Es scheint nicht möglich zu sein, die SelectedItems-Auflistung einer datengebundenen WPF-ListBox zu löschen. Ich habe versucht, ListBox.SelectedItems.Clear () aufzurufen. Ich habe versucht, SelectedIndex auf -1, SelectedItem auf null und ListBox.UnselectAll () aufzurufen. Während des Debuggens scheint es, dass entweder die Zuweisungen nicht übernommen werden oder die SelectedItems-Auflistung zurückgesetzt wird, aber ich weiß nicht, was. Ich habe einen Haltepunkt in den SelectionChanged-Rückruf eingefügt und dieser wird nie unerwartet getroffen, obwohl das SelectedItems.Count-Mitglied immer mindestens 1 ist (manchmal mehr als 1, da der Auswahlmodus dieser ListBox MultiExtended ist).

Hat das schon mal jemand gesehen und weiß, was ich falsch mache? Diese Frage ist anscheinend genau die gleiche wie diese:WPF - Wie lösche ich die Auswahl in ListView?

Außer in diesem Beitrag verwendet Sonny Boy eine ListView und ich verwende eine ListBox. In jedem Fall war die Antwort, über die abgestimmt wurde, der Aufruf von ListView.UnselectAll (), was in meinem Fall nicht funktioniert.

Ich habe das Gefühl, dass ich offensichtlich etwas falsch machen muss, da das Löschen der Auswahl ziemlich einfach sein sollte.

ANMERKUNG: Nur um klar zu sein, ich möchte die Auswahl nicht aus der ListBox entfernen, ich möchte nur, dass nichts ausgewählt wird.

Vielen Dank!

                            <ListBox Background="{StaticResource ResourceKey=DarkGray}" Name="lbx_subimageThumbnails" Margin="6,6,6,0" ItemsSource="{Binding ElementName=lbx_thumbnails, Path=SelectedItem.Swatches}" Style="{StaticResource WPTemplate}" SelectionMode="Extended" Height="{Binding ElementName=sld_swatchRows, Path=Value}" VerticalAlignment="Top" SelectionChanged="lbx_subimageThumbnails_SelectionChanged" DataContext="{Binding}">
                            <ListBox.ItemsPanel>
                                <ItemsPanelTemplate>
                                    <WrapPanel HorizontalAlignment="Stretch" />
                                </ItemsPanelTemplate>
                            </ListBox.ItemsPanel>
                            <ListBox.ItemContainerStyle>
                                <Style TargetType="{x:Type ListBoxItem}">
                                    <Setter Property="Visibility" Value="{Binding Path=Vis}" />
                                </Style>
                            </ListBox.ItemContainerStyle>
                            <ListBox.ItemTemplate>
                                <DataTemplate>
                                    <Grid Width="270" Height="270" Margin="5,5,5,5" Tag="{Binding}" Name="lbx_swatchThumbnail" Background="{StaticResource ResourceKey=LightGray}" PreviewMouseLeftButtonDown="lbx_swatchThumbnail_PreviewMouseLeftButtonDown" PreviewMouseMove="lbx_swatchThumbnail_PreviewMouseMove">
                                        <Grid.LayoutTransform>
                                            <ScaleTransform CenterX="0" CenterY="0" ScaleX="0.50" ScaleY="0.50" />
                                        </Grid.LayoutTransform>
                                        <Grid.ContextMenu>
                                            <ContextMenu>
                                                <MenuItem Header="Sync selected" Click="btn_syncSwatch_Click" />
                                                <MenuItem Header="Re-export selected" Click="btn_exportSelected_Click"/>
                                                <MenuItem Header="Set as default thumbnail" Click="btn_setThumbnail_Click"/>
                                                <MenuItem Header="Delete selected" Click="btn_deleteSwatch_Click"/>
                                                <MenuItem Header="Show in Explorer" Click="mnu_showSwatchesInExplorer_Click" />
                                                <MenuItem Header="Create Frames" Click="mnu_createFrames_Click" ToolTip="Creates FRAMEs groups to your PSD file under the Group associated with the selected swatch. DO NOT RE-ORDER OR RENAME THE GENERATED groups!" />
                                                <MenuItem Header="Create MIPs" Click="mnu_createMIPs_Click" ToolTip="Creates MIPs groups to your PSD file under the Group associated with the selected swatch. DO NOT RE-ORDER OR RENAME THE GENERATED groups!" />
                                            </ContextMenu>
                                        </Grid.ContextMenu>
                                        <Border BorderBrush="Black" BorderThickness="1">
                                            <Grid ToolTip="{Binding Path=Texture}">
                                                <Image VerticalAlignment="Center" HorizontalAlignment="Center" PhotoLoader:Loader.DisplayOption="Preview" PhotoLoader:Loader.DisplayWaitingAnimationDuringLoading="True" PhotoLoader:Loader.Source="{Binding Path=Texture}" PhotoLoader:Loader.DisplayErrorThumbnailOnError="True" Width="256" Height="256" />
                                                <TextBlock VerticalAlignment="Top" HorizontalAlignment="Center" Margin="0,10,0,0" FontSize="20"  Text="{Binding Path=Group}" Background="Black" Foreground="White"/>
                                                <TextBlock VerticalAlignment="Bottom"  HorizontalAlignment="Center" Background="Black" Margin="0,0,0,10" FontSize="20" Foreground="White">
                                                    <TextBlock.Text>
                                                        <MultiBinding StringFormat="{}{0} x {1} {2}" >
                                                            <Binding Path="Width" />
                                                            <Binding Path="Height" />
                                                            <Binding Path="Format" />
                                                        </MultiBinding>
                                                    </TextBlock.Text>
                                                </TextBlock>
                                            </Grid>
                                        </Border>
                                    </Grid>
                                </DataTemplate>
                            </ListBox.ItemTemplate>
                        </ListBox>

