WPF ComboBoxAdv MultiSelection

This repository demonstrates how to select items programmatically in the Syncfusion WPF ComboBoxAdv control and enable multi-selection functionality.

Why Use ComboBoxAdv MultiSelection?

• Allows users to select multiple items from a dropdown list.
• Supports data binding for dynamic item updates.
• Ideal for scenarios like filtering, tagging, or multi-choice forms.

Creating project

Follow these steps to create a new WPF project in Visual Studio and add the ComboBoxAdv control:

Adding Control Manually in XAML

1. Add the required assembly reference:

   • Syncfusion.Shared.WPF

2. Import the Syncfusion WPF schema:

xmlns:syncfusion="http://schemas.syncfusion.com/wpf"

3. Declare the ComboBoxAdv in XAML:

<Grid>
    <syncfusion:ComboBoxAdv Height="30" Width="150"/>
</Grid>

Adding Control Manually in C#

1. Add the required assembly reference:

   • Syncfusion.Shared.WPF

2. Import the namespace:

using Syncfusion.Windows.Tools.Controls;

3. Create and configure the ComboBoxAdv instance:

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        ComboBoxAdv comboBoxAdv = new ComboBoxAdv
        {
            Height = 30,
            Width = 150,
            DefaultText = "Choose Items"
        };
        this.Content = comboBoxAdv;
    }
}

ComboBoxAdv MultiSelection Example

Enable multi-selection and bind data using MVVM:

[XAML]

<Window.DataContext>
    <local:ViewModel />
</Window.DataContext>

<Grid>
    <syncfusion:ComboBoxAdv DisplayMemberPath="Name"
                             SelectedItems="{Binding SelectedItems, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
                             AllowMultiSelect="True"
                             Name="comboboxadv"
                             HorizontalAlignment="Center"
                             Height="30"
                             VerticalAlignment="Center"
                             Width="150"
                             ItemsSource="{Binding Countries}"/>
</Grid>

ViewModel

public class ViewModel : INotifyPropertyChanged
{
    private ObservableCollection<object> selectedItems;
    public ObservableCollection<object> SelectedItems
    {
        get => selectedItems;
        set
        {
            selectedItems = value;
            RaisePropertyChanged(nameof(SelectedItems));
        }
    }

    public ObservableCollection<Country> Countries { get; set; }

    public ViewModel()
    {
        Countries = new ObservableCollection<Country>
        {
            new Country() { Name = "Denmark" },
            new Country() { Name = "New Zealand" },
            new Country() { Name = "Canada" },
            new Country() { Name = "Russia" },
            new Country() { Name = "Japan" }
        };

        SelectedItems = new ObservableCollection<object>(Countries.Take(2));
    }

    public event PropertyChangedEventHandler PropertyChanged;
    private void RaisePropertyChanged(string propertyName)
        => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}

public class Country
{
    public string Name { get; set; }
}