Question

I am trying to create a metro app based on a Developing windows 8 book by Oreilly.

I have the following code, based on the blank metro template

Type rootType = typeof(DependencyObject); 
TypeInfo rootTypeInfo = typeof(DependencyObject).GetTypeInfo(); 
List<Type> classes = new List<Type>(); 
Brush highlightBrush; 

public MainPage()
{
    this.InitializeComponent();
    highlightBrush = this.Resources["ControlHighlightBrush"] as Brush;    

the last line throws this exception. As far as I understand it will search in the common folder the ControlHighlightBrush but if its not present in StandardStyles.xaml file it wont work?

I think thats whats happenning?

An exception of type ‘System.Runtime.InteropServices.COMException’ occurred in mscorlib.dll but was not handled in user code

Additional information: Error HRESULT E_FAIL has been returned from a call to a COM component.

If there is a handler for this exception, the program may be safely continued.

Answer 1

I don’t think it looks in any common folder for resources by default. Resources have to be explicitly specified in the App.xaml in MergedDictionary collection:

<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="Common/StandardStyles.xaml"/>
            <ResourceDictionary Source="Common/CustomStyles.xaml"/>
        </ResourceDictionary.MergedDictionaries>

        <!-- Application-specific resources -->

        <x:String x:Key="AppName">My App</x:String>
    </ResourceDictionary>
</Application.Resources>

So, you would add your custom styles in some file like CustomStyles.xaml and include it as above.