Add(addedItem);
            }

            foreach (object removedItem in e.RemovedItems)
            {
                this.SelectedItems.Add(removedItem);
                this.SelectedSource.Remove(removedItem);
            }
        }
    }

回答by Microsoft DN

Try using

尝试使用

chListBox.ClearSelection(); // For C#

and

和

chListBox.UnselectAll(); // For WPF

It is working perfect for me...

它对我来说非常完美......

回答by WillB3

I was able to do it in WPF doing the following:

我能够在 WPF 中执行以下操作：

while(chListBox.SelectedItems.Count > 0)
{
     chListBox.Items.Remove(chListBox.SelectedItem);
}

回答by RJ Thompson

I was able to get it working with the following:

我能够使用以下方法使其工作：

    var listboxItem = m_listBoxAutocomplete.FindChildElements<ListBoxItem>().FirstOrDefault(t => t.IsSelected);
    Keyboard.Focus(listboxItem);

However you will need to google FindChildElements extention which is readily available

但是，您需要谷歌 FindChildElements 扩展，这是现成的