/// <summary>
/// Gets the view to which the navigation request represented by <paramref name="navigationContext"/> applies.
/// </summary>
/// <param name="region">The region.</param>
/// <param name="navigationContext">The context representing the navigation request.</param>
/// <returns>
/// The view to be the target of the navigation request.
/// </returns>
/// <remarks>
/// If none of the views in the region can be the target of the navigation request, a new view
/// is created and added to the region.
/// </remarks>
/// <exception cref="ArgumentException">when a new view cannot be created for the navigation request.</exception>
public object LoadContent(IRegion region, INavigationContext navigationContext)
{
if (region == null)
{
throw new ArgumentNullException(nameof(region));
}
if (navigationContext == null)
{
throw new ArgumentNullException(nameof(navigationContext));
}
string candidateTargetContract = GetContractFromNavigationContext(navigationContext);
var candidates = GetCandidatesFromRegion(region, candidateTargetContract);
var acceptingCandidates =
candidates.Where(
v => MvvmHelpers.IsNavigationTarget(v, navigationContext));
var view = acceptingCandidates.FirstOrDefault();
if (view != null)
{
return(view);
}
var activeRegion = _container.Resolve <IActiveRegionHelper>();
activeRegion.ActiveRegion = region;
view = CreateNewRegionItem(candidateTargetContract) as VisualElement;
activeRegion.ActiveRegion = null;
region.Add(view);
return(view);
}