How to add a sequence number to a ListBox list item before WPF

Sometimes we might want to add a sequence number before the ListBox list item, so that it looks clearer and can be used with shortcut keys and so on.

Want to achieve the effect as follows:

Obviously we can do this by modifying the template for the ListBox, as long as you add a number to the item, you can use MultiBinding and imultivalueconverter.

Example

First, we create a person class:

public class person{Public    string Name {get; set;}}

Then create a Converter that inherits from the Imultivalueconverter:

Note that line 5th to 6th, which uses the dynamic type, must ensure that the list has IndexOf this extension method,ienumerable<t> is not possible.

public class indexconverter:imultivalueconverter{Public    object Convert (object[] values, Type targetType, Object pa Rameter, CultureInfo culture)    {        Dynamic item = values[0];        Dynamic list = values[1];        Return list. IndexOf (person) + 1;    }    Public object[] Convertback (object value, type[] targettypes, object parameter, CultureInfo culture)    {        throw new NotImplementedException ();    }}

The XAML is as follows:

The key is to 17~20 rows, each binding the individual data and the ListBox itself.

<window x:class= "Listboxindex.mainwindow" xmlns= "http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x= "Http://schemas.microsoft.com/winfx/2006/xaml" Xmlns:listboxindex = "Clr-namespace:listboxindex" T Itle= "MainWindow" Height = "width=", "525" > <Window.Resources> <listboxindex:indexconverter x:key= "Indexconverter"/> </Window.Resources> <stackpanel > <button name= "Btndemo" content= "Add" C lick= "Btndemo_onclick"/> <listbox name= "Lbxdemo" > <ListBox.ItemTemplate> &                        Lt;datatemplate datatype= "Listboxindex:person" > <stackpanel orientation= "Horizontal" >                                <textblock text= "{Binding}" > <TextBlock.DataContext> <multibinding converter= "{StaticResource indexconverter}" > <b             Inding/>                       <binding elementname= "Lbxdemo" path= "ItemsSource"/> </multi                        Binding> </TextBlock.DataContext> </TextBlock> <textblock text= "{Binding Name}"/> </StackPanel> </datatempl ate> </ListBox.ItemTemplate> </ListBox> </stackpanel ></Window>

The code is as follows:

namespace listboxindex{//<summary>//    MainWindow.xaml Interactive logic///    </summary> public    Partial class Mainwindow:window    {        readonly observablecollection <Person> _personlist = new ObservableCollection <Person> ();        Public MainWindow ()        {            InitializeComponent ();            Initsource ();        }        private void Initsource ()        {            _personlist.add (new person () {Name = "Liu Bei"})            ; _personlist.add (new person () {Name = "Guan Yu"});            Lbxdemo.itemssource = _personlist;        }        private void Btndemo_onclick (object sender, RoutedEventArgs e)        {            _personlist.add (new person () {Name = "Zhang Fei"});            lbxdemo.itemssource = _personlist;}}    }

　　

How to add a sequence number to a ListBox list item before WPF