private void Back()
{
this.KeepAlive = false;
// find view by region
var view = this.RegionManager.Regions["MainRegion"]
.ActiveViews
.First(x => MvvmHelpers.GetImplementerFromViewOrViewModel <ToDoDetailControlViewModel>(x) == this);
// deactive view
this.RegionManager.Regions["MainRegion"].Deactivate(view);
this.RegionManager.RequestNavigate("MainRegion", nameof(ToDoListControlView));
}
public BViewModel()
{
this.CloseCommand = new DelegateCommand(() =>
{
this.KeepAlive = false;
// find view by region
var view = this.RegionManager.Regions["MainRegion"]
.ActiveViews
.Where(x => MvvmHelpers.GetImplementerFromViewOrViewModel <BViewModel>(x) == this)
.First();
// deactive view
this.RegionManager.Regions["MainRegion"].Deactivate(view);
});
}
private void ToDetail(TodoDetailData detailInfo)
{
this.KeepAlive = false;
//TODO:情報残るようなら以下のコメントを消す
// find view by region
var view = RegionManager.Regions["MainRegion"]
.ActiveViews
.First(x => MvvmHelpers.GetImplementerFromViewOrViewModel <ToDoListControlViewModel>(x) == this);
// deactive view
this.RegionManager.Regions["MainRegion"].Deactivate(view);
NavigationParameters param = new NavigationParameters();
param.Add("SelectedDetailItem", detailInfo);
this.RegionManager.RequestNavigate("MainRegion", nameof(ToDoDetailControlView), param);
}
private static bool ShouldKeepAlive(object inactiveView)
{
IRegionMemberLifetime lifetime = MvvmHelpers.GetImplementerFromViewOrViewModel <IRegionMemberLifetime>(inactiveView);
if (lifetime != null)
{
return(lifetime.KeepAlive);
}
RegionMemberLifetimeAttribute lifetimeAttribute = GetItemOrContextLifetimeAttribute(inactiveView);
if (lifetimeAttribute != null)
{
return(lifetimeAttribute.KeepAlive);
}
return(true);
}
private void RequestCanNavigateFromOnCurrentlyActiveView(
INavigationContext navigationContext,
Action <IRegionNavigationResult> navigationCallback,
VisualElement[] activeViews,
int currentViewIndex)
{
if (currentViewIndex < activeViews.Length)
{
if (MvvmHelpers.GetImplementerFromViewOrViewModel <IConfirmRegionNavigationRequest>(activeViews[currentViewIndex], out var vetoingView))
{
// the current active view implements IConfirmNavigationRequest, request confirmation
// providing a callback to resume the navigation request
vetoingView.ConfirmNavigationRequest(
navigationContext,
canNavigate =>
{
if (_currentNavigationContext == navigationContext && canNavigate)
{
RequestCanNavigateFromOnCurrentlyActiveViewModel(
navigationContext,
navigationCallback,
activeViews,
currentViewIndex);
}
else
{
NotifyNavigationFailed(navigationContext, navigationCallback, null);
}
});
}
else
{
RequestCanNavigateFromOnCurrentlyActiveViewModel(
navigationContext,
navigationCallback,
activeViews,
currentViewIndex);
}
}
else
{
ExecuteNavigation(navigationContext, activeViews, navigationCallback);
}
}
