编号列表框

Question

我有一个排序的列表框，需要显示每个项目的行号。在这个演示中，我有一个带有 Name 字符串属性的 Person 类。列表框显示按名称排序的人员列表。如何将行号添加到列表框的数据模板中？？？

XAML：

<Window x:Class="NumberedListBox.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Height="300" Width="300">
    <ListBox 
        ItemsSource="{Binding Path=PersonsListCollectionView}" 
        HorizontalContentAlignment="Stretch">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <TextBlock Text="{Binding Path=Name}" />
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>
</Window>

后面的代码：

using System;
using System.Collections.ObjectModel;
using System.Windows.Data;
using System.Windows;
using System.ComponentModel;

namespace NumberedListBox
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();

            Persons = new ObservableCollection<Person>();
            Persons.Add(new Person() { Name = "Sally"});
            Persons.Add(new Person() { Name = "Bob" });
            Persons.Add(new Person() { Name = "Joe" });
            Persons.Add(new Person() { Name = "Mary" });

            PersonsListCollectionView = new ListCollectionView(Persons);
            PersonsListCollectionView.SortDescriptions.Add(new SortDescription("Name", ListSortDirection.Ascending));

            DataContext = this;
        }

        public ObservableCollection<Person> Persons { get; private set; }
        public ListCollectionView PersonsListCollectionView { get; private set; }
    }

    public class Person
    {
        public string Name { get; set; }
    }
}

Answer 1

为什么不只绑定到列表框的计数属性。

 <ListView x:Name="LstFocusImageDisplayData"

                          >
                    <ListView.ItemTemplate>
                        <DataTemplate>
                            <GroupBox Header="Item Count">
                                <DockPanel>
                                    <TextBlock Text="{Binding ElementName=LstFocusImageDisplayData, Path=Items.Count, Mode=OneTime}" />
                                </DockPanel>
                            </GroupBox>

                        </DataTemplate>
                    </ListView.ItemTemplate>
                </ListView>

Answer 2

又一个答案。我尝试了上述方法，它适用于 WPF（AlternationCount 解决方案），但我需要 Silverlight 的代码，所以我做了以下操作。这比其他蛮力方法更优雅。

<UserControl xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
  xmlns:local="clr-namespace:RowNumber" x:Name="userControl"
  x:Class="RowNumber.MainPage" Width="640" Height="480">
<Grid x:Name="LayoutRoot" Background="White">
  <ListBox ItemsSource="{Binding Test, ElementName=userControl}">
     <ListBox.Resources>
        <local:ListItemIndexConverter x:Key="IndexConverter" />
     </ListBox.Resources>
     <ListBox.ItemTemplate>
        <DataTemplate>
           <StackPanel Orientation="Horizontal">
              <TextBlock Width="30"
                    Text="{Binding RelativeSource={RelativeSource AncestorType=ListBoxItem}, Converter={StaticResource IndexConverter}}" />
              <TextBlock Text="{Binding}" />
           </StackPanel>
        </DataTemplate>
     </ListBox.ItemTemplate>
  </ListBox>
</Grid>
</UserControl>

在后面

  using System;
  using System.Collections.Generic;
  using System.Globalization;
  using System.Linq;
  using System.Windows.Controls;
  using System.Windows.Controls.Primitives;
  using System.Windows.Data;

  namespace RowNumber
  {
     public class ListItemIndexConverter : IValueConverter
     {
        // Value should be ListBoxItem that contains the current record. RelativeSource={RelativeSource AncestorType=ListBoxItem}
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
           var lbi = (ListBoxItem)value;
           var listBox = lbi.GetVisualAncestors().OfType<ListBox>().First();
           var index = listBox.ItemContainerGenerator.IndexFromContainer(lbi);
           // One based. Remove +1 for Zero based array.
           return index + 1;
        }
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) { throw new NotImplementedException(); }
     }
     public partial class MainPage : UserControl
     {
        public MainPage()
        {
           // Required to initialize variables
           InitializeComponent();
        }
        public List<string> Test { get { return new[] { "Foo", "Bar", "Baz" }.ToList(); } }
     }
  }

这是 Silverlight 5 中的新功能，引入了 RelativeSource 绑定。

Answer 3

David Brown 链接中的想法是使用有效的值转换器。下面是一个完整的工作示例。列表框有行号，可以按姓名和年龄排序。

XAML：

<Window x:Class="NumberedListBox.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:NumberedListBox"
    Height="300" Width="300">

