<Window x:Class="WpfApp18.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:WpfApp18"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <StackPanel>
        <ListBox x:Name="ttt">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <Grid>
                    
                        <Grid.ColumnDefinitions>

                            <ColumnDefinition/>
                            <ColumnDefinition/>
                          
                        </Grid.ColumnDefinitions>

                        <CheckBox Grid.Column="0" Tag="{Binding P_Idx}"> ssss</CheckBox>
                        <Label Content="{Binding P_Name}" Grid.Column="1"></Label>
                    </Grid>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
        <Button x:Name="ddds" Click="ddds_Click" Content="체크된값 가져오기"/>
    </StackPanel>
</Window>

비하인드
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApp18
{
    /// <summary>
    /// MainWindow.xaml에 대한 상호 작용 논리
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            SetLoad();
        }

        private void SetLoad()
        {
            List<Cust> li = new List<Cust>();
            li.Add(new Cust() { P_idx = "1111", P_Name = "영민" });
            li.Add(new Cust() { P_idx = "2222", P_Name = "영민2" });
            li.Add(new Cust() { P_idx = "3333", P_Name = "영민3" });
            ttt.ItemsSource = li;
        }

        private void ddds_Click(object sender, RoutedEventArgs e)
        {
            foreach (Cust item in ttt.Items)
            {
                ==>여기서 어떻게 구현해야 checkbox에 체크된 tag값을 읽어올수있을가요?

            }
        }
    }


    public class Cust
    {
        public CheckBox ccc { get; set; }
        public string P_idx { get; set; }
        public string P_Name { get; set; }
    }
}

감사합니다...

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