WPF - How to have certain ListView items span columns?

Question

I have a set of data that I'd like to present via a WPF ListView in this way:

Column1   Column2   Column3
--GroupName1--
Item1     part2     part3
Item2     part2     part3
--GroupName2--
Item3     part2     part3
Item4     long_text_in_both_columns
Item5     part2     part3
--GroupName1--
Item6     part2     part3
Item7     long_text_in_both_columns
--GroupName3--
Item8     part2     part3

I am starting by working with this basic sample: http://msdn.microsoft.com/en-us/library/ms771309(VS.90).aspx

Item4 and Item7 above have long text that I would like to span the remaining columns (ignoring what the original column headings were for). How can I do this?

I already have some XAML setup with a DataTrigger to replace the default GridViewRowPresenter with a custom TextBlock, but this isn't quite what I'm looking for. I need the data in column 1 to be displayed normally and the width of the first column recognized.

Answer 1

Here's how I ended up solving this with a proper ListView:

        <ListView.ItemContainerStyle >
            <Style TargetType="ListViewItem">
                <Style.Triggers>
                    <DataTrigger Binding="{Binding ShowAcrossColumns}" Value="True">
                        <Setter Property="Template">
                            <Setter.Value>
                                <ControlTemplate TargetType="{x:Type ListViewItem}">
                                    <Grid>
                                        <Grid>
                                            <Grid.ColumnDefinitions>
                                                <ColumnDefinition Width="{Binding ElementName=myListView, Path=View.Columns[0].Width}" />
                                                <ColumnDefinition Width="*" />
                                            </Grid.ColumnDefinitions>
                                            <TextBlock Grid.Column="0" Padding="6,3,6,3" Text="{Binding Column1Text}" />
                                            <TextBlock Grid.Column="1" Padding="6,3,6,3" Text="{Binding ColumnSpanningText}" />
                                        </Grid>
                                    </Grid>
                                </ControlTemplate>
                            </Setter.Value>
                        </Setter>
                    </DataTrigger>
                </Style.Triggers>
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type ListViewItem}">
                            <Grid>
                                <GridViewRowPresenter />
                            </Grid>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
        </ListView.ItemContainerStyle>

The key is that the DataTriggered Template does not use GridViewRowPresenter, and instead fakes the use of it with its own grid. Some of the padding/margins had to be guessed at to sort of match what GridViewRowPresenter uses internally. The other tricky part was binding the internal Grid columns to the overall ListView column widths. Resizing columns then works as expected.