Cannot deploy app with style in app.xaml

Question

I have following app.xaml:

<Application>
    ...

    <Application.Resources>
        <!-- Application-specific resources -->
        <ResourceDictionary>
            <viewModels:ViewModelLocator x:Key="ViewModelLocator"></viewModels:ViewModelLocator>
            <ResourceDictionary.MergedDictionaries>
                <!-- 
                    Styles that define common aspects of the platform look and feel
                    Required by Visual Studio project and item templates
                 -->
                <ResourceDictionary Source="/Styles/Styles.xaml"/>

            </ResourceDictionary.MergedDictionaries>
            <Style x:Key="PivotStylePassStore" TargetType="Pivot">
            ...
            </Style>
        </ResourceDictionary>
    </Application.Resources>

</Application>

It builds fine, but cannot it deploy - there is error:

xaml Duplication assignment to the 'Items' property of the 'ResourceDictionary' object

When style entry is removed - there is no problem. What is going on?

Answer 1

Place all your custom/local styles/resources below the MergedDictionaries .

<Application>
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <!-- 
                    Styles that define common aspects of the platform look and feel
                    Required by Visual Studio project and item templates
                 -->
                <ResourceDictionary Source="/Styles/Styles.xaml"/>
            </ResourceDictionary.MergedDictionaries>
            <!-- Application-specific resources -->
            <viewModels:ViewModelLocator x:Key="ViewModelLocator"></viewModels:ViewModelLocator>
            <Style x:Key="PivotStylePassStore" TargetType="Pivot">
            ...
            </Style>
        </ResourceDictionary>
    </Application.Resources>
</Application>

Actually it shouldn't make a difference if they are all above or below, but they have to be together. Application.Resources is a property of Application , everything else is basically the "default" property of the Application XAML Element (kind of like Text for TextBoxes or Content for various others). You can't mix them together.