MultiSelectComboBox

1）Xaml

DrawingExampleVM DataSource

<Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"/>
                <RowDefinition/>
            </Grid.RowDefinitions>
            <Button Content="获取选中" 
                    VerticalAlignment="Bottom"
                    HorizontalAlignment="Center"
                    Click="Button_Click"
                    Margin="0,20,0,0"
                    Style="{StaticResource WarningPrimaryButton}"/>
            <UniformGrid Columns="2" Rows="2" Grid.Row="1">
                <wd:MultiSelectComboBox
                VerticalContentAlignment="Center" 
                IsSelectAllActive="True"
                HorizontalAlignment="Center"
                Delimiter="^" Width="200">
                    <wd:MultiSelectComboBoxItem>Option 1</wpfdev:MultiSelectComboBoxItem>
                    <wd:MultiSelectComboBoxItem>Option 2</wpfdev:MultiSelectComboBoxItem>
                    <wd:MultiSelectComboBoxItem>Option 3</wpfdev:MultiSelectComboBoxItem>
                    <wd:MultiSelectComboBoxItem>Option 4</wpfdev:MultiSelectComboBoxItem>
                    <wd:MultiSelectComboBoxItem>Option 5</wpfdev:MultiSelectComboBoxItem>
                </wd:MultiSelectComboBox>
                <wd:MultiSelectComboBox Name="MyMultiSelectComboBox"
                    VerticalContentAlignment="Center" 
                                        HorizontalAlignment="Center"
                                        ItemsSource="{Binding Drawings}" 
                                        DisplayMemberPath="Number"
                                        SelectedValuePath="Index"
                                        Width="200"
                                        IsSelectAllActive="True"
                                        wd:ElementHelper.Watermark="MultiSelectComboBox">
                    <wd:MultiSelectComboBox.DataContext>
                        <vm:DrawingExampleVM/>
                    </wd:MultiSelectComboBox.DataContext>
                </wpfdev:MultiSelectComboBox>
            </UniformGrid>
        </Grid>

2）CSharp

        private void Button_Click(object sender, System.Windows.RoutedEventArgs e)
        {
            WPFDevelopers.Controls.MessageBox.Show($"{MyMultiSelectComboBox.Text} \r\n总共选中:{MyMultiSelectComboBox.SelectedItems.Count} 条", "选中内容", MessageBoxButton.OK, MessageBoxImage.Information);
        }