Get robust source URIs for Images in “XAML for Windows Embedded (Compact 2013)” projects

I switch images in the c++ code behind part of a “XAML for Windows Embedded (Compact 2013)” project (also known as "Silverlight for Windows Embedded") like described in this answer.

I use the numbers as URIs that are listed in the generated file PROJECTNAMEGenerated.rc2. It looks like this:

IDR_PROJ_APP             SLWE_XAML DISCARDABLE "XamlPack\\App.Compressed"
IDR_PROJ_DISCLAIMERPAGE  SLWE_XAML DISCARDABLE "XamlPack\\DisclaimerPage.Compressed"
IDR_PROJ_EASTEREGGPAGE   SLWE_XAML DISCARDABLE "XamlPack\\EasterEggPage.Compressed"
IDR_PROJ_MAINPAGE        SLWE_XAML DISCARDABLE "XamlPack\\MainPage.Compressed"
IDR_PROJ_MEASUREMENTPAGE SLWE_XAML DISCARDABLE "XamlPack\\MeasurementPage.Compressed"

105 XAML_RESOURCE DISCARDABLE "..\\Xaml\\Ressources\\BatteryChargerError.png"
106 XAML_RESOURCE DISCARDABLE "..\\Xaml\\Ressources\\BatteryHigh.png"
107 XAML_RESOURCE DISCARDABLE "..\\Xaml\\Ressources\\BatteryLow.png"
108 XAML_RESOURCE DISCARDABLE "..\\Xaml\\Ressources\\disclaimer.png"
109 XAML_RESOURCE DISCARDABLE "..\\Xaml\\Ressources\\easter.jpg"

And it looks like the numbers will change if I add a page or another image.

Any idea how I get a robust URI that I can use for IXRBitmapImagePtr->SetUriSource(src); (or IXRBitmapImage.SetUriSource(src);)?

I also tried to add the images as resources to the application and load them like this:

    BSTR src = TEXT("#IDB_BATTERY_HIGH_CHARGING");
    IXRApplicationPtr app;
    GetXRApplicationInstance(&app);
    HINSTANCE instance = App::GetHInstance();
    IWICBitmap* img = 0;
    HRESULT res = app->LoadImageFromResource(instance,src, L"PNG", &img);
    IXRBitmapImagePtr bitmapImage;
    app->CreateObject(IID_IXRBitmapImage, &bitmapImage);
    res = bitmapImage->SetSource(img);
    m_pBatteryStateImage->SetSource(bitmapImage);

This sets a different image - but the wrong one (and always the same wrong one, no matter which src I define).

I found a solution.

Add your resources again to the "standard" resource file (AppName.rc) and give them an id (you don't have to copy the file, you can use the original path).

e.g.:

 IDB_ERROR  PNG                     "..\\Xaml\\Ressources\\Error.png"

Then you can use this id:

int src = IDB_ERROR;
IXRApplicationPtr app;
GetXRApplicationInstance(&app);
HINSTANCE instance = App::GetHInstance();
IWICBitmap* img = 0;
HRESULT res = app->LoadImageFromResource(instance, MAKEINTRESOURCE(src), L"PNG", &img);
IXRBitmapImagePtr bitmapImage;
app->CreateObject(IID_IXRBitmapImage, &bitmapImage);
res = bitmapImage->SetSource(img);
m_pBatteryStateImage->SetSource(bitmapImage);

The "Silverlight for Windows Embedded Developer's Guide" says it can be done like that (but I didn't try it):

bitmapImage->SetUriSource(L"Assets/ninthAve.png");

And mybe you have to add a "#":

bitmapImage->SetUriSource(L"#Assets/ninthAve.png");