Question

以下是带有按钮的列表框的代码。

我有两个问题：

1）SelectionChanged没有触发我获取所选项目及其值。

2）我的列表框用于选择多个项目，因此当我选择一个项目时，按钮上没有设置背景。

如何解决这些问题？

<ListBox Name="listBox" 
         HorizontalContentAlignment="Stretch" 
         VerticalContentAlignment="Stretch" 
         SelectionChanged="TopicListboxSelectionChanged"
         ScrollViewer.VerticalScrollBarVisibility="Disabled">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <Button Name="AnswerCell" 
                    Width="456"
                    Content="{Binding Path=Value}"
                    Background="#FFF2F4F7"
                    Foreground="Black" 
                    Style="{StaticResource CellStyle}">
                <Button.ContentTemplate>
                    <DataTemplate>
                        <TextBlock 
                                   Style="{StaticResource TextStyle}"
                                   Padding="0,20,0,20"
                                   TextAlignment="Center"
                                   Text="{Binding}"/>
                    </DataTemplate>
                </Button.ContentTemplate>
            </Button>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

修改

这里我的文本块有边框

<ListBox.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Name="AnswerCellBack" Margin="0,0,0,4" Orientation="Horizontal">
                            <Border Name="borderColor" Background="#FFF2F4F7">
                                <TextBlock Name="Answertext"
                                       Width="456"
                                       Padding="10,20,10,20"
                                       TextAlignment="Center"
                                       Text="{Binding Path=AnswerValue}"
                                       Style="{StaticResource AnswerTextStyle}"/>
                            </Border>
                        </StackPanel>
 </DataTemplate>
                </ListBox.ItemTemplate>

问题在这里：

1）如何更改选择项背景颜色，我在XAML中设置了边框背景。

2）如何添加多项选择。

Answer 1

我相信你的问题是你的DataTemplate，它由一个按钮组成。一个按钮将正常处理路由鼠标点击事件，并且不会给列表框一个操作它的机会，因此你没有得到一个选择事件。

尝试将按钮元素更改为边框，然后查看您的事件是否正在触发？

使用附加属性并将选择更改绑定到命令

也可能不是一个坏主意

    public class SelectionChangeCommand : DependencyObject
    {
        public static bool GetIsRegistered(DependencyObject obj)
        {
            return (bool)obj.GetValue(IsRegisteredProperty);
        }

    public static void SetIsRegistered(DependencyObject obj, bool value)
    {
        obj.SetValue(IsRegisteredProperty, value);
    }

    // Using a DependencyProperty as the backing store for IsRegistered.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty IsRegisteredProperty =
        DependencyProperty.RegisterAttached("IsRegistered", typeof(bool), typeof(SelectionChangeCommand), new PropertyMetadata(false, new PropertyChangedCallback(RegisterForCommand)));

    private static void RegisterForCommand(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (d is Selector)
        {
            Selector sel = (Selector)d;
            if ((bool)e.NewValue)
            {
                sel.SelectionChanged += sel_SelectionChanged;
            }
            else
            {
                sel.SelectionChanged -= sel_SelectionChanged;
            }
        }
    }

    static void sel_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (sender is Selector)
        {
            Selector sel = (Selector)sender;
            ICommand command = GetCommand(sel);

            if (command!=null && command.CanExecute(null))
                command.Execute(sel);
        }
    }

    public static ICommand GetCommand(DependencyObject obj)
    {
        return (ICommand)obj.GetValue(CommandProperty);
    }

    public static void SetCommand(DependencyObject obj, ICommand value)
    {
        obj.SetValue(CommandProperty, value);
    }

    // Using a DependencyProperty as the backing store for Command.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty CommandProperty =
        DependencyProperty.RegisterAttached("Command", typeof(ICommand), typeof(SelectionChangeCommand), new PropertyMetadata(null));
}

在引用xmlns之后，您可以使用xaml中的代码，如下所示：

    <ListBox kernelAttached:SelectionChangeCommand.Command="{Binding SelectedLinkCommand}" 
kernelAttached:SelectionChangeCommand.IsRegistered="True" >

ListBox SelectionChanged没有被调用

1 个答案: