WPF Styling nested elements from a style

Question

Similar to this SO question, I am trying to style ComboBoxItems as easily as possible. However, I am making a custom style based on ComboBox's default style found here.

<Style x:Key="MultiComboBox" TargetType="{x:Type ComboBox}">
    <Style.Resources>
        <Style TargetType="{x:Type ComboBoxItem}">
            <Setter Property="Style" Value="{StaticResource MultiComboBoxItem}"/>
        </Style>
    </Style.Resources>

    <Setter Property="SnapsToDevicePixels" Value="true" />
    <!--<Setter Property="OverridesDefaultStyle" Value="true" />-->
    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto" />
    ...
    ...
</Style>
.
.
.
<ComboBox Style="{StaticResource MyComboBox}">
    <ComboBoxItem x:Name="First">First</ComboBoxItem>
    <ComboBoxItem x:Name="Second">Second</ComboBoxItem>
    <ComboBoxItem x:Name="Third">Third</ComboBoxItem>
</ComboBox>

I added the <Style.Resources> bit to the top in hopes to only need one reference here, instead of individually adding it to nested elements, or even needing to add it to the element in the first place. Also, I commented out all of the OverridesDefaultStyle Setters.

However, then I get a XAMLparseexception, "Style object is not allowed to affect the Style property of the object to which it applies". The error makes sense by itself, but I thought since I was targeting ComboBoxItem's it should work. Is there a way around this?

score 8 · Accepted Answer · answered Nov 07 '16 at 19:46

8

Style object is not allowed to affect the Style property of the object to which it applies

the problematic lines are these:

<Style TargetType="{x:Type ComboBoxItem}">
    <Setter Property="Style" Value="{StaticResource MultiComboBoxItem}"/>
</Style>

try rewrite them as

<Style TargetType="{x:Type ComboBoxItem}" BasedOn="{StaticResource MultiComboBoxItem}">
</Style>

or maybe better use ItemContainerStyle property:

<Style x:Key="MultiComboBox" TargetType="{x:Type ComboBox}">

    <Setter Property="ItemContainerStyle" Value="{StaticResource MultiComboBoxItem}" />
    <Setter Property="SnapsToDevicePixels" Value="true" />
    <!--<Setter Property="OverridesDefaultStyle" Value="true" />-->
    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto" />

</Style>

answered Nov 07 '16 at 19:46

ASh

34,632
9
60
82

Thank you. I saw that in the previous question, but the way they acted toward `ItemContainerStyle` made me think it wasn't the right answer for me. Thanks for setting me straight. I'll accept this answer as soon as SO allows me. – Nov 07 '16 at 19:52
Now my question is, how would I do this for a StackPanel? – Nov 08 '16 at 00:18
@SanjayCruze, what exactly should be done for StackPanel? – ASh Nov 08 '16 at 06:33
1

Applying a style to all children of a stackpanel (instead of a combobox), because stackpanels don't have the `ItemContainerStyle` property. I ended up figuring it out though. In the stackpanel style, I added ` ` – Nov 08 '16 at 17:50

WPF Styling nested elements from a style

1 Answers1