How to filter listbox in WPF

Question

How to filter listbox in WPF

Answer 1

Refer below link for filter using ICollectionView and CollectionViewSource.
Auto-complete-quick-search-WPF-ListBox

Below very sample filtering, added data in XAML code only, you can bind listbox as per your need.
C# Code:

using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
namespace WpfListboxSearch
{
    public partial class MainWindow : Window
    {
        List<string> Namelist = new List<string>();
        public MainWindow()
        {
            InitializeComponent();

            foreach (ListBoxItem lbi in lbNameList.Items)
            {
                Namelist.Add(lbi.Content.ToString());
            }
        }
        private void txtNameSearch_TextChanged(object sender, TextChangedEventArgs e)
        {
            if (!string.IsNullOrWhiteSpace(txtNameSearch.Text))
            {
                lbNameList.Items.Clear();
                foreach (string name in Namelist)
                {
                    if (name.ToLower().StartsWith(txtNameSearch.Text.Trim().ToLower()))
                    {
                        lbNameList.Items.Add(name);
                    }
                }
            }
            else if (string.IsNullOrWhiteSpace(txtNameSearch.Text))
            {
                lbNameList.Items.Clear();

                foreach (string name in Namelist)
                {
                    lbNameList.Items.Add(name);
                }
            }
        }
    }
}

XAML Code:

<Window x:Class="WpfListboxSearch.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfListboxSearch"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <TextBox Height="23" HorizontalAlignment="Left" Margin="82,11,0,0" Name="txtNameSearch" VerticalAlignment="Top" Width="120" TextChanged="txtNameSearch_TextChanged"/>
        <ListBox Height="100" HorizontalAlignment="Left" Margin="86,51,0,0" Name="lbNameList" VerticalAlignment="Top" Width="600" >
            <ListBoxItem>David</ListBoxItem>
            <ListBoxItem>Rock</ListBoxItem>
            <ListBoxItem>Shaan</ListBoxItem>
        </ListBox>
    </Grid>
</Window>