在使用用户定义模板的菜单项中插入图标

Question

I want to have a dropdown menu with custom background color of the menu item. I was able to achieve this with the help of this answer . The root menu item in my GUI has only an icon with no Header . The code I used to define the menu item icon is as follows:

<Style x:Key="MenuIcon" TargetType="{x:Type MenuItem}">
    <Setter Property="SnapsToDevicePixels" Value="True" />
    <Setter Property="OverridesDefaultStyle" Value="True" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type MenuItem}">
                 <Menu Background="Orange">
                     <MenuItem ToolTip="Menu" BorderBrush="White">
                          <MenuItem.Header>
                               <StackPanel
                                   Width="60"
                                   Height="50"
                                   HorizontalAlignment="Center"
                                   VerticalAlignment="Center"
                                   Background="Orange"
                                   Orientation="Horizontal">
                                   <Viewbox
                                       Margin="9"
                                       HorizontalAlignment="Center"
                                       VerticalAlignment="Center"
                                       Stretch="Fill">
                                       <Grid Margin="-8,0,0,0">
                                          <Path
                                              x:Name="MenuIconFillStyle"
                                              HorizontalAlignment="Center"
                                              VerticalAlignment="Center"
                                              Data="M6 36v-3h36v3Zm0-10.5v-3h36v3ZM615v-3h36v3Z"
                                              Fill="White" />
                                       </Grid>
                                   </Viewbox>
                               </StackPanel>
                           </MenuItem.Header>
                        </MenuItem>
                     </Menu>

                    <ControlTemplate.Triggers>
                        <Trigger Property="IsMouseOver" Value="True">
                             <Setter TargetName="MenuIconFillStyle" Property="Fill" Value="Yellow" />
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

I added the following in the <ControlTemplate x:Key="MenuItemControlTemplate1" TargetType="{x:Type MenuItem}"> taken from here :

 <ContentPresenter x:Name="Icon" Content="{TemplateBinding Icon}" ContentSource="Icon" HorizontalAlignment="Center" Height="16" Margin="3" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center" Width="16"/>

and the following in the ControlTemplate.Triggers :

<Trigger Property="Icon" Value="True">
     <Setter Property="Visibility" TargetName="Icon" Value="Visible"/>
</Trigger>

The Template="{DynamicResource MenuItemControlTemplate1}" is as follows:

<ControlTemplate x:Key="MenuItemControlTemplate1" TargetType="{x:Type MenuItem}">
            <Border x:Name="templateRoot" 
                    BorderBrush="#535353" 
                    CornerRadius="3" 
                    BorderThickness="1" 
                    Background="{TemplateBinding Background}" 
                    SnapsToDevicePixels="True">
                <Grid VerticalAlignment="Center">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto"/>
                        <ColumnDefinition Width="Auto"/>
                    </Grid.ColumnDefinitions>

                    <ContentPresenter x:Name="Icon" Content="{TemplateBinding Icon}" ContentSource="Icon" HorizontalAlignment="Center" Width="26" Height="16" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Center" />
                    <ContentPresenter ContentTemplate="{TemplateBinding HeaderTemplate}" Content="{TemplateBinding Header}" Grid.Column="1" ContentStringFormat="{TemplateBinding HeaderStringFormat}" ContentSource="Header" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                    <Popup x:Name="PART_Popup"  AllowsTransparency="True" Focusable="False" IsOpen="{Binding IsSubmenuOpen, RelativeSource={RelativeSource TemplatedParent}}" PopupAnimation="{DynamicResource {x:Static SystemParameters.MenuPopupAnimationKey}}" Placement="Bottom" HorizontalOffset="-2">
                        <Border x:Name="SubMenuBorder" BorderBrush="#595959" BorderThickness="1" Background="#3A3A3A" Padding="2">
                            <ScrollViewer x:Name="SubMenuScrollViewer" Style="{DynamicResource {ComponentResourceKey ResourceId=MenuScrollViewer, TypeInTargetAssembly={x:Type FrameworkElement}}}">
                                <Grid RenderOptions.ClearTypeHint="Enabled">
                                    <Canvas HorizontalAlignment="Left" Height="0" VerticalAlignment="Top" Width="0">
                                        <Rectangle x:Name="OpaqueRect" Fill="{Binding Background, ElementName=SubMenuBorder}" Height="{Binding ActualHeight, ElementName=SubMenuBorder}" Width="{Binding ActualWidth, ElementName=SubMenuBorder}"/>
                                    </Canvas>
                                    <ItemsPresenter x:Name="ItemsPresenter" KeyboardNavigation.DirectionalNavigation="Cycle" Grid.IsSharedSizeScope="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" KeyboardNavigation.TabNavigation="Cycle"/>
                                </Grid>
                            </ScrollViewer>
                        </Border>
                    </Popup>
                </Grid>
            </Border>
            <ControlTemplate.Triggers>
                <Trigger Property="Icon" Value="True">
                    <Setter Property="Visibility" TargetName="Icon" Value="Visible"/>
                </Trigger>
                <Trigger Property="IsSuspendingPopupAnimation" Value="True">
                    <Setter Property="PopupAnimation" TargetName="PART_Popup" Value="None"/>
                </Trigger>
                <Trigger Property="IsHighlighted" Value="True">
                    <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource DarkBrush}"/>
                    <Setter Property="BorderBrush" TargetName="templateRoot" Value="#2C2C2C"/>
                    <Setter Property="BorderThickness" TargetName="templateRoot" Value="1"></Setter>
                </Trigger>

