每次我在 TabControl 中切换选项卡时，ListBox Selected Items 都会重置

Question

我有以下 TabControl：

<TabControl Name="tabControl" Grid.Row="0" MinWidth="270" HorizontalAlignment="Stretch" ItemsSource="{Binding Counters}" ContentTemplate="{StaticResource templateForTheContent}"
        ItemTemplate="{StaticResource templateForTheHeader}">
</TabControl>

它使用这个 DataTemplate：

<Window.Resources>

            <DataTemplate x:Key="templateForTheContent" >
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*"/>
                    <ColumnDefinition Width="*"/>
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition Height="1*"/>
                    <RowDefinition  Height="Auto"/>
                </Grid.RowDefinitions>
                <ListBox Grid.Column="0" Grid.ColumnSpan="2" Grid.Row="0" 
                         ItemsSource="{Binding}"
                         SelectionMode="Multiple"
                             BorderThickness="1" BorderBrush="#FF8B8B8B" SelectionChanged="ListBox_SelectionChanged_1">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <TextBlock>
                                <Run Text="{Binding CounterName, Mode=OneWay}" />
                                <Run Text="{Binding InstanceName, Mode=OneWay}" />
                            </TextBlock>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
                <Button Name="RAMSelectAllButton" Margin="0,10,0,0" Grid.Column="0" Grid.Row="1">
                    <TextBlock Text="SELECT ALL"/>
                </Button>
                <Button Name="RAMUnSelectAllButton" Margin="0,10,0,0" Grid.Column="1" Grid.Row="1">
                    <TextBlock Text="UNSELECT ALL"/>
                </Button>
            </Grid>
        </DataTemplate>

            <DataTemplate x:Key="templateForTheHeader" >
                <TextBlock Text="{Binding CategoryName}"/>
            </DataTemplate>

        </Window.Resources>

它按预期工作，绑定工作良好，如果不存在此问题，一切都会很好： 每次我在 TabControl 中切换一个选项卡时，我之前的选项卡中的 ListBox 的选定项目都会被重置 - 所以当我返回该选项卡时 - 没有选择任何内容。

如何解决这个问题？

//编辑 这是我的 ListBox_SelectionChanged_1 方法：

private void ListBox_SelectionChanged_1(object sender, SelectionChangedEventArgs e)
{
    System.Windows.Controls.ListBox listBoxTemp = sender as System.Windows.Controls.ListBox;
    PerformanceCounter counterTemp = (PerformanceCounter)listBoxTemp.Items[0];

    if (!appData.SelectedCounters.ContainsKey(counterTemp.CategoryName))
        appData.SelectedCounters.Add(counterTemp.CategoryName, new List<PerformanceCounter>());

    appData.SelectedCounters[counterTemp.CategoryName].Clear();

    foreach (PerformanceCounter counter in listBoxTemp.SelectedItems)
    {
        appData.SelectedCounters[counterTemp.CategoryName].Add(counter);
    }

}

ListBox 绑定到 Counters，也就是 Observable Collection：

public ObservableCollection<ObservableCollection<PerformanceCounter>> Counters
{
    get { return _Counters; }
}
ObservableCollection<ObservableCollection<PerformanceCounter>> _Counters = new ObservableCollection<ObservableCollection<PerformanceCounter>>();

Answer 1

（我不熟悉 TabControls 或 WPF，但我会建议这样的解决方案：）

在字典中备份列表框的选定项目。

var selectionBackups = new Dictionary<ListBox, IEnumerable<ListBoxItem>>();

我会在ListBox_SelectionChanged_1() 中更新此字段。每当您输入 Tab 时，覆盖相关的ListBox 的选择。

void TabEnter(object sender, TabEventArgs e)
{
    ListBox lb = ... //acquire the current Listbox
    OverwriteSelection(lb, selectionBackups[lb]); //set the ListBox's selection
}

（您可能希望在恢复选择时阻止ListBox_SelectionChanged_1() 触发。可以这样做：

bool auto_select = false; //set this to true while editing selections
private void ListBox_SelectionChanged_1(object sender, SelectionChangedEventArgs e)
{
    if(auto_select)
        return;
    ...
}

)