How to make a WPF DataGrid with alternating row colors, and a fix color section (ignoring alternation)

Question

I have a datagrid that I'm trying to make resemble:

I'm using the AlternatingRowBackground attribute to perform the alternating colors. For the fixed color section, I have XAML that resembles:

            <DataGrid.Resources>
                <Style TargetType="{x:Type DataGridRow}">
                    <Style.Triggers>
                        <DataTrigger Binding="{Binding Path=ShouldBeFixedColor}" Value="True">
                            <DataTrigger.Setters>
                                <Setter Property="Background" Value="Blue" />
                            </DataTrigger.Setters>
                        </DataTrigger>
                    </Style.Triggers>
                </Style>
            </DataGrid.Resources>

The problem with this approach is that the "alternating color" takes precedence over the fixed color style trigger. So, at the bottom instead of blue-blue-blue it is blue-gray-blue.

Any ideas on how to archive the desired coloring? I'd rather do this all at the XAML level if possible.

Thanks!

Answer 1

Made some changes based upon other SO answers. Hopefully this helps someone in the future.

1. Yank AlternatingRowBackground=... from the grid. Add AlternationCount="2"

2. Add the block below to do the styling (manually doing the alternating rows)

           <DataGrid.RowStyle>
               <Style TargetType="{x:Type DataGridRow}">
                   <Style.Triggers>
                       <Trigger Property="AlternationIndex" Value="0">
                           <Setter Property="Background" Value="White" />
                       </Trigger>
                       <Trigger Property="AlternationIndex" Value="1">
                           <Setter Property="Background" Value="WhiteSmoke" />
                       </Trigger>
                       <DataTrigger Binding="{Binding Path=Selectable}" Value="False">
                           <DataTrigger.Setters>
                               <Setter Property="Background" Value="LightGray" />
                           </DataTrigger.Setters>
                       </DataTrigger>
                   </Style.Triggers>
               </Style>
           </DataGrid.RowStyle>