                <Trigger Property="CanContentScroll" SourceName="SubMenuScrollViewer" Value="False">
                    <Setter Property="Canvas.Top" TargetName="OpaqueRect" Value="{Binding VerticalOffset, ElementName=SubMenuScrollViewer}"/>
                    <Setter Property="Canvas.Left" TargetName="OpaqueRect" Value="{Binding HorizontalOffset, ElementName=SubMenuScrollViewer}"/>
                </Trigger>
                <Trigger Property="IsKeyboardFocusWithin" Value="True">
                    <Setter TargetName="templateRoot" Property="Background" Value="{StaticResource Clicked}" />
                    <Setter Property="Header" Value="Test" />
                    <Setter Property="BorderBrush" Value="#2C2C2C"></Setter>
                    <Setter Property="BorderThickness" Value="1"></Setter>
                </Trigger>
            </ControlTemplate.Triggers>
        </ControlTemplate>

The custom background and the icon for the MenuItem is specified as in the following code snippet:

<Grid Background="#535353">
    <Menu Width="100" Height="22" Margin="10, 10, 5, 5" HorizontalAlignment="Left" Background="White" VerticalAlignment="Top">
        <MenuItem Style="{StaticResource MenuIcon}" Template="{DynamicResource MenuItemControlTemplate1}">
    </Menu>
</Grid>

The icon defined in Style is not rendering in the MenuItem along with the Template ( Template="{DynamicResource MenuItemControlTemplate1}" ) used for setting the background color. How can this be achieved?

Edit

Based on the suggestion of @mm8, I tried to combine the Styles that are responsible for changing the background color (The Style with x:Key="TopLevelHeaderStyle" which is borrowed from here ) and inserting a menu item icon in the root menu and came up with the following:

 <Style x:Key="TopLevelHeaderStyle" TargetType="{x:Type MenuItem}">
            <Setter Property="Background" Value="#000d18"/>
            <Setter Property="Foreground" Value="#d8d8d8"/>
            <Setter Property="Width" Value="72"/>
            <Setter Property="Height" Value="42"/>
            <Setter Property="FontSize" Value="16"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type MenuItem}">
                        <Border x:Name="MenuItemBorder" Width="72" Height="42" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}">
                            <Grid VerticalAlignment="Center">
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="Auto"/>
                                    <ColumnDefinition Width="Auto"/>
                                </Grid.ColumnDefinitions>
                                <ContentPresenter Content="{TemplateBinding Header}" ContentSource="Header" Margin="{TemplateBinding Padding}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                                <Popup AllowsTransparency="True" IsOpen="{Binding IsSubmenuOpen, RelativeSource={RelativeSource TemplatedParent}}" Placement="Bottom" PlacementTarget="{Binding ElementName=MenuItemBorder}"
                                   HorizontalOffset="1" VerticalOffset="-1">
                                    <Border BorderBrush="#414141" Background="#414141">
                                        <ScrollViewer Style="{DynamicResource {ComponentResourceKey ResourceId=MenuScrollViewer, TypeInTargetAssembly={x:Type FrameworkElement}}}">
                                            <ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                                        </ScrollViewer>
                                    </Border>
                                </Popup>
                            </Grid>
                        </Border>
                        <ControlTemplate.Triggers>
                            <Trigger Property="IsHighlighted" Value="True">
                                <Setter Property="Background" Value="#1271C8"/>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

