ComboBoxItem doesn't display - wpf

Question

I have a style for ComboBox in the Popup. Here is the
Image of my ComboBoxItem
Here is a code:
<Style x:Key="ComboBoxStyle" TargetType="{x:Type ComboBox}">
<Setter Property="IsSelected" Value="{DynamicResource ComboBoxItemStyle}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ComboBox}">
<Grid>
<ToggleButton Height="{TemplateBinding Height}"
Style="{StaticResource ToggleButtonStyle}"
HorizontalAlignment="Right"
Width ="549"
IsChecked="{Binding Path=IsDropDownOpen,Mode=TwoWay,RelativeSource={RelativeSource TemplatedParent}}"
ClickMode="Press"/>
<Popup Name="Popup"
IsOpen="{TemplateBinding IsDropDownOpen}"
AllowsTransparency="True"
Focusable="False"
PopupAnimation="Fade"
VerticalOffset="10">
<Grid Name="DropDown"
SnapsToDevicePixels="True"
MinWidth="{TemplateBinding ActualWidth}"
MaxHeight="{TemplateBinding MaxDropDownHeight}">
<Border x:Name="DropDownBorder" CornerRadius="18"/>
<ScrollViewer SnapsToDevicePixels="True" VerticalScrollBarVisibility="Hidden">
<StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
</ScrollViewer>
</Grid>
</Popup>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsGrouping" Value="true">
<Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
</Trigger>
<Trigger SourceName="Popup" Property="Popup.AllowsTransparency" Value="true">
<Setter TargetName="DropDownBorder" Property="Background" Value="White"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Styles for ToggleButton and ComboBoxItems:
<Style x:Key="ToggleButtonStyle" TargetType="{x:Type ToggleButton}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition Width="520"/>
</Grid.ColumnDefinitions>
<Border x:Name="Border" Grid.ColumnSpan="2" CornerRadius="10,10,10,10" Background="White" />
<Path Data="M12,2A10,10 0 0,1 22,12A10,10 0 0,1 12,22A10,10 0 0,1 2,12A10,10 0 0,1 12,2M7,10L12,15L17,10H7Z"
Fill="#FF16CD1C" HorizontalAlignment="Right" VerticalAlignment="Center" Grid.Column="1" Margin="0,0,10,0"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="ToggleButton.IsMouseOver" Value="true">
<Setter TargetName="Border" Property="Background" Value="#E1E1E1" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="ComboBoxItemStyle" TargetType="{x:Type ComboBoxItem}">
<Setter Property="Background" Value="White"/>
<Setter Property="IsSelected" Value="{Binding Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}, Path=IsInDesignMode}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ComboBoxItem}">
<Border Background="{TemplateBinding Background}"
CornerRadius="18"
BorderThickness="{TemplateBinding BorderThickness}">
<ContentPresenter HorizontalAlignment="Center"/>
<Border.Triggers>
<EventTrigger RoutedEvent="MouseEnter">
<BeginStoryboard>
<Storyboard>
<ColorAnimation Storyboard.TargetProperty="(ComboBoxItem.Background).(SolidColorBrush.Color)"
FillBehavior="HoldEnd"
To="#E1E1E1"
Duration="0:0:0.4"/>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
<EventTrigger RoutedEvent="MouseLeave">
<BeginStoryboard>
<Storyboard>
<ColorAnimation Storyboard.TargetProperty="(ComboBoxItem.Background).(SolidColorBrush.Color)"
FillBehavior="HoldEnd"
To="#FFFFFF"
Duration="0:0:0.4"/>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Border.Triggers>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
When I choose any item from the List, it doesn't display.Just a white space. I tried to Bind SelectionBoxItem, but it doesn't work.
I will be so happy if I get answer.
Thanks.

Answer 1

The problem is that your Template doesn't contain ContentPresenter, where to show selected item. It should be here:
<Style x:Key="ComboBoxStyle" TargetType="{x:Type ComboBox}">
<Setter Property="ItemContainerStyle" Value="{StaticResource ComboBoxItemStyle}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ComboBox}">
<Grid>
<ToggleButton Height="{TemplateBinding Height}"
Width="549"
Style="{StaticResource ToggleButtonStyle}"
HorizontalAlignment="Right"
IsChecked="{Binding Path=IsDropDownOpen,Mode=TwoWay,RelativeSource={RelativeSource TemplatedParent}}"
ClickMode="Press"/>
<ContentPresenter Name="ContentSite"
HorizontalAlignment="Left"
VerticalAlignment="Center"
Content="{TemplateBinding ComboBox.SelectionBoxItem}"
ContentTemplate="{TemplateBinding ComboBox.SelectionBoxItemTemplate}"/>
<Popup Name="Popup"...
Also, I'm not really sure your code works as in Combobox's Style Setter there is an IsSelected property. And it has value, that should be assigned to ItemContainerStyle property:
<Setter Property="ItemContainerStyle" Value="{DynamicResource ComboBoxItemStyle}"/>
Also, I would recommend you not to use DynamicResource, if it is not so valuable for you. Use StaticResource instead.