I'm attempting to define a custom xmp schema using BitmapMetadata, and have run into a bit of a hitch.
The short version of my code looks something like this:
BitmapMetadata meta = SomeBitmapFrame.Metadata.Clone() as BitmapMetaData;
meta.SetQuery("/xmp/dc:MyCustomDC", new BitmapMetadata("xmpbag"));
meta.SetQuery("/xmp/dc:MyCustomDC/MyCustomProp", "test string"); // throws exception "Property cannot be found."