Application level resources & Windows Forms Integration

 
public Form1()
{
    InitializeComponent();
 
    // Create a WPF application 
    var app = new System.Windows.Application();
 
    // Load the ressources
    var resources = System.Windows.Application.LoadComponent(
        new Uri("Styles.xaml", UriKind.Relative)) 
        as System.Windows.ResourceDictionary
 
    // Merge it on application level
    app.Resources.MergedDictionaries.Add(resources);
}