        <!--MenuIcon-->
        <Style x:Key="MenuIcon" TargetType="{x:Type MenuItem}" BasedOn="{StaticResource TopLevelHeaderStyle}">
            <Setter Property="SnapsToDevicePixels" Value="True" />
            <Setter Property="OverridesDefaultStyle" Value="True" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type MenuItem}">
                        <Menu>
                            <MenuItem>
                                <MenuItem.Header>
                                    <StackPanel
                            Width="60"
                            Height="50"
                            HorizontalAlignment="Center"
                            VerticalAlignment="Center"
                            Background="Orange"
                            Orientation="Horizontal">
                                        <Viewbox
                                Margin="9"
                                HorizontalAlignment="Center"
                                VerticalAlignment="Center"
                                Stretch="Fill">
                                            <Grid Margin="-8,0,0,0">
                                                <Path x:Name="MenuIconFillStyle"
                                        HorizontalAlignment="Center"
                                        VerticalAlignment="Center"
                                        Fill="White"              
                                        Data="M6 36v-3h36v3Zm0-10.5v-3h36v3ZM6 15v-3h36v3Z"
                                       />
                                            </Grid>
                                        </Viewbox>
                                    </StackPanel>
                                </MenuItem.Header>
                            </MenuItem>
                        </Menu>

And used it as follows:

<Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="50" />
            <RowDefinition />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="auto" />
            <ColumnDefinition Width="auto" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>


        <Menu Grid.Column="0" FontSize="24" HorizontalAlignment="Left" VerticalAlignment="Top">
            <MenuItem  Header="File" Style="{StaticResource TopLevelHeaderStyle}">
                <MenuItem Header="New"/>
                <MenuItem Header="Open"/>
                <MenuItem Header="Close"/>
            </MenuItem>
        </Menu>

        <Menu Grid.Column="1"  FontSize="24" HorizontalAlignment="Left" VerticalAlignment="Top">
            <MenuItem Margin="-11, 0,0,0" Width="50" Header="File" Style="{StaticResource MenuIcon}">
                <MenuItem Header="New1"/>
                <MenuItem Header="Open1"/>
                <MenuItem Header="Close1"/>
            </MenuItem>
        </Menu>
    </Grid>

Now the drop down menu having an icon in the root menu item is not showing the other menu item contents New1 , Open1 and Close1 What mistake am I making?

Answer 1

The MenuItem control has a DependencyProperty of type Object named 'Icon'. This property is reserved for your exact purpose.

First you need to bind the Data in the Path within your MenuItem ControlTemplate to the Icon property of the parent MenuItem. Like this:

<Path x:Name="MenuIconFillStyle"
   HorizontalAlignment="Center"
   VerticalAlignment="Center"
   Data="{TemplateBinding Icon}"
   Fill="White" />

Now you may specify a PathGeometry in XAML like this. Its contents will be your SVG data:

<PathGeometry x:Key="MySpecialPath">M2 0C0.89687</PathGeometry>

Finally, apply this path using its Key to any MenuItem as a StaticResource:

<Menu Width="100" Height="22" Margin="10, 10, 5, 5" HorizontalAlignment="Left" Background="White" VerticalAlignment="Top">
    <MenuItem Template="{DynamicResource MenuItemControlTemplate1}"
              Icon="{StaticResource MySpecialPath}">
</Menu>

If you want a bit more control out of your icons (multiple colors, different size, margin, etc..) It is a bit more involved. Just remember that the 'Path' property on MenuItem is an Object so you can hypothetically use any 'Presenting' element (Does not need to be Path) in your MenuItem ControlTemplate and TemplateBind it to MenuItem.Path - then pass any type of 'Presented' object to the MenuItem (does not need to be PathGeometry). You can look into using a

<ContentPresenter Content="{TemplateBinding Icon}" />

instead of the Path control in the MenuItem ControlTemplate - and then giving literally any "Icon" control to your MenuItem.Path property in your XAML.