public NavigatingEventArgs(DeferralManager manager, NavigatingCancelEventArgs e, Page page, object parameter) : this(manager)
{
NavigationMode = e.NavigationMode;
PageType = e.SourcePageType;
Page = page;
Parameter = parameter;
}
private async void FacadeNavigatingCancelEventHandler(object sender, NavigatingCancelEventArgs e)
{
DebugWrite();
object parameter = null;
try
{
parameter = SerializationService.Deserialize(e.Parameter?.ToString());
}
catch (Exception ex)
{
throw new Exception("Your parameter must be serializable. If it isn't, then use SessionState.", ex);
}
var deferral = new DeferralManager();
var args = new NavigatingEventArgs(deferral, e, Content as Page, parameter);
if (NavigationModeHint != NavigationMode.New)
args.NavigationMode = NavigationModeHint;
NavigationModeHint = NavigationMode.New;
_navigatingEventHandlers.ForEach(x => x(this, args));
await deferral.WaitForDeferralsAsync();
e.Cancel = args.Cancel;
}
public DeferredEventArgs(DeferralManager manager)
{
Manager = manager;
}
public async Task<bool> NavingFromCancelsAsync(object viewmodel, NavigationMode mode, Page sourcePage, Type sourceType, object sourceParameter, Page targetPage, Type targetType, object targetParameter, bool suspending)
{
Services.NavigationService.NavigationService.DebugWrite();
if (sourcePage == null)
{
return false;
}
else if (viewmodel == null)
{
return false;
}
else if (viewmodel is Classic.INavigatingAwareAsync)
{
var deferral = new DeferralManager();
var navigatingEventArgs = new Classic.NavigatingEventArgs(deferral)
{
Page = sourcePage,
PageType = sourcePage?.GetType(),
Parameter = sourceParameter,
NavigationMode = mode,
TargetPageType = targetType,
TargetPageParameter = targetParameter,
Suspending = suspending,
};
try
{
var vm = viewmodel as Classic.INavigatingAwareAsync;
await vm?.OnNavigatingFromAsync(navigatingEventArgs);
await deferral.WaitForDeferralsAsync();
}
catch
{
Debugger.Break();
}
return navigatingEventArgs.Cancel;
}
else if (viewmodel is Portable.IConfirmNavigationAsync)
{
var parameters = new Portable.NavigationParameters();
parameters.Add("NavigationMode", mode.ToPrismNavigationMode());
parameters.Add("SourceType", sourceType);
parameters.Add("SourceParameter", sourceParameter);
parameters.Add("TargetType", targetType);
parameters.Add("TargetParameter", targetParameter);
parameters.Add("Suspending", suspending);
var vm = viewmodel as Portable.IConfirmNavigationAsync;
return !await vm?.CanNavigateAsync(parameters);
}
else
{
return true;
}
}
public NavigatingEventArgs(DeferralManager manager) : base()
{
Manager = manager;
}