WPF ListBoxItem ControlTemplate打破了一些MouseDown/Selection

Question

我有一个问题ListBoxItem.我试图让所有的控制在ListBoxItem选择它作为很好,所以点击一个TextBox,Label等会选择ListBoxItem.到目前为止很简单.

我也在更改ListBoxItem模板以更改选择可视化,从突出显示背景到仅绘制边框.也很简单.

这两者的结合,然而,似乎导致有一些很刺激的问题MouseDown和PreviewMouseDown,特别是在我的情况下,关于LabelS IN一个Grid,其中一个创建一个"空白"所占据Grid的空间.

使用snoop,我可以看到PreviewMouseDown事件在ScrollViewer内部停止ListBox,而不是一直到达ListBoxItem.

XAML:

<Window x:Class="ListBoxClickThroughTest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow"
        Width="525"
        Height="350">
    <Grid>
        <ListBox ItemsSource="{Binding Items}"
                 SelectionMode="Single">

            <ListBox.ItemTemplate>
                <DataTemplate>
                    <Grid>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="Auto" />
                            <ColumnDefinition Width="*" />
                        </Grid.ColumnDefinitions>
                        <Grid.RowDefinitions>
                            <RowDefinition />
                            <RowDefinition />
                        </Grid.RowDefinitions>

                        <Label Name="VerySuperLongLabel"
                               Grid.Row="0"
                               Grid.Column="0"
                               HorizontalAlignment="Left"
                               Content="VerySuperLongLabel"
                               Padding="0" />

                        <TextBox Name="Textbox1"
                                 Grid.Row="0"
                                 Grid.Column="1"
                                 HorizontalAlignment="Stretch"
                                 HorizontalContentAlignment="Right"
                                 Text="Textbox1 Text" />


                        <Label Name="ShortLabel"
                               Grid.Row="1"
                               Grid.Column="0"
                               HorizontalAlignment="Left"
                               Content="ShortLabel"
                               Padding="0" />
                        <TextBox Name="Textbox2"
                                 Grid.Row="1"
                                 Grid.Column="1"
                                 HorizontalAlignment="Stretch"
                                 HorizontalContentAlignment="Right"
                                 Text="Textbox2 Text" />
                    </Grid>
                </DataTemplate>
            </ListBox.ItemTemplate>

            <ListBox.ItemContainerStyle>
                <Style TargetType="{x:Type ListBoxItem}">
                    <EventSetter Event="PreviewMouseDown"
                                 Handler="ListBoxItem_PreviewMouseDown" />
                    <EventSetter Event="MouseDown"
                                 Handler="ListBoxItem_PreviewMouseDown" />
                    <Setter Property="HorizontalContentAlignment" Value="Stretch" />
                    <Setter Property="Template">
                        <Setter.Value>
                            <ControlTemplate TargetType="{x:Type ListBoxItem}">
                                <Border x:Name="Bd"
                                        BorderThickness="1">
                                    <ContentPresenter />
                                </Border>
                                <ControlTemplate.Triggers>
                                    <Trigger Property="IsSelected" Value="true">
                                        <Setter TargetName="Bd" Property="BorderBrush" Value="Gray" />
                                    </Trigger>
                                </ControlTemplate.Triggers>
                            </ControlTemplate>
                        </Setter.Value>
                    </Setter>
                </Style>
            </ListBox.ItemContainerStyle>
        </ListBox>

    </Grid>
</Window>

代码隐藏:

using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace ListBoxClickThroughTest
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            Items = new List<string>() { "1", "2" };
            InitializeComponent();
            DataContext = this;
        }

        public List<string> Items { get; set; }

        private void ListBoxItem_PreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            var listBoxItem = (ListBoxItem)sender;
            listBoxItem.IsSelected = true;
        }
    }
}

但是,如果我删除了Templatesetter,一切都很好.我缺少的模板中是否有一些魔法？我尝试将边框重命名为"Bd",因为这是默认模板边框的名称,但没有运气.有任何想法吗？

Answer 1

如果您将标签的水平对齐方式从"左"更改为"拉伸",这将解决问题并保持视觉格式相同.

Mousedown事件仅适用于存在元素的区域.通过使标签处于"左"水平对齐,您将创建您提到的"空白",其中在该级别上不存在可以单击的元素.要直观地看到差异,请尝试临时设置给您带来问题的标签元素的背景属性,并且您将看到元素不会一直延伸到文本框.