Question

I want to create a 2 way bind between a listbox and a .NET list.

In my GUI, I have a listbox, a textbox and add and remove buttons.
The listbox displays cars, and my goal is to create a two-way bind between the .Net car list and the listbox: when the user enters a car into the textbox, it gets updated only in the .Net list, and the listbox is updated automatically.

When the user press the GUI “remove” button, a car gets removed from the GUI and the .Net list is updated automatically.

I’ve started to write the xaml code, but figured that I don’t actually know how to do the binding on both sides (c# and xaml):

<Window x:Class="WpfApplication1.Window1" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:c="clr-namespace:WpfApplication1"
    Title="Window1" Height="300" Width="369" Loaded="Window_Loaded">
    <Window.Resources>
        <ObjectDataProvider x:Key="carsData" 
                        ObjectType="{x:Type c:Window1}" />
    </Window.Resources>
    <Grid Width="332">
        <ListBox Margin="10,62,0,100" Name="myListBox" HorizontalAlignment="Left" Width="120" ItemsSource="{Binding Source={StaticResource CarsData}}"/>
        <Button Height="23" Margin="66,0,0,65" Name="addBtn" VerticalAlignment="Bottom" Click="addBtn_Click" HorizontalAlignment="Left" Width="64">add</Button>
        <TextBox Margin="10,0,0,64.48" Name="myTextBox" Height="23" VerticalAlignment="Bottom" HorizontalAlignment="Left" Width="47" />
        <Button Height="23" Margin="66,0,0,33" Name="removeButton" VerticalAlignment="Bottom" HorizontalAlignment="Left" Width="64" Click="removeButton_Click">Remove</Button>
    </Grid>
</Window>

There is my c# code:

public partial class Window1 : Window
{
    MyModel listMgr;
    ObservableCollection<Car> carList;

    public Window1()
    {
        InitializeComponent();
        listMgr = new MyModel();
    }

    private void addBtn_Click(object sender, RoutedEventArgs e)
    {
        listMgr.add(new Car(0, myTextBox.Text, 2011));

    }

    private void removeButton_Click(object sender, RoutedEventArgs e)
    {
        //myListBox.Items.RemoveAt(0);
    }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        carList = listMgr.getList();
        myListBox.DataContext = carList;
        //secondListBox.DataContext = carList;
    }
}

Answer 1

This is a quick version, you’ll need to add code to check the car is selected, etc.

To see your Car data you’ll need to define a data template. In the example it’s just a simple name, but you can change the text colour, font size, add more fields, etc.

It’s best to work on the list when adding / removing cars, not on the ListBox directly.

XAML:

<Window x:Class="cars.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<Window.Resources>
    <DataTemplate x:Key="car_template" DataType="Car">
        <TextBlock Text="{Binding name}"/>
    </DataTemplate>
</Window.Resources>
<StackPanel>
    <ListBox x:Name="cars_box" Margin="5" ItemsSource="{Binding}" ItemTemplate="{StaticResource car_template}"/>
    <TextBox x:Name="new_car_box" Margin="5"/>
    <Button Content="add" Click="add_car" Margin="5"/>
    <Button Content="delete" Click="delete_car" Margin="5"/>
</StackPanel>

C#:

using System.Collections.ObjectModel;
using System.Windows;    
public partial class MainWindow : Window
{
    ObservableCollection<Car> cars = new ObservableCollection<Car>();
    public MainWindow()
    {
        InitializeComponent();            
        cars.Add(new Car("Volvo"));
        cars.Add(new Car("Ferrari"));
        cars_box.DataContext = cars;
    }

    private void add_car(object sender, RoutedEventArgs e)
    {
        cars.Add(new Car(new_car_box.Text));
    }

    private void delete_car(object sender, RoutedEventArgs e)
    {
        cars.Remove((cars_box.SelectedItem as Car));
    }
}

public class Car
{
    public string name { get; set; }
    public Car(string _name)
    {
        this.name = _name;
    }
}