    <Window.Resources>

        <local:RowNumberConverter x:Key="RowNumberConverter" />

        <CollectionViewSource x:Key="sortedPersonList" Source="{Binding Path=Persons}" />

    </Window.Resources>

    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition />
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition />
            <ColumnDefinition />
        </Grid.ColumnDefinitions>
        <ListBox 
            Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="2"
            ItemsSource="{Binding Source={StaticResource sortedPersonList}}" 
            HorizontalContentAlignment="Stretch">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal">
                        <TextBlock 
                            Text="{Binding Converter={StaticResource RowNumberConverter}, ConverterParameter={StaticResource sortedPersonList}}" 
                            Margin="5" />
                        <TextBlock Text="{Binding Path=Name}" Margin="5" />
                        <TextBlock Text="{Binding Path=Age}" Margin="5" />
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
        <Button Grid.Row="1" Grid.Column="0" Content="Name" Tag="Name" Click="SortButton_Click" />
        <Button Grid.Row="1" Grid.Column="1" Content="Age" Tag="Age" Click="SortButton_Click" />
    </Grid>
</Window>

后面的代码：

using System;
using System.Collections.ObjectModel;
using System.Windows.Data;
using System.Windows;
using System.ComponentModel;
using System.Windows.Controls;

namespace NumberedListBox
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();

            Persons = new ObservableCollection<Person>();
            Persons.Add(new Person() { Name = "Sally", Age = 34 });
            Persons.Add(new Person() { Name = "Bob", Age = 18 });
            Persons.Add(new Person() { Name = "Joe", Age = 72 });
            Persons.Add(new Person() { Name = "Mary", Age = 12 });

            CollectionViewSource view = FindResource("sortedPersonList") as CollectionViewSource;
            view.SortDescriptions.Add(new SortDescription("Name", ListSortDirection.Ascending));

            DataContext = this;
        }

        public ObservableCollection<Person> Persons { get; private set; }

        private void SortButton_Click(object sender, RoutedEventArgs e)
        {
            Button button = sender as Button;
            string sortProperty = button.Tag as string;
            CollectionViewSource view = FindResource("sortedPersonList") as CollectionViewSource;
            view.SortDescriptions.Clear();
            view.SortDescriptions.Add(new SortDescription(sortProperty, ListSortDirection.Ascending));

            view.View.Refresh();
        }
    }

    public class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }
    }
}

值转换器：

using System;
using System.Windows.Data;

namespace NumberedListBox
{
    public class RowNumberConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            CollectionViewSource collectionViewSource = parameter as CollectionViewSource;

            int counter = 1;
            foreach (object item in collectionViewSource.View)
            {
                if (item == value)
                {
                    return counter.ToString();
                }
                counter++;
            }
            return string.Empty;
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}

Answer 4

终于！如果找到一种更优雅并且可能具有更好性能的方式。 （另见Accessing an ItemsControl item as it is added）

我们为此“滥用”ItemsControl.AlternateIndex 属性。最初它旨在以不同方式处理ListBox 中的每一行。 （见http://msdn.microsoft.com/en-us/library/system.windows.controls.itemscontrol.alternationcount.aspx）

1.将 AlternatingCount 设置为 ListBox 中包含的项目数量

<ListBox ItemsSource="{Binding Path=MyListItems}"
         AlternationCount="{Binding Path=MyListItems.Count}"
         ItemTemplate="{StaticResource MyItemTemplate}"
...
/>

2。绑定到 AlternatingIndex 你的 DataTemplate

<DataTemplate x:Key="MyItemTemplate" ... >
    <StackPanel>
        <Label Content="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TemplatedParent.(ItemsControl.AlternationIndex)}" />
        ...
    </StackPanel>
</DataTemplate>

因此，这无需转换器、额外的CollectionViewSource，最重要的是无需暴力搜索源集合。

Answer 5

这应该让你开始：

http://weblogs.asp.net/hpreishuber/archive/2008/11/18/rownumber-in-silverlight-datagrid-or-listbox.aspx

它说它适用于 Silverlight，但我不明白为什么它不适用于 WPF。基本上，您将 TextBlock 绑定到您的数据并使用自定义值转换器来输出当前项目的编号。