Say, I want to change from theme 'default' to theme 'XceedMedia' dynamically. What will be code-behind for that.

Let's say,

Dll name is dllName

The inside theme name I wish to use is - themeName

And it is inside 'Themes' folder besides Project.

Following works fine for me - 

ResourceDictionary skin = new ResourceDictionary();

skin.Source = new Uri(@"/dllName;component/" + themeName + ".xaml", UriKind.Relative);

Application app = Application.Current;

app.Resources.MergedDictionaries.Clear();

app.Resources.MergedDictionaries.Add(skin);

Could you please help for the same with Xceed Media Theme?

Got the solution. Just thought to post, in case someone needs exactly the same which I do -

namespace mapping

using Xceed.Wpf.Themes;

using Xceed.Wpf.Themes.Glass;

In code -

if (themeName == "glass")

GlassResourceDictionary xceedSkin = new GlassResourceDictionary();

xceedSkin.LicenseKey = "Write license key here";

..

..