public async virtual Task CallNavigatingToAsync(INavigatingAware vm, INavigationParameter parameter, NavigationModes mode)
{
this.LogInfo();
if (vm == null)
{
return;
}
await vm.OnNavigatingToAsync(parameter, mode);
}
private async Task <bool> InternalNavigateAsync(Type page, INavigationParameter parameter, NavigationModes mode, Func <bool> navigate)
{
this.LogInfo($"page: {page} parameter: {parameter} mode: {mode}");
// if the identical page+parameter, then don't go
if ((page?.FullName == CurrentPage?.GetType().FullName) && (parameter?.Equals(CurrentParameter) ?? false))
{
return(false);
}
// test parameter
if (!parameter.GetType().GetTypeInfo().IsValueType)
{
throw new Exception("Page parameter is not a Value type. Only value types are supported.");
}
// if confirmation required, then ask
var confirmNavigate = CurrentViewModel as IConfirmNavigation;
if (confirmNavigate != null && !await confirmNavigate.CanNavigateAsync())
{
return(false);
}
// call OnNavigatingFrom()
var oldViewModel = CurrentViewModel;
await NavigatingLogic.CallNavigatingFromAsync(oldViewModel as INavigatingAware);
// call onNavigatingTo() if developer-supported
var newViewModel = ViewModelLogic.ResolveViewModel(page);
await NavigatedLogic.CallNavigatedToAsync(newViewModel as INavigatedAware, parameter, mode);
// navigate
Navigating?.Invoke(this, page);
if (navigate.Invoke())
{
CurrentNavigationMode = mode;
Navigated?.Invoke(this, EventArgs.Empty);
}
else
{
this.LogError($"Navigation failed.");
return(false);
}
// call OnNavigatedFrom()
await NavigatedLogic.CallNavigatedFromAsync(oldViewModel as INavigationAware);
// setup or accept view-model
if (CurrentViewModel == null)
{
if (newViewModel == null)
{
CurrentPage.DataContext = ViewModelLogic.ResolveViewModel(CurrentPage);
}
else
{
CurrentPage.DataContext = newViewModel;
}
}
// call OnNavigatedTo()
newViewModel = newViewModel ?? ViewModelLogic.ResolveViewModel(page);
await NavigatedLogic.CallNavigatedToAsync(newViewModel as INavigatedAware, parameter, mode);
return(true);
}
private async Task <bool> InternalNavigateAsync(Type page, object parameter, NavigationModes mode, Func <bool> navigate)
{
return(await InternalNavigateAsync(page, new NavigationParameter(parameter), mode, navigate));
}
public async virtual Task CallNavigatingToAsync(INavigatingAware vm, INavigationParameter parameter, NavigationModes mode)
{
this.LogInfo();
if (vm == null)
{
return;
}
await vm.OnNavigatingToAsync(parameter, mode);
}
