/// <summary>
/// Determines the <see cref="ResourceManager"/> to use for the specified <see cref="DependencyObject"/>.
/// </summary>
/// <param name="obj"></param>
/// <returns></returns>
/// <exception cref="InvalidOperationException">The method is not called on the UI thread of the specified <see cref="DependencyObject"/>.</exception>
public static ResourceManager GetResourceManager(DependencyObject obj)
{
if (obj == null)
{
throw new ArgumentNullException(nameof(obj));
}
obj.VerifyAccess();
var resourceManager = LocalizationScope.GetResourceManager(obj);
if (resourceManager == null)
{
if (DesignerProperties.GetIsInDesignMode(obj))
{
// Window.GetWindow returns "null" at design time
return(GetDefaultResourceManagerForAssembly(DesignTimeHelper.GetDesignTimeAssembly()));
}
else
{
var window = Window.GetWindow(obj);
if (window != null)
{
var localValue = window.ReadLocalValue(DefaultResourceManagerProperty);
if (localValue == DependencyProperty.UnsetValue)
{
resourceManager = GetDefaultResourceManagerForAssembly(window.GetType().Assembly);
window.SetValue(DefaultResourceManagerProperty, resourceManager);
}
else
{
resourceManager = localValue as ResourceManager;
}
}
}
}
return(resourceManager);
}
public override object ProvideValue(IServiceProvider serviceProvider)
{
if (serviceProvider == null)
{
throw new ArgumentNullException(nameof(serviceProvider));
}
if (!(serviceProvider.GetService(typeof(IProvideValueTarget)) is IProvideValueTarget service))
{
return(null);
}
Assembly assembly;
if (service.TargetObject is DependencyObject depObj && DesignerProperties.GetIsInDesignMode(depObj))
{
// WPF Designer uses an instance of "System.Windows.Controls.UserControl" to represent a user control
// (not the actual type) and "Microsoft.VisualStudio.DesignTools.WpfDesigner.InstanceBuilders.WindowInstance"
// to represent a mock window
if (depObj is UserControl || (depObj is FrameworkElement frameworkElement && frameworkElement.Parent == null))
{
// The element is a user control or a root element (e.g. a mock-up window - WindowInstance)
// Check if the object is a mock object or an actual instance. If it is an actual instance then
// the user control is used in another user control or a window
if (depObj.GetType() == typeof(UserControl) || DesignTimeHelper.IsWpfDesignerAssembly(depObj.GetType().Assembly))
{
// The object is a mock object; therefore, use the design-time assembly
assembly = DesignTimeHelper.GetDesignTimeAssembly();
}
else
{
// The object is an actual instance
assembly = depObj.GetType().Assembly;
}
}