WPF将ListView选定的项目传递给另一个ListView

Question

I have a list view with some items in the main window. Then I add checked boxes so that when an item is selected it also get checked.

Now I tried to pass the selected items from that list view to another list view but here is what I get:

Here is my XAML:

<Window x:Class="WpfApp1.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:WpfApp1"
    mc:Ignorable="d"
    Title="MainWindow" Height="350" Width="525">
<Grid>
    <Canvas HorizontalAlignment="Left" Height="299" Margin="10,10,0,0" VerticalAlignment="Top" Width="497">
        <TabControl Height="279" Canvas.Left="10" Canvas.Top="10" Width="477">
            <TabItem Header="TabItem">
                <Grid Background="#FFE5E5E5">
                    <ListView Name="lv1" Margin="0,0,0,0" HorizontalAlignment="Left" VerticalAlignment="Top" Height="110" Width="471">
                        <ListViewItem>
                            <CheckBox >
                                <StackPanel Orientation="Horizontal">
                                    <TextBlock Text="Apple"/>
                                </StackPanel>
                            </CheckBox>
                        </ListViewItem>
                        <ListViewItem>
                            <CheckBox >
                                <StackPanel Orientation="Horizontal">
                                    <TextBlock Text="Orange"/>
                            </StackPanel>
                            </CheckBox>
                        </ListViewItem>
                    </ListView>
                    <Button Content="Copy" Width="100" Height="25" Click="Button_Click"/>
                    <ListView Name="lv2" HorizontalAlignment="Left" VerticalAlignment="Bottom" Height="110" Width="471"/>
                </Grid>
            </TabItem>
            <TabItem Header="TabItem">
                <Grid Background="#FFE5E5E5"/>
            </TabItem>
            <TabItem Header="TabItem">
                <Grid Background="#FFE5E5E5"/>
            </TabItem>
            <TabItem Header="TabItem">
                <Grid Background="#FFE5E5E5"/>
            </TabItem>
            <TabItem Header="TabItem">
                <Grid Background="#FFE5E5E5"/>
            </TabItem>
            <TabItem Header="TabItem">
                <Grid Background="#FFE5E5E5"/>
            </TabItem>
            <TabItem Header="TabItem">
                <Grid Background="#FFE5E5E5"/>
            </TabItem>
        </TabControl>
    </Canvas>

</Grid>

Here is code behind in c#:

using System;
using System.Collections.Generic;
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 WpfApp1
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        List<string> lv1list = new List<string>();
        foreach (var i in lv1.SelectedItems)
        {
            lv1list.Add(i.ToString());
        }
        lv2.Items.Add(lv1.SelectedItems);
        }
    }
}

What went wrong here?

Answer 1

I made some more modifications and then I realized it is not working as it should. I have a "foreach statement" looping through all the checked/selected items in listBox1, then inside the "foreach statement" there is an "If statement" to check if the checked/selected items from listBox1 are not in listBox2, if they aren't then they are copied to listBox2. Each condition of the "If statement" should display relevant MessageBox. The problem now is that the "If statement" doesn't work properly. I know this, because I cannot see the correct relevant MessageBox to the correct condition of the "If statement". However the items are not duplicated, meaning they are not being copied over and over only they appear duplicated in the MessageBox. Here is my code and hope someone can spot my mistake

using System.Windows;
using System.Windows.Controls;
using System.Collections.Generic;
using System.ComponentModel;
using System.Windows.Controls.Primitives;
using System.Windows.Media;
using System;

namespace MYNAMESPACE
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>

public partial class MainWindow : INotifyPropertyChanged
{
    public MainWindow()
    {
        InitializeComponent();
        // To initialise the List and use it outside the class
        //MyListItem instanceOfClass = new MyListItem();
        //List<CheckBoxListItem> listOfItems = instanceOfClass.MyMethod();
        //listBox1.ItemsSource = listOfItems;
    }

    public class CheckBoxListItem : INotifyPropertyChanged
    {
        public bool CheckStatus { get; set; }
        public string Text { get; set; }
        public CheckBoxListItem(bool _CheckStatus, string _Text)
        {
            CheckStatus = _CheckStatus;
            Text = _Text;
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }

    public class MyListItem
    {
        public List<CheckBoxListItem> MyMethod()
        {
            List<CheckBoxListItem> items = new List<CheckBoxListItem>();
            items.Add(new CheckBoxListItem(false, "Item 1"));
            items.Add(new CheckBoxListItem(false, "Item 2"));
            items.Add(new CheckBoxListItem(false, "Item 3"));

            return items;
        }
    }

    public List<string> selectedNames = new List<string>();
    private void CheckBox_Click(object sender, RoutedEventArgs e)
    {
        var checkBox = sender as CheckBox;
        var item = checkBox.Content;
        bool isChecked = checkBox.IsChecked.HasValue ? checkBox.IsChecked.Value : false;

        if (isChecked)
            selectedNames.Add(item.ToString());
        else
            selectedNames.Remove(item.ToString());
    }

    public string selections;
    bool updatedItems;
    public void Button_Click(object sender, RoutedEventArgs e)
    {
        foreach (string selection in selectedNames)
        {
            selections += selection + Environment.NewLine;

            if (!listBox2.Items.Contains(selection))
            {
                listBox2.Items.Add(selection);
                updatedItems = true;
            }

            else if (listBox2.Items.Contains(selection))
            {
                updatedItems = false;
            }
        }

        if (updatedItems == true)
            MessageBox.Show("Add items are: " + selections);

        else if (updatedItems == false)
            MessageBox.Show("No update to selection was made.");
    }

    private void CheckStatus(string propName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));
    }
    public event PropertyChangedEventHandler PropertyChanged;
    }
   }

Answer 2

The problem is you're adding a complete list as an item which is why you're getting the (Collection) value.

What you can do is get all the selected item in a list them loop and add them one by one

private void Button_Click(object sender, RoutedEventArgs e)
{
    var selectedItems = lv1.SelectedItems;

    for(int i = 0; i < selectedItems.Count; i++)
    {
        lv2.Items.Add(selectedItems[i]);
    }
}

You might also want to clear your lv2 before adding the new values

lv2.Items.Clear();

---

Another option which wouldn't require you to press a button so that the values appear in the second listview would be to bind the ItemsSource of your lv2 to the SelectedItems of your lv1

lv2.ItemsSource = lv1.SelectedItems;

You can do that once at the beginning and lv2 will always contain the selected items of lv1 and will update as soon as the selected items changes.