WPF Combobox: Different template in textbox and drop-downlist

Question

This is my combo-box.

    <ComboBox Height="45" HorizontalAlignment="Left" Margin="184,66,0,0" Name="ComboBox1" VerticalAlignment="Top" Width="216">
        <ComboBox.ItemTemplate>
            <DataTemplate>
                <StackPanel Orientation="Horizontal">
                    <Label Content="{Binding FullName}" Width="150" />
                    <Label Content="{Binding Title}" Width="100"/>
                    <Label Content="{Binding BranchName}" />
                </StackPanel>
            </DataTemplate>
        </ComboBox.ItemTemplate>
    </ComboBox>

How can I change it so that only the FullName appears in the textbox portion of the combobox while all three columns still appear in the drop-down portion?

Answer 1

Unfortunately, the SelectionBoxItemTemplate is a readonly property, so we have to do a bit more work. By doing the ItemTemplate to be how you want the item to appear when selected, you can edit the ItemContainerStyle to provide a ControlTemplate that includes the other fields you want to display.

<ComboBox Height="45" HorizontalAlignment="Left" Margin="184,66,0,0" Name="ComboBox1" VerticalAlignment="Top" Width="216">
    <ComboBox.ItemTemplate>
        <DataTemplate>
            <Label Content="{Binding FullName}" Width="150" />
        </DataTemplate>
    </ComboBox.ItemTemplate>
    <ComboBox.ItemContainerStyle>
        <Style TargetType="{x:Type ComboBoxItem}">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type ComboBoxItem}">
                        <Border x:Name="Bd"
                                BorderBrush="{TemplateBinding BorderBrush}"
                                BorderThickness="{TemplateBinding BorderThickness}"
                                Background="{TemplateBinding Background}">
                            <StackPanel Orientation="Horizontal">
                                <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
                                                  VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
                                <Label Content="{Binding Title}" Width="100"/>
                                <Label Content="{Binding BranchName}" />
                            </StackPanel>
                        </Border>
                        <ControlTemplate.Triggers>
                            <Trigger Property="IsHighlighted" Value="True">
                                <Setter TargetName="Bd" Property="Background" Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}" />
                                <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.HighlightTextBrushKey}}" />
                            </Trigger>
                            <Trigger Property="IsEnabled" Value="False">
                                <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </ComboBox.ItemContainerStyle>
</ComboBox>

For the ComboBoxItem template, I just modified the default one, so it should be fully functional.

Answer 2

If the ComboBox's IsEditable property is set to True, you can set the "TextSearch.TextPath" property of the ComboBox to the property name you want to show. So in your case:

<ComboBox IsEditable="True" TextSearch.TextPath="FullName" .../>

Answer 3

There is a pretty good answer to your question here if you don't want to change the ComboBoxes style: https://stackoverflow.com/a/2277488/1070906

It uses a Trigger in the DataTemplate which looks if there is a ComboBoxItem somewhere above in the visual tree, which is not the case in the selection box.