Looking for a WPF ComboBox with checkboxes

There is my combobox. I use Martin Harris code and code from this link Can a WPF ComboBox display alternative text when its selection is null?

<ComboBox Name="cbObjects" Grid.Column="1" Grid.Row="1" VerticalAlignment="Center" Margin="2,2,6,0" SelectionChanged="OnCbObjectsSelectionChanged" >
    <ComboBox.ItemTemplate>
        <DataTemplate>
            <StackPanel Orientation="Horizontal">
                <CheckBox IsChecked="{Binding IsSelected}" Width="20" VerticalAlignment="Center" Checked="OnCbObjectCheckBoxChecked" Unchecked="OnCbObjectCheckBoxChecked" />
                <TextBlock Text="{Binding ObjectData}" VerticalAlignment="Center" />
            </StackPanel>
        </DataTemplate>
    </ComboBox.ItemTemplate>
</ComboBox>
<TextBlock IsHitTestVisible="False" Name="tbObjects" Text="Выберите объекты..." Grid.Column="1" Grid.Row="1" VerticalAlignment="Center" Margin="6,2,6,0" />

Small class for datasource:

public class SelectableObject <T> {
    public bool IsSelected { get; set; }
    public T ObjectData { get; set; }

    public SelectableObject(T objectData) {
        ObjectData = objectData;
    }

    public SelectableObject(T objectData, bool isSelected) {
        IsSelected = isSelected;
        ObjectData = objectData;
    }
}

And there is two handler - one for handling CheckBox clicked and one for forming Text for ComboBox.

private void OnCbObjectCheckBoxChecked(object sender, RoutedEventArgs e) {
    StringBuilder sb = new StringBuilder();
    foreach (SelectableObject<tblObject> cbObject in cbObjects.Items) 
    {
        if (cbObject.IsSelected)
            sb.AppendFormat("{0}, ", cbObject.ObjectData.Description);
    }
    tbObjects.Text = sb.ToString().Trim().TrimEnd(',');
}

private void OnCbObjectsSelectionChanged(object sender, SelectionChangedEventArgs e) {
    ComboBox comboBox = (ComboBox)sender;
    comboBox.SelectedItem = null;
}

For ComboBox.ItemsSource I use

ObservableCollection<SelectableObject<tblObject>> 

where tblObject is type of my object, a list of which I want to display in ComboBox.

I hope this code is useful to someone!

Give a try to CheckComboBox from Extended WPF Toolkit. The main advantage for me is having two lists for binding:

• all items available for selection
• just selected items

I find this approach more practical. In addition you can specify value and display members of the collections you're binding.

If you don't want to bring a bunch of other controls with CheckComboBox, you can get the source code of it, it's pretty straightforward (need to bring Selector class as well).

You can do this yourself by setting the DataTemplate of the combo box. This article shows you how - for a listbox, but the principle is the same.

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Another article here is perhaps a better fit for what you are trying to do, simple set the first column of the item template to be a checkbox and bind it to a bool on your business object.

<ComboBox.ItemTemplate>
    <DataTemplate>
        <StackPanel Orientation="Horizontal">
            <CheckBox IsChecked="{Binding IsSelected}"
                       Width="20" />
            <TextBlock Text="{Binding DayOfWeek}"
                       Width="100" />
        </StackPanel>
    </DataTemplate>
</ComboBox.ItemTemplate>