button with context menu

button.xaml

        <Button Name="MainOptionsButton">

            <i:Interaction.Triggers>
                <i:EventTrigger EventName="Click">
                    <ei:ChangePropertyAction TargetObject="{Binding ContextMenu, ElementName=MainOptionsButton}" PropertyName="PlacementTarget" Value="{Binding ElementName=MainOptionsButton, Mode=OneWay}"/>
                    <ei:ChangePropertyAction TargetObject="{Binding ContextMenu, ElementName=MainOptionsButton}" PropertyName="IsOpen" Value="True"/>
                </i:EventTrigger>
            </i:Interaction.Triggers>

            <Button.Resources>

                <CollectionViewSource Source="{Binding LoggedInServers}" x:Key="LoggedInServers" />

            </Button.Resources>

            <Button.ContextMenu>
                <ContextMenu Placement="Top">

                    <MenuItem Header="Sign out from">

                        <MenuItem.ItemsSource>

                            <CompositeCollection>
                                <CollectionContainer Collection="{Binding Source={StaticResource LoggedInServers}}" />
                                <Separator />
                                <MenuItem Command="{Binding CmdLogout}" Header="All Servers" />
                            </CompositeCollection>

                        </MenuItem.ItemsSource>

                    </MenuItem>

                </ContextMenu>
            </Button.ContextMenu>

            <Rectangle Width="15" Height="15">
                <Rectangle.Fill>
                    <VisualBrush Stretch="Fill" Visual="{StaticResource appbar_settings}" />
                </Rectangle.Fill>
            </Rectangle>

        </Button>