        // this callback kicks everything off. 
        private void btn_editSwatch_Click(object sender, RoutedEventArgs e)
        {
            // get a list of the selected indices - we will have to unselect the texture source and reselect it after the re-export in order to force the thumbnail display to update
            // so we will save a list of indices to reselect them after the export
            List selectedIndices = new List();
            for (int i = 0; i < lbx_subimageThumbnails.Items.Count; i++)
            {
                if (lbx_subimageThumbnails.SelectedItems.Contains(lbx_subimageThumbnails.Items[i]))
                {
                    selectedIndices.Add(i);
                }
            }<p></p>

<pre><code>        // store the index of the selected texture source to reselect it after the re-export
        int selIndex = lbx_thumbnails.SelectedIndex;

        // edit and re-export the selected thumbnails
        if (this.EditThumbnails(lbx_subimageThumbnails.SelectedItems, lbx_thumbnails.SelectedItem))
        {

            // re-select the texture source
            lbx_thumbnails.SelectedIndex = selIndex;

            // re-select the previously selected thumbnails.
            foreach (int index in selectedIndices)
            {
                if (!lbx_subimageThumbnails.SelectedItems.Contains(lbx_subimageThumbnails.Items[index]))
                {
                    lbx_subimageThumbnails.SelectedItems.Add(lbx_subimageThumbnails.Items[index]);
                }
            }
        }
    }

    private void lbx_subimageThumbnails_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        ListBox textureSelector = sender as ListBox;
        if (textureSelector != null)
        {
            //update some UI elements
        }
    }

    /*
    this is the SelectionChanged callback for another listbox which is bound as the ItemSource of lbx_subimageThumbnails. When the selection here changes, we default the selection of the subimage listbox to the first subimage after first clearing the selected items in the subimage listbox
    */
    private void lbx_thumbnails_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        // clear the previous swatch selection and select the first thumbnail
        // None of these methods works. after each, lbx_subimageThumbnails.SelectedItems.Count is still >= 1
        // Also, trying to set the SelectedIndex doesn't take. After the assignment, debugger shows                          
        // SelectedIndex is still 0 
        lbx_subimageThumbnails.SelectedIndex = -1;
        lbx_subimageThumbnails.SelectedIndex = -1;

        // Trying to set SelectedItem to null doesn't work...after assignment, SelectedItem is still a vaild
        // reference
        this.lbx_subimageThumbnails.SelectedItem = null;
        if (lbx_subimageThumbnails.SelectedItems.Count > 0)
        {
            lbx_subimageThumbnails.UnselectAll();
            lbx_subimageThumbnails.SelectedItems.Clear();
        }

        lbx_subimageThumbnails.SelectedIndex = 0;

        // reset the preview pane size
        sld_previewSize.Value = 1.0;
    }
</code></pre>